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Biomedical subjects

G Kretschmer

Publications and source records attributed to G Kretschmer.

At least 55 records · Page 3Linked to original sources
PubMed1992

Dacron versus polytetrafluoroethylene for Y-aortic bifurcation grafts: a six-year prospective, randomized trial.

BACKGROUND: A prospective, randomized trial was conducted to compare Dacron with expanded polytetrafluoroethylene (ePTFE) in reconstructive aortoiliac surgery. No comparable trial with a prospective, randomized design with a comparable number of patients or an equal long-term follow-up period can be found in the literature. METHODS: Between 1984 and 1989, 165 patients were randomized for either Dacron or ePTFE on the basis of age, sex, indication for surgery, diabetes, nicotine consumption, runoff, and operative approach. The two groups were well matched for randomization criteria, as well as the incidence of aneurysms. RESULTS: No statistically significant difference was found between the two graft materials in terms of patency rates (corrected 3-year patency rates: Dacron = 95% vs ePTFE = 95%; Breslow, p = 0.83; Mantel-Cox, p = 0.74). Subgroup analysis comparing long-term patency rates of the two graft materials and relating them to poor runoff, good runoff, aneurysms, and arterial occlusive disease also failed to show any significant differences between ePTFE and Dacron. Early graft failure (n = 6; 3.6% of the patient population; p = 0.045) and severe abdominal graft infection (n = 3; 1.8% of the total population) were seen only in ePTFE grafts. However, these did not affect the corrected long-term patency rate of ePTFE grafts. There were five late graft failures with PTFE (3.0%) and four with Dacron (2.4%). CONCLUSIONS: Graft materials currently available for aortoiliac repair were comparable in terms of corrected long-term patency rates. The alleged advantages of PTFE were not confirmed by our data. PTFE grafts were associated with a higher rate of complications, and more redo operations were required to duplicate the results obtained with Dacron.

Aorta↗
PubMed1991

Extra-anatomic femoro-femoral crossover bypass (FF) vs. unilateral orthotopic ilio-femoral bypass (IF): an attempt to compare results based on data matching.

Some surgeons feel that femoro-femoral suprapubic crossover bypass (FF) is the treatment of choice in unilateral artery disease, whereas others reserve this procedure for the rare high risk patient. Results and their evaluation seem to differ depending upon the indications and the patients elected for comparison. We analysed 57 consecutive patients, who received a FF-PTFE graft between 1977 and 1989 (age 48-95 years; male/female 47/10; preoperative clinical status [Fontaine Classification] St. II: 19%, St. III: 58%, St. IV: 23%; diabetics: 14; smokers: 40). The estimated cumulative primary and secondary patency according to the Kaplan-Meier method were 52 +/- 10% (three grafts at risk) and 63 +/- 10% (six grafts at risk), respectively at 5 years. There was no statistical difference in the secondary patency comparing patients with a good and bad run-off (Breslow, Mantel-Cox). The cumulative 5-year survival was 35 +/- 7% (nine patients at risk). The results were compared with those obtained in a group of 150 patients, in whom an unilateral ilio-femoral (IF) retroperitoneal orthotopic graft had been implanted for the same indication and within the same period. Comparing the primary patency of FF and IF patients (55 +/- 6%; 24 grafts at risk) no significant difference could be seen at 5 years. But there was a significant difference in the 5-year survival rates, being in favour of the IF-group (43 +/- 5%; 43 patients at risk) suggesting that both groups were not comparable.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

[The patency of the external and internal carotid arteries in patients with occlusion of the common carotid: detection using color-coded Doppler sonography].

Common carotid artery occlusion is not necessarily associated with thrombosis of the ipsilateral internal carotid artery. Noninvasive imaging of the carotid bifurcation with colour-coded Doppler sonography demonstrated patency of the external and internal carotid arteries distal to a common carotid occlusion in 4 patients which could be proven surgically. Identification of internal carotid artery patency could be demonstrated by angiography in two of the patients while in the other two cases angiography was inconclusive. Thus, CCDS provided a correct diagnosis of the internal carotid patency in these patients with common carotid occlusion.

Adult↗
PubMed1991

Laser angioplasty: results of a prospective, multicenter study at 3-year follow-up.

A prospective multicenter trial was initiated to evaluate the efficacy and safety of laser angioplasty. Laser recanalization was performed in 338 patients with arteriosclerotic femoropopliteal artery occlusions (average length, 8.5 cm). Neodymium-yttrium-aluminum-garnet lasers were used in combination with sapphire probe catheters. The initial recanalization rate was 85%. Complications were observed in 14% of the patients. Emergency surgery was required in 1.5%. The cumulative long-term patency rate of the successfully recanalized arteries was 80%, 70%, 62%, and 57% at 6 months, 1 year, and 2 and 3 years, respectively. The patency rates were not affected by the length of the occlusion and the long-term medication (platelet inhibition vs anticoagulation), but patients with a normal runoff had significantly better patency rates than those with reduced runoff (63% vs 52%, P less than .01). The study has shown that laser-assisted angioplasty is safe and at least as effective as conventional angioplasty.

Adult↗
PubMed1991

[Therapy and the natural course of axillary vein thrombosis--review of 765 patients and analysis of our personal patient sample].

UNLABELLED: Thrombosis of the axillary vein is a rare event. The incidence of 0.5, -1.5% of all venous thromboses makes comparative studies concerning therapy in a single center impossible. 15 own patients and 750 patients with axillary vein thrombosis collected from literature were studied, to compare the different therapeutic modalities. 36% received no therapy (NV), 15% anticoagulation (AG: heparin, warfarin, coumarins), 18% thrombolytic therapy (TL streptokinase, urokinase, locally and systemic) and 31% were treated by surgery (OP). Mean follow up was 32 months in NV, AG: 16, 3, TL: 35, OP: 38 months. RESULTS: NV; No complaints: 12%, PTS I: 29%, PTS II: 25%, PTS III: 33%. CONCLUSION: Untreated axillary vein thrombosis leads to functional disability of the affected extremity in one third. AG reduces this rate to 25%. After surgery and thrombolytic therapy a severe PTS is found only in 12% and 13.7% respectively. Loss of extremity was found in 5 cases (0.6%). A mechanic factor seems to be important in thrombogenesis. Rapid restitution of venous backflow and promotion of collateralisation is important to avoid disability of the patient. The low difference between AG and OP is pointed out indicating that invasive surgery should be restricted to special cases.

Adult↗
PubMed1991

[The status of carotid artery surgery today: technique, indications, results].

Carotid artery endarterectomy (CAE) is a surgical standard procedure today. The indication is the symptomatic patient (Stage II) with transient ischemic attacks (TIA) and stenosis of the internal carotid artery (ACI). Data of several studies have yielded a highly restrictive policy toward operative procedures in asymptomatic patients (Stage I) with carotid bruit or ACI-stenosis. Furthermore there emerged wide consensus, that patients with frank stroke (Stage III) should not be operated upon. As diagnostic procedures highly advanced non invasive procedures came up during the last decade, as well as computerized tomography and digital subtraction angiography. The operative procedure is performed in general anesthesia with controlled hypertension during the clamping period (n = 650). Perioperative results without using a shunt are not different to those with a shunt. During the last 5 year period our results yielded a 1% perioperative central permanent neurological deficit rate (CPNDR) and a 1% operative mortality. During a 51 months median observation period 1.5% presented again with transient ischemic attacks-with TIA; 0.6% developed a stroke and 2.2% deceased by cerebral complications yielding at totally 4.3% long term complication rate. The annual rates are 0.3%, 0.1% respectively 0.5%, totally 0.9%. In conclusion CAE can be offered as a safe surgical stroke preventing procedure in symptomatic TIA patients with ACI stenoses in our institution. Perioperative as well as long term results are yielding a high standard and are clearly better than those without operation.

Carotid Artery Diseases↗
PubMed1991

[Effect of postoperative aggregation inhibiting therapy following carotid thrombendarterectomy on patient survival. Analysis after more than 15 years follow-up].

The patients in the clinical series as well as in the group with preoperative known cardiac risk receiving postoperative ASA medication yielded a significant better long-term survival results. ASA prolongs long-term survival after carotid endarterectomy. A postoperative ASA-therapy decreases the incidence of lethal cardiac complications.

Aspirin↗
PubMed1991

[Acetylsalicylic acid after iliac-femoro-popliteal interventions?].

To determine whether acetyl salicylic acid (ASA) in a daily dose of 1500 mg versus untreated controls is effective in patients with peripheral arterial disease a prospective randomized but not placebo-controlled one single centre trial was undertaken. Patients were assigned to one of two groups by means of multi-dimensional contingency tables whereas the risk factors age, sex, height, body weight, diabetic metabolic state, hypertension, history of myocardial infarction, smoking habits and preoperative clinical status according to the Fontaine classification where found in the state of balance. 298 patients with arterial occlusions in the iliaco-femoro-popliteal level were recruited during 1971-1974, the primary end points were probability of patency and probability of survival. In regard as well as to the probability of patency (p less than 0.56 Breslow, p less than 0.66 Mantel) as to the probability of survival (p less than 0.10 Breslow, p less than 0.70 Mantel) no statistical significant difference was detected. In conclusion ASA, in the doses administered here, was unable to improve patency or prolong patient survival, an outcome, which is at variance with results obtained by others.

Arterial Occlusive Diseases↗
PubMed1990

[Experiences and clinical results following 99 kidney transplantations with kidneys from relatives].

99 living related kidney transplantations were performed between January 1967 and December 1988. At the time of observation 4 of 94 organ donors had died; there was no correlation between unilateral nephrectomy and the patient's death. Intraoperative (2.9%) and postoperative (25%) complications did not result in severe physical consequences for the organ donors. Hypertension was found in 2 donors. There was no decrease in function of the remaining kidneys. The 3-year organ survival of the transplanted kidney was 60% with "conventional immunosuppression" and 93% with cyclosporin. No association was found between HLA DR-matching and graft survival. Rejection episodes occurred significantly more often in the HLA DR-mismatched grafts.

Adolescent↗
PubMed1990

Antiplatelet therapy following carotid bifurcation endarterectomy. Evaluation of a controlled clinical trial. Prognostic significance of histologic plaque examination on behalf of survival.

To determine whether antiplatelet therapy following carotid bifurcation endarterectomy influences postoperative survival and whether signs of progression in the plaques harvested at the time of surgery might be a prognostic indicator, a controlled clinical trial was undertaken. During 1982 to 1985, 66 patients were recruited, operated on (carotid endarterectomy) and assigned, using the method of adaptive randomisation to the therapy group (n = 32) receiving 1.0 g acetylsalicylic acid (ASA) per day, starting day two prior to surgery, or to the control group (n = 34), which remained without antiplatelet medication. The plaques harvested at the time of surgery were processed using standard histopathological methods and examined "blindly" by light microscopy for signs of arterio-sclerotic progression. The final endpoint was patient survival. The last assessment of the participants survival status was done by June 1989. During follow-up, 20 patients died, six in the treatment group and 14 in the untreated group, the difference being statistically significant (P less than 0.013 Breslow, P less than 0.029 Mantel). In 27 instances the histo-pathological examination showed signs of progression. In this subgroup ASA yielded a significant prolongation of patient survival (P less than 0.017 Breslow, P less than 0.048 Mantel). In the remaining patients no signs of cellular infiltration were evident and no influence of ASA on patient survival was demonstrable (P less than 0.503 Breslow, P less than 0.390 Mantel).

Aged↗
PubMed1990

Antiplatelet treatment prolongs survival after carotid bifurcation endarterectomy. Analysis of the clinical series followed by a controlled trial.

To examine the role of antiplatelet drugs in the secondary prevention of arteriosclerotic arterial disease following carotid endarterectomy, a clinical series (n = 252) was analyzed. Based on these results a prospective randomized trial was initiated, comparing the effect of antiplatelet drugs (acetyl-salicylic acid [ASA] 1000 mg/day) versus untreated controls. In both investigations patient survival was the primary end point. A cardiac risk (n = 91) implied a significant reduction in patient survival (p less than 0.019 Breslow, p less than 0.052 Mantel). Antiaggregating drugs prolonged survival in the collective series (p less than 0.0001 Breslow, p less than 0.0002 Mantel) and in the subgroup of patients with cardiac risk (p less than 0.014 Breslow, p less than 0.020 Mantel) as well. In the prospective trial 66 patients were recruited, receiving ASA (n = 32) versus no therapy (n = 34). During follow-up 15 patients died, 4 in the treatment, and 11 in the control group. Between both groups there was a significant difference in the probability of survival (p less than 0.021 Breslow, p less than 0.048 Mantel).

Aspirin↗
PubMed1990

[Percutaneous transluminal angioplasty following bypass operations on the lower extremities].

To prevent bypass thrombosis, percutaneous transluminal angioplasty (PTA) was performed on 32 stenoses in 25 patients following vascular surgery. Seventeen patients showed 23 stenoses at the level of the anastomoses or in the bypass itself; 8 patients exhibited 9 stenoses proximal or distal to the bypass. Twenty-two patients underwent successful PTA and showed an increase in the ankle/arm Doppler index from 0.38 +/- 0.13 to 0.76 +/- 0.11 after PTA. The long-term patency rates at 6, 12 and 24 months were 75%, 57% and 39%, respectively. The reason for three unsuccessful PTAs are discussed.

Aged↗