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Biomedical subjects

H Hamann

Publications and source records attributed to H Hamann.

At least 19 recordsLinked to original sources
PubMed1992

Indication for surgery of asymptomatic carotid lesions.

The incidence of cerebrovascular diseases with transient or persistent neurologic dysfunction has increased significantly. Although patients with symptomatic carotid artery stenosis clearly benefit from operative therapy, the indication to prophylactic surgery of asymptomatic carotid lesions however is still controversial. Based on data from a recently completed prospective randomized study and on analysis of the literature the indication and results of surgical treatment of asymptomatic stenoses of the carotid arteries are discussed. From 1970 to 1990 a total of 744 uni-or bilateral reconstructions of the internal carotid artery were performed in 631 patients. The perioperative morbidity (permanent neurologic deficiency) and mortality was 1.1% (n = 8) resp. 0.8% (n = 6). During the follow up period up to 18 years another 9 patients suffered from stroke (1.2%). The annual stroke incidence amounted to 0.2%. An important prerequisite for surgery is the so called critical internal carotid artery stenosis, implying reduced cerebral vasomotor reactivity or high embolic risk of an ulcerative plaque. Proper selection of patients (exclusion of multiple concomitant diseases) and an experienced team of vascular surgeons with operative morbidity and mortality below 1-2% validates surgical treatment of asymptomatic carotid artery stenoses.

Carotid Artery Diseases↗
PubMed1992

[Para-tibial fasciotomy].

Fifty patients with large venous ulcers have been surgically treated by paratibial fasciotomy plus dissection of incompetent perforating veins since January 1990. The operative mortality rate was 0.0%. A single significant complication (hematoma) required a secondary operation. Forty-eight ulcers healed within 8 weeks completely. In two cases, the venous ulcers recurred. Healing could be obtained under conservative treatment. Our results suggest that paratibial fasciotomy is the method of choice for the treatment of chronic deep venous insufficiency stage III after unsuccessful conservative treatment.

Fasciotomy↗
PubMed1990

Morphological characterization of carotid artery stenoses by ultrasound duplex scanning.

Ulcerations and intraplaque hemorrhages are thought to play an important role in the development of neurological deficits in carotid artery stenoses. To assess the ability of duplex scanning to predict plaque morphology we compared different sonographic criteria (plaque border, plaque density, plaque structure) with the morphological findings in 169 consecutive carotid endarterectomies (144 cases with diameter reduction greater than 50%). Two percent of the sonograms were inadequate, and 20% showed poor image quality. Regular plaque borders revealed a smooth or at most minimally ulcerated surface in 92%. Grossly ulcerated stenoses, however, were only found in 27% of the irregular plaques. Moreover, the plaque border was nonvisible in 35% of all cases. Simple, fibro-atheromatous plaques were found to be echogenic in 72% and echolucency was present in 80% of the stenoses with relevant intraplaque hemorrhage. In conclusion, duplex scanning proved to be capable of detecting smooth, fibro-atheromatous stenoses with high accuracy. Ulcerations, however, cannot be predicted reliably, and intraplaque hemorrhage cannot be differentiated from atheromatous debris.

Carotid Arteries↗
PubMed1989

[Value of triad operation in multilevel occlusion].

A triad procedure, i.e., aorto iliac inflow repair + profundaplasty + lumbar sympathectomy, offers a simple and effective approach for revascularisation in patients with multilevel arterial occlusive disease. Approximately 85% of the affected limbs at stage III-IV may return to a stage I or II. Only 10% require an additional distal bypass. Indications, technical aspects and late results are presented.

Aorta, Abdominal↗
PubMed1989

[Determining the amputation level].

The peripheral amputation level (at the knee or below the knee) is the most important factor in obtaining optimal functional results and reducing the relatively high operative mortality of above-knee amputations in patients with occlusive arterial disease. Measurement of transcutaneous oxygen tension has proved to be a helpful tool for realizing this therapeutic principle. Comparison with another group of amputees without pO2 measurement indicates that the ratio of above-knee to below-knee amputation or knee disarticulation could be changed from 2:1 to 1:4. The reduced number of above-knee amputations also resulted in decreased operative mortality (3.2% vs 11.4%).

Amputation, Surgical↗
PubMed1989

[Profound revascularization: a forgotten alternative for multiple vessel reconstruction. A case study].

The profundaplasty represents with the lengthy conical widening of the deep femoral artery in combination with a lumbar sympathectomy L3-L5 a time-saving and effective alternative to multiple and extensive arterial reconstructions in the above and below knee level. An important prerequisite for this method is the exclusion of arteriosclerotic lesions at the aorto-iliac level. Critical selection of the patients and optimal operative technique of the profundaplasty offers results better or at least similar to that of time consuming femoropopliteal resp. cruro-pedal reconstruction. A below the knee reconstruction can always added in case of failure of the profundaplasty. The concentration on the revascularization of the deep femoral artery and reconstruction of the aorto-iliac segment offers a reduction of the operative risk and represents a time saving procedure.

Angiography↗
PubMed1989

[Incidence, causes and follow-up of doubtful smear findings (Papanicolaou group III)].

Suspect smears of 622 patients from 1977-1986 were analysed for their causes and followed up until the definite cytologic or histologic result. In relation to the overall material of 97,963 cases the rate of suspect smears (group Pap. III) was between 1.18 and 0.27%, i.e. an average of 0.68%. The most frequent reasons for the classification "suspect" were inflammatory (42.4%), metaplastic or degenerative changes (16.1%) and doubtful pre-cancer (30.6%). 58% of all cases became negative under cytological control and antimicrobial therapy or hormonal substitution; of these 91.4% converted into negative within 6 months. The histological examination carried out on 230 patients revealed pre-cancer (CIN I-III) in 201 cases; cancer was proved in 5 cases. Compared to the whole population that is a rate of 33.1%. 24 cases were to be found negative. 139 Multiparae (67.6%) were to be found in the group of the 206 histological positive cases. 151 women (74%) had taken hormonal contraceptives. The rate of suspect smears should not exceed one per cent.

Cervix Uteri↗
PubMed1989

[An arterio-cutaneous fistula following attempted thrombolysis and amputation].

This report demonstrates an exceptional case of arteriocutaneous fistula developing after local thrombolysis. The arterial catheter was left in situ for four days and was removed after failure of lumen restoration. A complete ischemia of the lower leg persisted. Following above knee amputation, the patient developed a fistula at the medial side of the stump. Fistulography proved a direct communication with the lumen of the partially recanalized superficial femoral artery. At operation, a suppurative arteritis was found. After complete extirpation of the superficial femoral artery including the transcutaneous fistula, a complete healing could be achieved.

Aged↗
PubMed1988

Early detection and differentiation of periprosthetic fluid accumulation after vascular reconstructive surgery.

Ultrasonographic duplex scanning is used widely to screen the abdominal arterial system and to detect lesions in the extracranial cerebral arteries. Based on clinical studies of 11,712 vascular reconstructions, this report describes the early recognition of fluid accumulation around vascular prostheses. The clinical examination may suggest the typical complications that arise after vascular surgery such as hematoma, pseudoaneurysm, lymphocele, abscess, or perigraft cyst. Duplex scanning, combined with puncture and aspiration, proved to be of great benefit in differentiating the specific type and extent of the complication. Special attention is paid to the so-called perigraft reaction, thought to be a result of an aseptic biological incompatibility to synthetic vascular grafts. It is emphasized that ultrasonographic routine follow-up after vascular surgery is essential for early diagnosis, especially since each complication suspected requires specific therapeutic treatment to prevent exacerbation because of inadequate treatment.

Abscess↗
PubMed1988

Carotid endarterectomy: prevention of stroke in asymptomatic (stage I) and symptomatic (stage II) patients?

This paper reports on 1097 carotid artery operations (651 in stage I and 446 in stage II of cerebrovascular insufficiency) carried out from 1970 to 1988. The indication for surgery was based on the following criteria: hemodynamic efficacy of the stenosis, risk of embolism of the vascular lesion, causal connection between the extracranial stenosis and the neurological deficit, and exclusion of a serious concomitant internal disease. As operation technique, open thrombendarterectomy using an intraluminal shunt was applied. The arteriotomy was closed by means of a patch. When there was a simultaneous elongation of the internal carotid artery (kinking), the internal was shortened with reinsertion into the common carotid artery. In stage I the surgical mortality was 0.9%, and the surgical morbidity (cerebrovascular deficit of ischemic origin) was 1.2%; in stage II the corresponding figures were 1.2% and 2.4% respectively. The period of follow-up observation comprised three to 207 months (up to 17 years) with an average value of 70 months for patients of stage I and 67 months for patients of stage II. Patients of stage I suffered a stroke in 1.4% (n = 9) and patients in stage II suffered a stroke in 2.4% (n = 10) of cases i.e. annually 0.2% in stage I and 0.3% in stage II. There have been various reports on the favorable spontaneous course of patients with carotid stenoses treated non-surgically. A risk of stroke of 1% to 3% was reported for stage I and a risk of stroke of 3% to 4% was reported for stage II.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

[X-ray diagnosis of intimal ruptures of the internal carotid artery. A pathologico-anatomic controlled study].

In a prospective study to determine the accuracy of intravenous DSA in the diagnosis of ulcerative lesions of the internal carotid artery, preoperative findings obtained from DSA in patients with suspected cerebrovascular disease were reviewed and compared with thrombendarterectomy specimen (n = 74). The radiological parameters employed for the assessment of ulcerations were excavations of the vascular contour, ill defined vessel walls and steep plaque surfaces. Overall sensitivity of DSA was 66%, specificity 52%. The depth of excavations proved to be the most accurate sign in detecting ulcerative lesions (sensitivity 83%). However, in rare cases mural recesses with the angiographic appearance of ulceration corresponded to re-endothelialized cavities. Small intimal disruptions with a depth of 0.1 to 1 mm. could not be detected by intravenous DSA.

Arteriosclerosis↗
PubMed1987

[Determination of the degree of stenosis in carotid artery stenoses: ultrasound and i.v. DSA in comparison to surgical findings].

The specimens from 116 consecutive carotid thrombendarterectomies were taken as "gold standard" to evaluate the accuracy of ultrasound methods (duplex scanning + extra-/transcranial Doppler sonography) and intravenous digital subtraction angiography (i.v. DSA) in carotid artery stenoses. In 65 cases, in which the specimens could be gauged reliably, sonography estimated the degree of stenosis in 85% within a range of +/- 10%, in 97% within +/- 20% i.v. DSA was accurate in 52 respectively in 94%. High-grade stenoses were correctly assessed by ultrasound in 90%, by i.v. DSA in 64%. Sonography identified 4/10 kinkings and coilings of the carotid artery, i.v. DSA 9/10. Current available ultrasound methods enable estimation of the diameter reduction of carotid artery stenoses with low deviations. I.v. DSA seems to be less reliable, but can be used favourably as a complementary method to sonography.

Carotid Artery Diseases↗