PubMed Health⌕ Search

Biomedical subjects

M Geishauser

Publications and source records attributed to M Geishauser.

11 recordsLinked to original sources
PubMed2001

Thromboxane A2 release in ischemia and reperfusion of free flaps in rats, studied by microdialysis.

Several studies have implicated enhanced eicosanoid production in reperfusion injury. The reported study investigated the use of microdialysis in the in vivo measurement of thromboxane levels during reperfusion in ischemic and reperfused experimental free muscle flaps. Microdialysis probes were inserted, via a guide, into the gracilis and semitendinosus free flap in the rat. The probe was perfused at a flow of 5 microl/min, with samples collected at intervals of 20 min, and analyzed by the ELISA technique. Animals were randomly distributed into three groups. After ischemic periods of 2, 4, and 6 hr, respectively, the free muscle flaps were revascularized on the contralateral femoral vessels. The mean thromboxane level during ischemia was 1785.34 +/- 124.81 pg/ml. The mean levels of thromboxane rose significantly (p < 0.05), compared to base level, with 151.65 percent in the 2-hr ischemia group, 192.33 percent in the 4-hr ischemia group, and 294.69 percent in the 6-hr ischemia group, and correlated well with histologic observations. The results suggest that a microdialysis technique, combined with a sensitive assay for measuring thromboxane, is a useful method for in vivo monitoring of inflammatory processes during ischemia and reperfusion. The evolution of thromboxane release following 6 hr of ischemia indicates that this mediator may be involved in facilitation of cell death, following ischemia and reperfusion, since its tissue level correlates with histologic tissue damage.

Animals↗
PubMed2000

[Color comparison of donor sites of free flaps and the face].

Microsurgical reconstructions of the face using free flaps from the body and the extremities often lead to imperfect aesthetic results. In order to find the optimal free-flap donor site with respect to its colour we compared the colour of the face and of typical free-flap donor sites. In a study of 19 healthy, untanned subjects with skin type II-III (Fitzpatrick 1988), we measured the colour of four facial areas and of ten common free-flap donor sites and compared them statistically. Measurements were carried out with a Minolta CR-300 chromameter and the CIELAB colour system. We found that the face itself can be divided into two statistically significant different colour regions. The forehead-, cheek- and mandible areas have a distinctly different colour than the nose. The donor sites showing the best colour match with the forehead-, cheek- and mandible area were pectoralis, lateral upper arm, radialis, fibula, and latissimus. The nose area is clearly darker and less colourful. For this reason the colour match of all the free-flap donor sites in our investigation is poorer. Here the best suited donor site area is still the dorsalis pedis area.

Face↗
PubMed1999

[Free microvascular rectus abdominis muscle flap for soft tissue reconstruction of the lower leg and foot: results and donor site defect].

The free rectus abdominis muscle flap is now a routine procedure for the reconstruction of soft tissue defects in the lower extremity. We present the follow-up of 21 out of 27 patients operated in our clinic between 1986 and 1994. The recipient leg always showed a stable soft-tissue coverage. Clinical or radiological signs of osteitis were not found. In many of the cases, where the transplantion was to the ankle region, the muscle bulk led to an alteration of the shape of the leg, without impairment of function. When harvested through a low transverse abdominal incision, the aesthetic results in the donor site are convincing. The functional donor site defect is negligible as long as only a segment of the muscle is used. Abdominal muscle tests showed good results when only a segment of the muscle was used. The patients reported no impairment in daily life. Abdominal wall weakness was present only when the entire muscle was harvested. There was one hernia after postoperative wound infection and secondary wound healing. In all other cases, the abdominal wall was stable. In the segmental use of the free rectus abdominis muscle flap, the good results obtained in our examination correlate to the high degree of patient satisfaction.

Adult↗
PubMed1998

Donor-site morbidity of the segmental rectus abdominis muscle flap.

The donor-site morbidity of the segmental rectus abdominis muscle flap was evaluated in 20 patients with an average follow-up time of 47 months. Our criteria were based on static and dynamic functional results including relaxation and hernia of the abdominal wall, aesthetic outcome and patient satisfaction. The dynamic functional tests of the abdominal wall showed good results corresponding to the reported minimal impairment of quality of life. There was one abdominal hernia after wound infection and secondary healing. There was no evidence of abdominal wall instability in any of the other patients. The aesthetic outcome was excellent when a transverse lower abdominal incision, asymmetrically elongated to the donor site, was used and moderate in the case of a paramedian vertical incision. Ninety-five per cent of the patients were completely satisfied or satisfied with the result at the donor site. In the segmental use of the free rectus abdominis flap a high degree of subjective patient satisfaction reflects the favourable outcome of our examinations. On the other hand there is a clinically significant functional donor-site defect of this flap. As this procedure is still widely used, and as its indication is closely linked to its absolute and relative donor-site defect, comparisons with the alternatives, e.g. the partial latissimus dorsi muscle flap, the extended gracilis muscle flap or the serratus anterior muscle flap will have to be made.

Abdominal Muscles↗
PubMed1998

The combined gracilis and semitendinosus free flap in the rat.

A free-flap model in rats is presented, that consists of gracilis and semitendinosus muscles pedicled on the femoral vessels, in continuation with deep femoral and saphenous vessels. This flap was transferred to the contralateral side in 40 rats and yielded a 95 percent survival rate. The weight of the flaps averaged 1.65 gm, and the mean pedicle length was 20 mm. The flap is reliable, versatile, and may be used as a muscular, musculocutaneous, or osteomusculocutaneous free flap. The gracilis and semitendinosus muscles may be innervated independently as functioning muscle units. In the musculocutaneous flap, each pedicle may be monitored separately by raising two independently vascularized skin islands. The statistical distribution of the origins of the deep femoral vessels was established in 164 groin dissections; two origins of the vessels not previously described are reported here. The volume of the transferable tissue-about three times more than described in previous studies-and the reliability of the flap make it an ideal microsurgical, experimental model.

Animals↗
PubMed1998

[Information exchange via internet--possibilities, limits, future].

Today, the exchange of information in the Internet is dominated by the WWW and e-mail. Discussion groups like mailing lists and newsgroups also permit communication in groups. Information retrieval becomes a crucial challenge in using the Internet. In the field of medicine, three more aspects are of special importance: privacy, legal requirements, and the necessity of transferring large amounts of data. For these problems, today's Internet doesn't provide a sufficient solution yet. Future developments will not only improve the existing services, but also lead to fundamental changes in the transfer technologies: Safer data transfer is to be ensured by new encrypting software together with the planned transfer protocol IPv6. Introducing the new transfer mode ATM will lead to better and resource saving transmission. Computer, telephone and TV networks will grow together, resulting in convergence of media.

Forecasting↗
PubMed1992

[Carpal tunnel syndrome. The most frequent pressure-induced peripheral nerve lesion].

Carpal tunnel syndrome is the term given to compression neuropathy of the median nerve in the carpal tunnel. It is the most common pressure-induced peripheral nerve lesion. It is typically associated with numbness of the index, long and ring fingers, and nocturnal brachialgia. The diagnosis is supported by the typical clinical symptomatology and the positive Hoffmann-Tinel sign, and is confirmed by the electroneurographic examination (ENG) of the median nerve, which can also be used for follow-up monitoring. During surgery, careful inspection and palpation of the carpal tunnel must be performed to detect such conditions as synovitis, anatomical variants and tumors.

Carpal Tunnel Syndrome↗
PubMed1991

[Pseudarthrosis of the capitate bone with special reference to ligamentous stabilization].

Non-union of the capitate is rare. So far, six cases of non-union have been reported. The authors add a new case report, involving a 29-year old tobacco worker with a typical history. The length of the capitate was restored by corticocancellous bone grafting. The mechanism by which non-union occurs is discussed, showing that the uninjured palmar V ligament in the wrist is responsible.

Bone Screws↗
PubMed1991

[Hypersupination dislocation of the distal radio-ulnar joint after distal radius fracture].

Following an intraarticular distal radius fracture of the scaphoid, scapholunate dissociation and fracture of the ulnar styloid process without dislocation, the distal radius fracture healed with rotational deformity. In the course of conservative treatment, a dislocation of the distal radioulnar joint in locked hypersupination developed. Due to the locked rotational deformity, standard X-rays were difficult to assess. Only with the help of a CAT-scan, were the authors able to visualize the distal radioulnar joint dislocation and later control the postoperative result.

Adult↗
PubMed1989

Coronary arteries in the hypoplastic left heart syndrome. Histopathologic and histometrical studies and implications for surgery.

The subepicardial coronary arteries (CAs) in the hypoplastic left heart syndrome (HLHS) were studied for pathology dependent on the patency of the mitral valve and the presence of endocardial fibroelastosis (EFE) of the left ventricle (LV). Nine heart specimens with aortic and mitral atresia (group 1) were studied and compared with 19 hearts with aortic atresia and mitral stenosis (group 2) (EFE of the LV was present in all cases) and 10 normal hearts. The median age at death was 3 days. For the histological and histometrical studies, 5-mm blocks from six comparable sites of the left (L) and right (R) CAs were serially sectioned and routinely processed. The arterial size and wall thickness were measured. Macroscopically, the CAs in group 1 were normal except for the prevalence of left dominance (56%). In contrast in group 2, the CAs were thicker and tortuous. Histopathology was restricted almost exclusively to group 2 specimens (11 of 19), with the proximal LCAs being the most affected. However, eight hearts with EFE in group 2 had no structural wall changes of the CAs. Histometrically, the sizes (external diameters) of the LCAs and RCAs were similar (0.5-1.0 mm) in groups 1 and 2 and in the normal group; however, we noted an increase in percent medial thickness in group 2 specimens, especially of the LCAs. Furthermore, in some group 2 hearts, the wall thickness (intima and media) relative to the luminal size (internal radius) of proximal and middle LCAs was significantly increased, suggesting the presence of ventricle-CA communications.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic Valve↗