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S Fraunhofer

Publications and source records attributed to S Fraunhofer.

13 recordsLinked to original sources
PubMed2001

Sympathetic nervous system activity during laparoscopic and needlescopic cholecystectomy.

BACKGROUND: It is difficult to quantify the impact of surgical trauma on patients with conventional measurement techniques. We report our preliminary experience with the determination of sympathetic nervous system activity during laparoscopic and needlescopic cholecystectomy. METHODS: The electroconductivity of representative dermatomes (24 measuring points) was recorded prior, during, and after performing laparoscopic and needlescopic cholecystectomy on 40 consecutive patients according to the method of Nakatani (Ryodoraku). Fifty-five healthy adults served as a control group. RESULTS: Median age in the two groups was 52.4 and 54.1 years, respectively. Prior to the operation and on the 1st postoperative day, sympathetic nervous activity was equal in both groups. In the needlescopic patients, sympathetic activity was lesser at 30 min after the start of the laparoscopic procedure (p <0.05). CONCLUSIONS: The measurement of electroconductivity is a useful noninvasive technique for the evaluation of sympathetic nervous activity. As far as activation of sympathetic nervous system is concerned, the needlescopic technique was found to be superior.

Adult↗
PubMed2000

Intraoperative ultrasonography versus helical computed tomography and computed tomography with arterioportography in diagnosing colorectal liver metastases: lesion-by-lesion analysis.

Helical computed tomography with arterioportography (CTAP) and intraoperative sonography (IOUS) are both recognized to be extremely sensitive in the detection of liver metastases measuring <2 cm in diameter. As sensitivity and specificity values for both techniques differ significantly in the literature and in default of sufficient published data regarding this subject, a lesion-by-lesion analysis was considered necessary. Accuracy of IOUS was compared with helical computed tomography (CT) and portal-phase contrast enhancement (CTAP) in the preoperative detection of liver metastases from colorectal carcinoma projected as a prospective blinded study. Cost efficiency should be determined. Liver CTAP and IOUS were evaluated in 33 patients with colorectal carcinoma. Metastases were resected in 10 cases, and the remaining 23 patients were observed for follow-up with CT investigations every 3 months for a period of 1 year. CTAP and IOUS detected all 13 lesions measuring 5-10 mm (13/13). One metastasis measuring >10 mm was missed by IOUS. CTAP presented an ideal sensitivity of 100%, but specificity was as low as 68%. IOUS sensitivity was 98% and specificity was 95%. IOUS and CTAP are of comparable value regarding the detection of liver metastases <10 mm. Both techniques may be used if resections of synchronous or metachronous metastases are planned in order not to miss limiting small lesions and to prevent superfluous liver surgery. Helical CT scan with dynamic intravenous contrast enhancement is considered the most cost-effective preoperative staging method, although local staging may not be achieved because of insufficient intraabdominal survey.

Adult↗
PubMed1998

Dedicated head-neck coil in MR angiography of the supra-aortic arteries from the aortic arch to the circle of Willis.

PURPOSE: To evaluate the usefulness of a dedicated head-neck coil in preoperative imaging of the supra-aortic arteries. MATERIAL AND METHODS: Forty consecutive patients with suspected carotid artery stenosis underwent MR angiography (MRA). Using a dedicated head-neck coil, we made a complete evaluation of the supra-aortic arteries and graded the internal carotid artery (ICA) stenoses. MRA was performed at 1.5 T with: coronal 3D FISP from the aortic arch to the circle of Willis; transverse 2D FLASH and 3D TONE of the carotid bifurcation; transverse 3D TONE of the carotid siphon and the circle of Willis; and transverse 3D FISP of the aortic arch. I.a. digital subtraction angiography (DSA) was used as the reference. ICA stenoses of 70% and more at DSA (NASCET methodology) were regarded as severe. RESULTS: Severe ICA stenoses were detected with high sensitivity and specificity: 93% and 92% respectively for coronal 3D FISP; 90% and 85% respectively for transverse 2D FLASH; and 97% and 94% respectively for transverse 3D TONE. The carotid siphon and the intracranial ICA were best depicted by 3D TONE. None of the applied sequences gave a satisfactory visualization of the aortic arch or of the origins of the vertebral arteries. CONCLUSION: With the head-neck coil, the supra-aortic arteries (including the intracranial vessels) were visualized without the need to reposition the patient, but depiction of the aortic arch was not acceptable. The quantification of ICA stenoses was reliable.

Aged↗
PubMed1997

MR angiography of the supra-aortic arteries using a dedicated head and neck coil: image quality and assessment of stenoses.

Our purpose was to evaluate a dedicated head and neck coil for demonstration of supra-aortic arteries with optimised magnetic resonance angiography techniques. We performed 47 examinations with a 1.5-T system. We used coronal 3D fast imaging with steady precession (FISP), axial 3D tilted optimised nonsaturating excitation (TONE) and 2D fast low-angle shot (FLASH) for the carotid bifurcation, axial 3D TONE with or without magnetisation transfer (MT) for intracranial arteries, and axial 3D FISP or TONE for the aortic arch. Evaluation included visual assessment of image quality and grading of stenoses near the carotid bifurcation; digital subtraction angiography was used as the reference method. Axial 3D TONE gave superior image quality at the carotid bifurcation, MT-TONE intracranially, and 3D FISP for the aortic arch vessels. Nevertheless, sensitivity and specificity for detection of significant stenoses were similar with coronal 3D FISP (96.3%, 94.0%), axial 3D TONE (92.6%, 92.5%) and axial 2D FLASH (96.3%, 86.6%). Image quality at the aortic arch needs further improvement.

Aged↗
PubMed1994

[High-degree bilateral carotid stenoses].

The indication for carotid endarterectomy in patients with unilateral stenotic lesions as well as the operative risk in patients with bilateral disease is still controversial among experts. We performed a retrospective analysis in our patients with bilateral carotid endarterectomy. 578 patients underwent carotid endarterectomy at our institution from 1986-1992: 54 patients (9.3%) had bilateral carotid disease. 30% of these patients were asymptomatic and 16% had symptoms from both sides. Surgical results concerning the optimal restoration of blood supply (75%) and the occurrence of recurrent stenosis (8%) were comparable for patients with unilateral and bilateral carotid endarterectomy. On the contrary, in patients with bilateral carotid disease, both the operative morbidity (2.8%) and mortality (1.8%) were increased as compared to the total study population (1.9% and 0.45% resp.). Carotid endarterectomy is very effective in preventing stroke especially in patients with multiple vessel disease as compared to the natural history of these lesions.

Aged↗
PubMed1993

Severe bilateral carotid stenosis.

An analysis of the relevant data from the Veterans Affairs Cooperative Study Group in asymptomatic patients, showed that 26 of the 32 ipsilateral strokes occurred during the first two years of clinical follow-up. Furthermore, as observed in the medical group, half the neurologic outcome events were strokes and were not preceded by transient ischemic attacks. In the North American Symptomatic Carotid Endarterectomy Trial over a 2-year period, 45 percent of those with occlusion had a stroke compared to 15 percent in the surgical group. These data dispel the traditionally held view that patients with severe contralateral disease should not be subjected to surgery. However, the referral of patients to centers capable of low rates of surgical complications is essential in a plan that includes carotid endarterectomy with optimal medical management.

Carotid Stenosis↗
PubMed1991

Coagulation in aortofemoral bifurcation bypass grafting.

Few data are available on the pathophysiology of the coagulation system during aortic surgery. Cross-clamping of the aorta, intestinal eventeration and circulatory shock in ruptured aortic aneurysms are thought to cause coagulation disturbances and hyperfibrinolysis. A prospective study of several parameters of the clotting system, i.e. standard clotting tests, platelet count, indicators of fibrinolysis, inhibitors of the clotting cascade and proteases were measured perioperatively in aortobifemoral bypass grafts. Ten patients undergoing elective procedures and two emergency cases with ruptured aortic aneurysms were included. The standard clotting tests reflected the use of heparin. A similar course of ATIII, C1-inhibitor, alpha 2-antiplasmin, plasminogen and fibrinogen with a decrease during the operation and a return to almost normal values postoperatively, were due to intra-operative blood loss, haemodilution and a slight activation of the clotting cascade, as well as, hyperfibrinolysis. This observation was supported by the increased levels of euglobulin lysis and PMN-elastase and the resultant increase in some fibrinogen degradation products, indicating non-specific proteolysis. These changes were more pronounced in the two emergency cases, except for the heparin induced changes in PTT and thrombin time. It is concluded that non-specific proteolysis may be an important factor in the pathogenesis of clotting disorders in surgery of the aorta. Further research is needed to discover the pathways of non-specific proteolysis and its prevention by protease inhibitors.

Aorta, Abdominal↗
PubMed1991

[Measuring regional blood flow in evaluating CT-controlled lumbar sympathetic neurolysis in arterial occlusive disease].

A prospective study was designed to evaluate the effect of CT-guided lumbar sympathectomy in PAOD using the following investigations: 1: laser flowmetry, 2. thermography, 3. plethysmography, 4. thallium scintigraphy. A significant improvement of perfusion was shown. The results of thallium scintigraphy disproved the often claimed steal effect of the muscle perfusion in favor of an increased skin perfusion. 80% of the treated patients experienced relief of their pain. Chemical sympathectomy proved to be as effective as the surgical procedure.

Arterial Occlusive Diseases↗
PubMed1991

[Electronic data processing data bank for vascular surgery as a multiple site system with network connection].

A clinical database, using FileMaker Pro and a network of APPLE Macintosh computers, were created for a vascular surgical unit. The databank presented here is based on proven, routine working procedures of the department. An easily learnable entry facility with hands-on, screen-oriented users' guide and help data file provide easy operability and highly efficient databank capability, along with great flexibility. This criterial and user-friendly features make staff acceptance and compliance readily achievable, thus assuring comprehensive data entry.

Computer Communication Networks↗