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Biomedical subjects

D G Spigos

Publications and source records attributed to D G Spigos.

At least 91 records · Page 5Linked to original sources
PubMed1980

Effectiveness of triglycyl vasopressin in persistent hematuria associated with sickle cell hemoglobin.

Two cases of persistent hematuria associated with the presence of sickle cell hemoglobin were treated intravenously with triglycyl vasopressin, a drug not previously used for this condition. One patient, a 16-year-old boy, had hemoglobin AS. Both patients had a history of severe hematuria persisting over several months, resistant to the usual forms of therapy, and requiring numerous transfusions. In each patient, the condition responded to intravenous triglycyl vasopression therapy, with cessation of hematuria. Experimental studies in dogs indicate that triglycyl vasopressin reduces renal blood flow substantially. Further trial of triglycyl vasopressin in severe hematuria associated with the presence of sickle cell hemoglobin appears to be indicated.

Adolescent↗
PubMed1979

Partial splenic embolization in the treatment of hypersplenism.

Transcatheter embolization of the spleen has been associated with serious complications, such as splenic abscess, rupture of the spleen, pneumonia, and septicemia. These complications, with their grave consequences, have prevented the use of this procedure as an alternative to operative splenectomy in selected cases. A detailed description of our method, which consists of partial splenic embolization, antibiotic prophylaxis, adequate pain control, and careful pre- and postembolization, is reported. Thirteen patients with hypersplenism were successfully treated with transcatheter partial embolization of their spleen.

Adolescent↗
PubMed1977

Skin necrosis following extravasation during peripheral phlebography.

Skin necrosis is an unusual complication following venography of the legs. The authors have found only four cases in the English literature. Two cases of skin necrosis following extravasation of contrast medium are reported. Their pathogenesis, clinical course, and treatment are discussed along with methods of prevention.

Adult↗
PubMed1977

Diagnosis of urine extravasation after renal transplantation.

Urine extravasation in the early postoperative period after renal transplantation is a serious complication requiring expedient surgical intervention. Whereas clinical and laboratory findings are inconclusive, radiologic diagnostic studies have definite value. Routine ultrasound and radioisotope studies were performed on 111 renal transplant patients. In the eight who developed urine extravasation, ultrasound and/or radioisotope studies identified the extravasation in seven cases. Four of the eight were studied by intravenous pyelography and another two were studied by cystography. All results were positive. We recommend use of radioisotope and ultrasound studies for routine postoperative screening with invasive techniques reserved for inconclusive cases.

Adolescent↗
PubMedDate not supplied

Decreased platelet adherence of polymer-coated tantalum stents.

PURPOSE: To compare the acute thrombogenicity of polyurethane-coated stents with that of bare tantalum stents. MATERIALS AND METHODS: Thirty stents (15 coated with polyurethane) were balloon expanded in 8-mm x 80-cm sections of polytetrafluoroethylene grafts (six stents per graft). Under sterile conditions, 8- and 10-F vascular sheaths were placed percutaneously in the femoral artery and vein of a 100-lb (45-kg) swine. Platelets were labeled with indium-111 and reinjected for quantitative assay. The stented grafts were connected to the arterial and venous sheaths to create an ex vivo fistula. Each fistula was opened for 5, 10, 30, 60, or 120 minutes, exposing heparinized blood to fully expanded stents. The fistulas were closed, flushed with saline until clear, and fixed with formalin. Stents were explanted, placed in a radionuclide well counter, and scanned with electron microscopy. RESULTS: Quantitatively, there were considerably fewer platelets on coated versus uncoated stents. At 60 minutes, coated stents averaged 12.93 platelets per 1,000 microns 2 compared with 75.88 platelets per 1,000 microns 2 for bare metallic stents. At 120 minutes, there were 23.22 platelets/1,000 microns 2 versus 102.31 platelets/1,000 microns 2, respectively. Electron microscopy of coated stents demonstrated few scattered platelets at 5, 10, and 30 minutes. There was a uniform layer of platelets at 60 and 120 minutes. Uncoated stents demonstrated random areas of platelet clumping at 5, 10, and 30 minutes. At 60 and 120 minutes, uncoated stents showed extensive layering of platelets and fibrin. CONCLUSION: Polyurethane coating decreases platelet adhesion, relative to bare tantalum, at all time intervals tested.

Animals↗
PubMedDate not supplied

Stent-induced intimal hyperplasia: are there fundamental differences between flexible and rigid stent designs?

PURPOSE: To evaluate possible differences in neointimal development resulting from overdilation of rigid versus flexible vascular stents. MATERIALS AND METHODS: Twelve vascular sheaths were placed bilaterally through femoral arteries in six swine. After angiographic measurement, 12 stents (six flexible and six rigid) were balloon expanded to 8-mm diameters in 12 6-mm iliac arteries (approximately 30% overdilation). All stents were similar in surface area, gauge, and type of wire (tantalum). The primary difference was longitudinal flexibility (low hoop strength) versus rigidity (high hoop strength). Stents were studied with angiography and intravascular ultrasound 5 weeks after implantation. The animals were killed, and the stented segments were removed and examined histologically. RESULTS: Rigid stents maintained larger diameters than flexible stents: mean, 6.52 mm versus 5.82 mm (mean difference, 0.70; standard deviation [SD], 0.47; confidence interval [CI], +/- 0.49; P < .05). In addition, rigid stents developed a thicker, eccentric neointimal reaction relative to flexible stents: mean 1.08 mm versus 0.74 mm (mean difference, 0.338; SD, 0.315; CI, +/- 0.331; P < .05). CONCLUSION: Rigid stents maintain larger diameters over the long term relative to flexible stents when overdilated in normal swine arteries. However, a thicker neointima develops within the lumen of rigid stents at follow-up (greater late loss).

Animals↗
PubMedDate not supplied

Ultrasonography of blood during stasis and coagulation.

A series of in vitro and animal experiments were performed to determine ultrasonic features of blood during stasis and coagulation. Liquid whole blood became echogenic within a few seconds to 3 minutes following the onset of stasis. This occurred in citrated human blood allowed to stand and in occluded segments of vena cava and aorta of dogs. Mechanical agitation of the blood in stasis caused a disappearance of echoes. This echogenicity occurred with gray-scale and real-time ultrasonography using 7.5-mHz transducers, but was not observed with 3.5-mHz transducer used in real-time scanning. Whole blood clot was echogenic both with 7.5- and 3.5-mHz scanning. Fibrin clot was sonolucent. Echogenicity with stasis did not occur with plasma, serum, or packed erythrocytes. The development of echogenicity required the presence of fibrinogen or its products plus erythrocytes. The echogenicity of blood during stasis detectable by high-frequency ultrasonography probably was related to physical layering of blood products. The disappearance of reflective echoes following agitation suggested that the layering could be readily disrupted.

Animals↗
PubMedDate not supplied

Effect of plasma proteins and temperature on echogenicity of blood.

An explanation is proposed for the echogenicity to ultrasound scanning at 5 mHz and above of unclotted blood under conditions of stasis. In vitro experiments using blood from normal subjects and from patients with myeloma revealed that: 1) lysis of red cells prevented echogenicity, 2) echogenicity increased with increasing hematocrit, fibrinogen and other macromolecules, and temperature, and 3) blood from myeloma patients showed increased echogenicity and rouleau formation, a form of aggregation seen on peripheral smears. From these experiments it was concluded that red cell aggregation is a major cause of echogenicity of unclotted blood, requiring both intact red cells and conditions which are known to enhance red cell aggregation, such as the presence of macromolecules and increased temperature.

Blood↗
PubMedDate not supplied

Postmyelographic CT evaluation of multiple blocks due to metastases.

A case of intraspinal metastatic carcinoma that presented on combined cervical and lumbar puncture metrizamide myelography as complete blocks at T2 and T12 is described. The extent of disease in the long segment of the spinal canal was inaccessible to conventional myelography. This case illustrates the importance of postmyelogram CT for accurate assessment of disease and for treatment planning.

Humans↗
PubMedDate not supplied

Adventitial cyst of the popliteal artery: CT-guided percutaneous aspiration.

Adventitial cystic disease of the popliteal artery is a rare condition of uncertain etiology in which a mucinous cyst forms in the wall of the popliteal artery, obstructing the lumen and producing symptoms of intermittent claudication. We report a case in which percutaneous cyst puncture guided by CT resulted in emptying of the cyst contents, with restoration of luminal patency and a normal pulse.

Adult↗
PubMedDate not supplied

Atypical transmural thoracic lipoma: CT diagnosis.

Two cases of transmural thoracic lipomas demonstrate a pattern of rib involvement that has not been previously reported. The lipomas presented with an otherwise characteristic appearance on plain radiography and CT.

Adult↗
PubMedDate not supplied

Cervical esophageal duplication cyst: MR imaging.

Magnetic resonance (MR) imaging was performed in the evaluation of a cervical esophageal duplication cyst in a 9-month-old infant. The value of MR in the assessment of the origin of this cystic lesion as well as the nature of its contents is discussed.

Cysts↗
PubMedDate not supplied

High resolution MRI of the deep brain vascular anatomy at 8 Tesla: susceptibility-based enhancement of the venous structures.

PURPOSE: The purpose of this work was to describe the deep vascular anatomy of the human brain using high resolution MR gradient echo imaging at 8 T. METHOD: Gradient echo images were acquired from the human head using a transverse electromagnetic resonator operating in quadrature and tuned to 340 MHz. Typical acquisition parameters were as follows: matrix = 1,024 x 1,024, flip angle = 45 degrees, TR = 750 ms, TE = 17 ms, FOV = 20 cm, slice thickness = 2 mm. This resulted in an in-plane resolution of approximately 200 microm. Images were analyzed, and vascular structures were identified on the basis of location and course. RESULTS: High resolution ultra high field magnetic resonance imaging (UHFMRI) enabled the visualization of many small vessels deep within the brain. These vessels were typically detected as signal voids, and the majority represented veins. The prevalence of the venous vasculature was attributed largely to the magnetic susceptibility of deoxyhemoglobin. It was possible to identify venous structures expected to measure below 100 microm in size. Perforating venous drainage within the deep gray structures was identified along with their parent vessels. The course of arterial perforators was more difficult to follow and not as readily identified as their venous counterparts. CONCLUSION: The application of high resolution gradient echo methods in UHFMRI provides a unique detailed view of particularly the deep venous vasculature of the human brain.

Arteries↗