Search PubMed⌕ Search

Biomedical subjects

S Horsch

Publications and source records attributed to S Horsch.

At least 55 records · Page 3Linked to original sources

Vascular anastomoses with absorbable suture material: an experimental study.

A synthetic, monofilament, absorbable suture material, polytrimethylene carbonate, was tested to determine its suitability for use in arterial anastomoses. The material studied is a copolymer made of trimethylene carbonate and polyglycolic acid, with a retention time in the tissue of up to six months. In an experimental group of 12 mongrel dogs, using simple end-to-end anastomoses, aortic and femoral patch grafts of bovine heterograft material and iliofemoral bypass implants of 5 mm of expanded polytetrafluoroethylene prostheses were performed and arteriographically and histologically documented. Direct intraindividual comparisons were made with the absorbable (polytrimethylene carbonate) and nonabsorbable (polypropylene, expanded polytetrafluoroethylene suture) materials, a total of 108 anastomoses. No suture material-related complications such as ruptures or suture line aneurysms occurred. Polytrimethylene carbonate sutures led to less inflammation and scar tissue formation than polypropylene sutures. Complete absorption of the suture material by hydrolytic decomposition was followed by an almost complete regeneration in all layers of the vessel wall. Regeneration of the connective tissue structures of the media was noted. Initial associated reactions in the intima eventually disappeared. Both suture materials were equivalent histologically in the early months of the study, but after 10 month follow-up differences were observed, especially in the structure of the media, apart from the fact that polytrimethylene carbonate is absorbed completely after four to seven months.

Anastomosis, Surgical↗

Longterm study of a compliant biological vascular graft.

Clinically implanted prostheses of biological origin have recently been shown to develop aneurysms within several years. To study this process, recently developed bovine heterografts that were implanted in canine ilio-femoral arteries for 27 to 45 months, were studied in vivo and in vitro. Seven out of seven grafts were patent with only one showing evidence of focal aneurysm. Measurements of mechanical properties, including water permeability, compliance, and burst pressure, and of heat shrink temperature and dry weight were obtained before and after a period of controlled exposure to bacterial collagenase; all data suggested that much of the original graft had been replaced with host tissue. However, enzyme susceptibility was less than that of fresh bovine arteries, indicating that at least some of the grafts' crosslinked collagen was preserved. The compliance of these explants was similar to that reported for autogenous vein. Histological examination of the graft wall revealed cellular "intimal" and adventitial zones containing host-generated collagen surrounding a central zone devoid of cellular infiltration, which appears to be unmodified graft "media" highly resistant to degradation. We conclude that, when properly processed, biological prostheses can act as a bioresorbable scaffold for the orderly replacement of structural elements during healing, promoting continued mechanical integrity of the graft. These promising results encourage the further development of prostheses of biological origin.

Animals↗

[Complications after percutaneous transluminal angioplasty and vascular surgery].

Percutaneous transluminal angioplasty (PTA) is an accepted technique in the treatment of occlusive vascular disease. We report complications associated with balloon catheter dilatation and their treatment in the period from 1. 1. 1986 to 31. 3. 1990. Complications were found at the site of dilatation and the site of insertion of the catheter, mostly in the pelvic and femoral region. Surgical correction was successful in all patients, however three patients died postoperatively of acute myocardial ischemia. To avoid these complications close co-operation between the radiologist performing the dilatation and the vascular surgeon managing the complications should be assured.

Aged↗

[Sonography in suspected appendicitis: a decisive factor in diagnosis and therapy? Results of a prospective study of 669 patients].

The appendectomy-rate in the Federal Republic of Germany is decreasing. German surgeons have begun to refuse appendectomy if there are no signs of acute inflammation. Preoperative assessment of patients with right lower quadrant pain has acquired new significance. The authors report on 2 years of experience with routine use of high-resolution ultrasonography in 669 cases of suspected acute appendicitis. Only 101 patients (= 15.1%) turned out to be suffering from acute appendicitis. Ultrasonography evaluation was found to have a sensitivity of 84.2%, a specificity of 96.8% and an overall accuracy of 94.9%. Ultrasonography was also useful in detecting mimicking diseases of acute appendicitis. Sonography should help to rule out severe disease in the frequent cases of functional abdominal pain.

Acute Disease↗

Intravenous prostaglandin E1 versus pentoxifylline therapy in chronic arterial occlusive disease--a controlled randomised multicenter study.

In a controlled multicenter study 70 patients with chronic arterial occlusive disease stage IV according to Fontaine's classification were randomised to treatment with prostaglandin E1 (PGE1) or pentoxifylline (PX), administered over 4 weeks. Parameters of effectiveness were the reduction of analgesics, the relief of rest pain according to an analogue scale, the improvement of the ulceration according to an ulcer score and the healing of necrotic area. The results show that both forms of treatment produced a significant reduction in analgesic consumption and rest pain. Moreover in both groups a significant reduction of the ulcer score and healing of the necrotic area were observed. Side effects occurred in six patients of the PGE1-group and in ten patients of the PX-group, which required premature discontinuation of treatment in four patients of the PX-group. The study also demonstrated that PGE1 is more effective in the treatment of severe arterial occlusive disease than PX. With respect to the analgesic consumption, the reduction of ulcer score and the healing of necrotic area a significant difference was found in favour of PGE1. In accordance the six months follow-up examinations showed a marked deterioration in the PX-group opposed to the PGE1-group. The intravenous application of PGE1 over a period of 4 weeks in patients with severe arterial occlusive disease seems to be an effective therapeutical principle.

Aged↗

Monitoring of somatosensory evoked potentials in carotid surgery: results, usefulness and limitations of the method.

We have monitored cortical somatosensory evoked potentials (SEP) during 177 carotid operations (167 carotid endarterectomies). An intraluminal shunt was always used for endarterectomy of the internal carotid artery (CEA). SEP was not readable in 21 operations. During 126 carotid operations, no alteration of SEP occurred. However, three patients had an immediate postoperative neurologic deficit while the SEP remained normal. Abnormal SEP occurred in 30 patients. In two cases irreversible loss of SEP was seen. Both patients awoke with a new neurologic deficit after the operation. We found reversible abnormal SEP in 28 cases. In 63 cases with contralateral stenosis, abnormal SEP caused by carotid clamping was observed in 15 (24%). The diagnostic sensitivity of intraoperative SEP monitoring in predicting neurologic outcome following carotid operation was 100% with a specificity of 40%. Monitoring of SEP during carotid surgery is a reliable and useful method to detect incipient cerebral ischemia and to determine the need for shunting. The prognostic value of SEP monitoring to predict postoperative neurologic deficits is limited by the low specificity of the method.

Adult↗

[Surgery of varicose veins. Surgical errors and complications].

It is necessary to distinguish between complications that cannot be avoided and those that can through knowledge of the special risks of the surgical procedure. Special complications that cannot be avoided include bleeding in the saphenous channel, loss of sensitivity, damage of lymphatic vessels, pigmentation of the leg, and the very rare postoperative pulmonary embolization. A preoperative diagnosis based on a careful physical examination, phlebography and Doppler ultrasound will help avert unnecessary mistakes.

Humans↗

[Prostaglandin E1 in stage III and IV arterial occlusive diseases. results of a multicenter study].

In a controlled randomized trial at four centers, using a common protocol, 57 patients with advanced chronic arterial occlusive disease (21 in stage III, 36 in stage IV) were treated with prostaglandin E1 (PGE1) or adenosine triphosphate (ATP) for three weeks. Both substances were administered intraarterially over 60 min. Daily dose of PGE1 was 20 micrograms, of ATP 30 mg. Both produced a significant reduction in resting pain at the end of the treatment phase, in stage III significantly better with PGE1. There was also a clear reduction in the use of analgesics, significantly more so with PGE1. Healing or improvement of ulcers was significantly better with PGE1, while there was no significant differences between the two drugs as regards stage improvement. Three amputations had to be performed in the PGE1 group, nine in the ATP group, a significant difference. Side effects in the form of reddening, pain and swellings occurred in 15 patients of the PGE1 group and six of the ATP group. Final verdict by the treating doctor about the success of treatment was significantly more favorable for PGE1.

Adenosine Triphosphate↗