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Biomedical subjects

W Sandmann

Publications and source records attributed to W Sandmann.

At least 127 records · Page 7Linked to original sources
PubMed1986

Experimental studies with absorbable and nonabsorbable sutures in infected canine arterial anastomoses.

Vascular anastomoses are usually performed with nonabsorbable synthetic suture material. In an infected wound suture material may have a negative effect on the healing of vascular anastomoses, leading to leakage and formation of false aneurysms. In a canine model 40 neck wounds and 40 groin wounds were contaminated with a standard suspension of Staphylococcus aureus. Subsequently 80 end-to-end anastomoses were performed in both carotid and femoral arteries with the absorbable polydioxanone (PDS) or the nonabsorbable polypropylene (PPL) suture material in one of either side. After wound infection or hemorrhage occurred, or at least 7 days to 6 months after vascular surgery, the dogs were put to death and the contaminated vessels were removed to determine the extent of infection with light and scanning electron microscopy. Macroscopic (presence of pus, anastomotic rupture, or aneurysm) and microscopic findings (absorption, tissue reaction) were compared statistically with the McNemar test. There was no difference in the incidence of wound infection between the sutures examined. Bacteriologic cultures revealed no other microorganism than the inoculated staphylococcus strain or occasional skin contaminants. In the PPL group hemorrhages occurred more frequently (n = 6) than in the PDS group (n = 2; p = 0.125). Anastomotic aneurysms (n = 5) were found only in the PPL group (p = 0.375). These differences, although statistically not significant (because of the small number of the studied anastomoses), suggest the use of monofilament absorbable suture material for autogenous anastomoses in a contaminated area.

Animals↗
PubMed1985

[Inflammatory abdominal aortic aneurysm].

Between January 1, 1970 and March 1, 1985 530 patients underwent graft replacement of the abdominal aorta for infrarenal aortic aneurysms. 28 (5.3%) patients had inflammatory aneurysmal disease, in 3 cases (10.7%) the aneurysm was ruptured. Operation mortality was 17.3%. Characteristic appearance was an unusually thick aortic wall with diffuse, shiny white fibrotic reaction in the retroperitoneum. In most cases the duodenum, inferior vena cava, left renal vein, transverse mesocolon or the ureter were involved into the inflammatory mass. Thoracic aortic involvement was not observed. Contrast CT showed enhancement of the periaortic tissue similar to the blood in the aortic lumen. Standard operation techniques had to be modified to avoid mobilisation of the adherent structures and organs to the aorta.

Aorta, Abdominal↗
PubMed1985

[Autotransfusion in aneurysm surgery].

In a group of selected 65 patients undergoing replacement of the thoraco-abdominal (TAA = 16) or abdominal (AAA = 49) aorta for large aneurysms intraoperative autotransfusion with the cell saver was used to salvage the patients' blood. The mean volumes of retransfused red blood cells were 1.21 (AAA) and 3.61 (TAA) respectively. Mean values for heparin, protein and hemolysis within the last sample of the autotransfused blood were 0.16 IU/ml, 1.24 g/l and 89.5 mumol/l respectively. T1/2 using chrom51 was 21 days. Our results confirm that intraoperative autotransfusion is a valuable and save adjunct in major vascular surgery.

Aorta, Abdominal↗
PubMed1985

Reconstructive vascular surgery for hypertension in renal vascular dysplasia.

28 patients with renovascular hypertension caused by fibromuscular dysplasia involving one or more renal arteries underwent reconstructive surgery. The renal artery stenosis was bilateral in 5 patients. Total artery occlusion occurred in 3 cases. Arteriography was the most useful diagnostic procedure. The operative technique of choice was replacement using saphenous vein or hypogastric artery. All patients survived. On follow-up, 27 patients (96.4%) were either cured or improved. Isotope nephrography suggested restenosis in 1 case. Our results support an aggressive approach to the diagnosis and surgical treatment of renal artery fibromuscular dysplasia causing hypertension.

Adolescent↗
PubMed1985

Parameters of 99mTc-DTPA transfer function in renal artery stenosis.

A new method is presented for decomposition of 99mTc-DTPA renal transfer functions (TF) into their capillary and tubular parts. Amplitudes and mean transit times of both parts were calculated and used for quantitative evaluation of renal perfusion, extraction and transport in 21 patients with renal artery stenosis. The amplitudes showed a positive correlation to the effective renal plasma flow and a negative correlation to the grade of stenosis. The parameters of TF are independent of the contralateral kidney, so they can be used for screening for renovascular disease as well as for pre- and postoperative evaluation of kidneys even in cases of bilateral disease.

Humans↗
PubMed1984

The superiority of combined continuous wave Doppler examination over periorbital Doppler for the detection of extracranial carotid disease.

Non-invasive examination of 431 vessels in 333 patients with cerebrovascular disease in all stages was performed in order to compare the reliability of the periorbital Doppler test alone and together with the more difficult insonation of the carotid arteries in the neck (combined Doppler). These findings were compared with those of subsequent arteriography. Extracranial obstructive (greater than 50%) carotid disease was detected with 100% sensitivity by the combined Doppler, but with only 48% sensitivity by the periorbital indirect test. The specific ability of both methods to identify non-stenotic carotid arteries (less than 50%) was similar at about 98%. Only the combined Doppler examination reliably differentiated various degrees of obstruction, comparable to that obtained with arteriography. Non-obstructive plaques could not be detected or excluded by either Doppler test. More refined methods will be necessary for their evaluation.

Adolescent↗
PubMed1984

[Carotid aneurysm following apparent complications in catheterization of the internal jugular vein].

During resuscitation of a patient wih ruptured abdominal aortic aneurysm his right internal jugular vein was cannulated with a 12 gauge catheter-through-cannula assembly (Cavafix 458, Braun-Melsungen), using a high central approach, without any apparent complications. Five weeks later a dissecting aneurysm of the right common carotid artery developed. From clinical, angiographic and histological data it is very likely that the aneurysm resulted from the catheterization procedure.

Aortic Dissection↗
PubMed1984

Progress in carotid artery surgery at the base of the skull.

From 1977 to 1984, 752 reconstructions of the supra-aortic arteries were performed at our service. In a group of 31 patients presenting with transient ischemic attacks (13) or minor strokes (15), preoperative multiplane angiograms identified lesions from various causes in extremely high locations (fibromuscular dysplasia, 10; atherosclerosis, 6; traumatic changes, 10; spontaneous dissection, 3; and mycotic aneurysms and others, 4) in 34 internal carotid arteries (aneurysms, 10; and stenosis, 24). Surgery was performed on 30 patients. Flow restoration was achieved by resection and vein graft replacement (20), gradual dilatation (5), thromboendarterectomy (6), and tangential clip for exclusion of a lateral aneurysm (1). Only one patient was treated with an extracranial-intracranial anastomosis because the stenosis extended into the carotid siphon. One patient was treated with heparin. Exposure of the internal carotid artery (ICA) at the base of the skull required dissection of the digastric muscle, careful mobilization of the cranial nerves, and detachment of the styloid process in 29 patients. Partial resection of the mastoid process was helpful in two patients. The carotid bone canal was opened from the lateral side in four cases to allow the most distal anastomosis 1 cm within the carotid canal. Back-bleeding was controlled by a balloon catheter. A shunt was impossible to use and clamping time averaged 62 +/- 40 minutes. Except for one recurrent stroke and two transient ischemic attacks no other neurologic deficits occurred. Cranial nerve damage could not be avoided in 21 cases (nervus recurrens, 7; nervus glossopharyngeus, 16; and nervus facialis, 4) but disappeared clinically within a 1- to 6-month period in all but two. Each surgical patient underwent control angiography, which demonstrated 30 arteries to be patent, two became occluded, and one had an insignificant stenosis. We conclude that standard surgical techniques are unsuitable for repair of highly located lesions of the ICA. Although extracranial-intracranial anastomosis has been proposed in patients with planned ligation of the ICA, the anatomic reconstruction remains advantageous because flow is restored to normal and the source of emboli is eliminated. With the use of a special approach, graft replacement can be performed up to the base of the skull.

Adolescent↗
PubMed1983

[Renal artery occlusion. Blood pressure and kidney function before and after surgical treatment].

Angioplasty was performed in 16 patients with renal artery occlusion. It was successful in each of six acute occlusions, although four patients died later of their underlying disease. Two patients are long-term survivors and have normal or compensated renal function up to three years postoperatively. Vessel reconstruction was successful in eight of ten patients with chronic occlusion. In seven there was definite improvement or normalization of the hypertension, in six renal function returned to normal. Thus the success rate as to organ preservation with improvement in pressure and function was 60%.

Adult↗
PubMed1982

[Aneurysm of the internal carotid artery at the base of the skull (author's transl)].

A 15-year-old diabetic boy suffering from recurrent peritonsillar infections developed a mycotic aneurysm of the internal carotid artery at the base of the skull. The aneurysm was approached through a cervical and retroauricular incision. The styloid process was burred down at its base. The sternocleidomastoid muscle and the digastric muscle were resected from the mastoid. The internal carotid artery was clamped proximally and blocked with a balloon-catheter distally. The carotid bone canal was opened 10 mm and the carotid artery resected until normal vessel wall was reached. A vein graft was placed end-to-end with single stitches, using 8 X 0 monofil sutures with a small needle. The postoperative course was uneventful except for a temporary paresis of the peripheral facial nerve. Postoperative angiography revealed restoration of the vessel to normal, the patient is now free of symptoms.

Adolescent↗
PubMed1982

[Blood volume in aorto-femoral bypass operation. Effects of continuous thoracic epidural-, halothane- or neuroleptanesthesia].

49 patients with obliterative arteriosclerotic disease of aortic or iliac artery were tested with three different types of anaesthesia, epidural, halothane, and neuroleptanaesthesia. A normal blood volume was found preoperatively in these patients, i.e. of 75.8 +/- 14.9 ml/kg weight. Connections between blood volume and age or factors of risk were not traced. A patient with a-v fistula showed an obvious increased blood volume (120.2 ml/kg). Intraoperatively the blood volume varied widely during the different types of anaesthesia: while the blood volume increased in epidural anaesthesia (+17%) and remained unchanged by halothane (+1%), it decreased at the same volume load during neuroleptanaesthesia (-17%). A clear connection between changes of cardiac output and changes of the filling potential of the heart (cvp x bv) was found during epidural anaesthesia (r = 0.93). There was no functional connection in the neurolept group (r = -0.08). With halothane changes of filling potential correlated negatively with changes in cardiac output (r = 0.72). A connection between changes of the blood volume and the central venous pressure is evident only in the epidural group (r = 0.59). At the same time these reactions are dependent on the extent of the individual alterations of the vegetative tonus by the epidural block. Those individual changes are even more evident under halothane (r = 0.32) and especially neuroleptanaesthesia (r = 0.28). Therefore we question the control of blood volume by measurement of the central venous pressure for these patients.

Anesthesia, Epidural↗
PubMed1981

[Stenoses and occlusions of the innominate trunk (author's transl)].

Direct comparison with neuroradiologic and surgical data show that stenoses and occlusions of the innominate trunk may be recognized safely by Doppler ultrasound despite localisation close to the aorta. Formation of sonographically demonstrable and haemodynamically complicated vascular by-passes is the reason for the mainly asymptomatic or very uncharacteristic complaints of these cases (78%) among the relatively rare stenosing occlusions of the lumen (0,65%) of the innominate trunk (18 out of 2768 patients). Only in four cases were there focal neurological losses or symptoms of hypoperfusion of the arm. Invasive diagnostic measures should thus be used sparingly. The indication for vascular surgery should be limited to a few cases as long as the natural course of these extracranial vascular changes and the risk of cerebral injury have not been established with certainty.

Adult↗
PubMed1981

[Indications and therapy of obstructive aorto-iliac disease from a surgical viewpoint].

Operative management in patients with aortoiliac disease consists of thrombendarterectomy for unilateral and localised lesions and of aortofemoral/iliac graft implantations for bilateral and extensive lesions. Operative morbidity and mortality depend on the type of anesthesia and are influenced mainly by operating technique. The individual risk of operation depends on the localization of the disease and increases significantly if organ arteries are involved. Therefore, asymptomatic stenosis of the extracranial carotid arteries, renal, and mesenteric arteries have to be recognized, and for significant lesions prophylactical surgical management should be performed. An extensive noninvasive and invasive preoperative diagnostic program will detect asymptomatic stenosis in order to perform prophylactic reconstruction or to exclude those patients from major vascular operations, if the lesion is not accessible. In this particular small group of patients an extraperitoneal approach to the aortic bifurcation or an extra-anatomical bypass like femoro-crossover femoral or iliaco-femoral with revascularization of the profundal femoral artery is recommended. Continuous epidural anesthesia can reduce the risk of operation by reduction of cardial and respiratory complications and, together with the extraperitoneal or extra-anatomical approach the operative trauma is minimized.

Aorta↗