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Biomedical subjects

K D Hamm

Publications and source records attributed to K D Hamm.

13 recordsLinked to original sources

[Traumatic infraclinoid aneurysms].

Traumatic infraclinoidal aneurysms of the internal carotid artery are rare. They can occur after craniocerebral lesions and can lead to life-threatening haemorrhages from the nasopharyngeal space. Frequently it may take months after the accident before the patient experiences single or repeated rupture bleeding and is referred to acute treatment in an ENT ward. Angiography can confirm the diagnosis and is mandatory to clarify the question of collateral flow in cerebral circulation. In case of local inoperability combined with the need for a ligature of the internal carotid artery, the protective application of an extra-intracranial microvascular anastomosis is an improved safeguard against postoperative deficits. During the past five years five patients suffering from an infraclinoidal aneurysm of the carotid artery have been operated on successfully in this manner. Two of these patients suffered from a traumatic aneurysm; these two case reports are presented.

Adolescent↗

Experimental studies in animals on the use of a fibrin glue from the human plasma fraction Cohn I in nerve reconstruction.

In order to compare the effects of suture and glue direct nerve connections and nerve transplantations in the sciatic nerve in rats were performed. 4, 6 and 12 weeks later, the nerve anastomosis were histologically studied. In the direct nerve connections, despite a single holding suture, dehiscences were frequently detected with the penetration of the adhesive between the nerve ends. Due to the exact adaptation with the aid of inserted nerve grafts, the anastomoses could be repaired sutureless successfully using a fibrin glue cuff. Since histologically, in comparison to suture, no foreign body granulomas were found, the findings in the literature could be confirmed. No cicatricial contractions of the anastomoses could be found. In the interfascicular nerve transplantation, comparatively good results may be obtained using the two-component adhesive on the Cohn I-fraction basis.

Anastomosis, Surgical↗

Fibrin glue on the Cohn I fraction basis in repairing cerebral and dura defects--an experimental study on rats.

The rat skulls were operated upon using a trephine osteoplastically, and a defined cerebral and dura defect was induced. The repair of the cerebral defect was performed with Cohn I glue, or in combination with collageneous fleece. The dura defect was repaired by suture and/or glueing of a split skin or pedicle galeal-periostal flap. Thanks to using Cohn I glue, at all times sufficient venous hemostasis could be achieved, and in combination with collagen fleece the repair was at an optimum. The histological check-up demonstrated that neurotoxic side-effects were absent and there were no conglutinations with the dura. Suturing of the dura was highly time-consuming and impossible when the dura had been removed near the bone. The use of Cohn I adhesive permitted ready and defect repair commonly applicable. At high tension the combined suture-glueing technique proved to be superior.

Animals↗

[A model for microsurgical interference of the rat cranium].

A trepanation model in the rat cranium is represented starting from the permanent enlargement of the microneurosurgical interventions with the necessity of trepanation below the microscope, the suture of the dura mater in regions with difficult access, and the dressing of cerebral tissue defects. A possibility for the microsurgical training is given for the trepanation and the dressing of dural and cerebral defects. Surgical materials and/or drugs for local application can be tested for using them in the neurosurgery too.

Animals↗

[Microsurgical suture and fibrin gluing of nerve anastomoses. Animal experiment study using Cohn I human plasma fraction].

In a comparison of suture and fibrin bonding (using human plasma fraction Cohn I) direct as well as autologous and homologous nerve transplantations were performed in animal experiments. The study was carried out in a total of 66 Nn. ischiadici in Albino Wistar rats. With and without transplants the anastomoses were provided 26 times with the usual microsurgical single-button suture technique and 11 times tith a fibrin adhesive cuff with sequential application of the two components (500 I. U. thrombin/ml, 3,000 units contrycal) or simultaneous application after premixing of the components (5 I. U. thrombin/ml, 50 units contrycal). The qualitative evaluation was carried out after 4, 6, and 12 weeks according to the clinical and histological findings. With the use of sufficiently long transplants the nerve anastomoses could be fixed sutureless with the adhesive cuff more simply than with sutures. Histologically an undisturbed growing forth of the axons without foreign-body reactions and scarred constrictions could be proved. The sutured anastomoses, too, showed a good regeneration; owing to the 2-3 single button-sutures only low-degree tissue reactions occurred around the threads without any greater impairment of the proliferation of the neurites. In case of the direct uniting of the nerves adhesion was only possible in combination with a holding suture. In most cases, however, anastomose dehiscences with a bad result were nevertheless found. The direct nerve suture had to be carried out with 5-7 single-button sutures. In this case, considerably pronounced foreign-body reactions were sometimes found histologically. The nerve regeneration, however, was much better than in case of bonding by adhesion. In contrast to the application in direct nerve joining, the Cohn I adhesive could be used with good results for nerve transplantations.

Anastomosis, Surgical↗

[Percutaneous transluminal dilatation (PTD) of descending stenoses of the vertebral artery].

38 stenoses of supra-aortic arteries were dilated with good success in 32 patients over a period of four years. They were 17 stenoses of the internal carotid artery, one of the common carotid artery, 16 of the subclavian artery, and four descending stenoses of the vertebral artery. Indication, method, and results of percutaneous transluminal dilatation of stenoses descending from the vertebral artery are described and discussed, with reference being made to case examples.

Angioplasty, Balloon↗

[Animal experiment studies of combined suture and glue microanastomoses using a fibrin glue based on the Cohn I human plasma fraction].

A total of 48 end-to-side microvascular anastomoses between the A. and the V. femoralis of Albino Wistar rats were established with and without an additional gluing using the human plasma fraction Cohn I (Cohn-I adhesive) and clinically and histologically examined after 3-4 weeks--group 1 with 4 single button sutures and gluing, group 2 with 8 single button sutures and gluing as well as a control group with the usual suture technique with 12-14 single knob sutures (in each case 16 anastomoses). The time required for anastomosing could not be considerably reduced by the suture-gluing technique. In group 1 the thrombotic occlusion due to vascular wall dehiscences with penetration of the adhesive material into the lumen could not be prevented in eight anastomoses. Owing to the exact vascular wall adaptation with 8 single button (group 2) 14 anastomoses were free just as in the control group. Histologically the tissue-preserving influence of the gluing could be confirmed by the reduction of the number of sutures. Summarising it can be said that the perfectly performed suture technique should continue to play the dominating role, but that the combined suture-gluing technique can be a great help for the surgeon in special cases.

Animals↗

[Neurosurgical aspects of arachnoid cysts].

After an analysis of the patients treated in the last five years, a report is given on 9 cases of arachnoid cysts as a rare form of intracranial space occupation. The etiology of the arachnoid cysts has not been fully cleared up yet, but the semipermeability of the cyst membrane appears to be an important pathogenetic factor. Today, the diagnosis of the disease is verified by CT techniques. In case of the occurrence of clinical symptoms the treatment should always be carried out in the form of an operation.

Adolescent↗

[Adhesive strength studies of biologic tissue adhesives].

Different tissue adhesives including an own fibrin adhesive on the base of the human plasma fraction Cohn I were investigated in relation to their adhesive strength tension. These investigations were carried out on lyophilised skin grafts in vitro. The adhesive strengths were equal in case of the Cohn I adhesive, the Tissucol-Kit and also with Beriplast. These investigations will contribute to optimize an adhesive system.

Adhesiveness↗

[Therapy of giant aneurysms in the region of the base of the skull].

The introduction of microsurgical techniques has given a new impetus to operative therapy of cerebral aneurysms. Method of choice is clip occlusion of the aneurysmal neck, but this goal cannot always be attained. Usually, fusiform shaped aneurysms and so-called giant aneurysms can only be treated by occlusing the feeding vessels. In such cases the preliminary extra-intracranial bypass provides optimal conditions for interrupting the main feeder. Special points of view regarding these rare aneurysms and their haemodynamic relationships to cerebral circulation are discussed. A therapeutical concept is proposed on the basis of three case reports.

Adult↗

[Diagnosis and therapy of intracranial epidermoids].

After a short description of the pathogenesis and morphology of intracranial epidermoids, the clinic symptoms and the diagnosis are dealt with. Therapeutically, it is exclusively a total extirpation with the use of a surgical microscope that can lead to curing. A report is given on nine patients, eight of whom were successfully operated on. It is hardly possible to establish a founded preoperative diagnosis of the kind of the epidermoid. Hypodense space occupying processes in the computer tomogram should, however, give rise to consider differentialdiagnostically also the presence of epidermoids.

Adult↗