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Biomedical subjects

D Trost

Publications and source records attributed to D Trost.

9 recordsLinked to original sources
PubMed2000

Delayed epistaxis resulting from external carotid artery injury requiring embolization: a rare complication of transsphenoidal surgery: case report.

OBJECTIVE AND IMPORTANCE: Delayed epistaxis resulting from trauma to branches of the external carotid artery is an infrequent but potentially serious complication of transsphenoidal surgery. We report two cases of severe, delayed epistaxis in patients who had undergone transsphenoidal surgery. In both cases, noninvasive treatment failed, necessitating endovascular intervention. CLINICAL PRESENTATION: The first patient, a 52-year-old woman with a prolactinoma, underwent a second transsphenoidal resection 18 months after the first surgery. She was readmitted on postoperative Day 15 with massive epistaxis. The second patient, a 40-year-old woman, had undergone two transsphenoidal surgeries, 14 years apart, for an adrenocorticotropic hormone-secreting adenoma. She was readmitted with massive epistaxis on postoperative Day 17. INTERVENTION: Both patients were initially treated with nasal balloon packing but experienced recurrent hemorrhage when the balloon was deflated, necessitating referral to the interventional radiology department for embolization. At arteriography, the first patient was found to have a pseudoaneurysm of the medial branch of the left internal maxillary artery, which was subsequently embolized. Arteriography in the second patient revealed an abnormally dilated midline branch of the right internal maxillary artery in the nasal septum; this vessel was occluded at arteriography. CONCLUSION: Delayed massive epistaxis is a rare but significant complication of transsphenoidal surgery. Injury to branches of the external carotid artery, along with injury to the internal carotid artery, should be suspected in patients who present with delayed epistaxis after transsphenoidal surgery. Angiography performed in patients with refractory bleeding should include selective external carotid injections. Epistaxis that is refractory to anterior and posterior nasal packing may be effectively treated with endovascular embolization.

Adult↗
PubMed1999

[Congenital cardiovascular malformations and chromosome microdeletions in 22q11.2].

BACKGROUND AND OBJECTIVE: Congenital cardiovascular (c-v) malformations are the leading signs of two syndromes of highly variable phenotypes, the DiGeorge syndrome (DGS) and the velo-cardio-facial syndrome (VCFS), both of which in the majority of cases are caused by microdeletion in the chromosome region 22q11.2. It was the aim of this study to ascertain the frequency of these chromosomal abnormalities in patients with unselected congenital cardiovascular malformation, and to assess the type of c-v malformation for which microdeletion analysis of the mentioned region would be indicated. PATIENTS AND METHODS: The cohort consisted of 90 patients with congenital c-v malformations (35 males, 55 females; mean age 3.6 years (19th week of pregnancy-36 years). Most of them were newborns. The c-v anomalies were: ventricular septal defect (n = 20), pulmonary atresia (10), Fallot's tetralogy (9), truncus arteriosus communis (6), aortic valve stenosis (6), atrioventricular canal (6), type B interrupted aortic arch (5), atrial septal defect (5), tricuspid atresia (4), hypoplastic left heart syndrome (4), persisting ductus arteriosus (3), pulmonary valve stenosis (3), complete (third degree) atrioventricular block (2), Ebstein's anomaly (1), tachycardia (1) and enlarged right atrium (1). Four of 14 fetuses included in this study had complex cardiac anomalies that could not be definitively classified. Cytogenetic karyotype analysis was unremarkable in all cases. Microdeletion detection was done by fluorescence-in-situ-hybridization (FISH). RESULTS: 14 of the 90 cases (about 16%) showed microdeletion in the examined chromosomal region 22q11.2. Among the group with microdeletion were aortic arch interruption (5/5), ventricular septal defect (2/20). Fallot's tetralogy (1/9) and atrial septal defect (1/5). All the deletion carriers had other signs of the DGS/VCFS complex. One parent each in two of the microdeletion patients had the same microdeletions. CONCLUSION: In patients with congenital c-v and associated malformations of dysmorphism microdeletion diagnosis of 22q11.2 by FISH is indicated in addition to conventional cytogenetic testing. The incidence of this microdeletion seems to be especially high among patients with type B interrupted aortic arch.

Adolescent↗
PubMed1998

Timing algorithm for bolus chase MR digital subtraction angiography.

To acquire multiple longitudinal locations in the lower extremity after a single contrast injection, appropriate table translation and contrast injection are required. An approximate model based on constant bolus velocity was developed to describe the space-time course of a contrast bolus in the lower extremity. This model was verified in dynamic MR angiograms acquired in a group of patients using time-resolved 2D MR digital subtraction angiography (MRDSA). From this contrast bolus passage model, a timing algorithm for table translation and contrast injection was developed for bolus chase MRDSA, subsequently validated in bolus chase 2D MRDSA experiments. All targeted major peripheral arteries were well depicted in bolus chase 2D MRDSA using this timing algorithm and a single 15-ml contrast dose.

Adult↗
PubMed1996

In vitro model to evaluate the relative efficacy of catheter-directed thrombolytic strategies.

RATIONALE AND OBJECTIVES: Catheter-directed thrombolytic therapy has become an accepted treatment for many vascular occlusions. However, the relative rates of lysis of the different methods of drug administration have not been quantified. We developed an in vitro model to simulate and quantify local lytic therapy of a thrombotic vascular occlusion and tested it by evaluating three catheter-directed lytic strategies. METHODS: Seven-centimeter-long segments of 125I-fibrinogen-labeled thrombus made from recently expired human blood from a blood bank were formed in plastic tubes and were placed in a flowing stream of saline. Using multisidehole catheters, the clots were "treated" with intrathrombic saline or urokinase administered by drip infusion or forced injection using identical total doses of drug and volumes of fluid. Using endhole catheters, saline or urokinase was drip infused into the leading edge of the thrombus using the same protocol. A collimated scintillation detector was used to quantify the amount of activity remaining in the thrombus during each experiment, and the resultant time-activity curves for the different trials were compared. RESULTS: Forced-injection administration of urokinase using a multisidehole catheter produced the fastest lysis, resulting in a half-life of 42 min. The other infusion methods were slower, with half-lives of 153 min for multisidehole urokinase drip infusion, 365 min for endhole urokinase drip infusion, and more than 1,000 min for multisidehole catheter forced injection of saline and multisidehole and endhole saline drip infusion. The differences among these groups were reproducible and statistically significant. CONCLUSION: Results suggest that a simple and inexpensive in vitro model simulating lysis of a vascular occlusion can produce reproducible quantitative data. The data demonstrate that forced injection of lytic agents with a multisidehole catheter enhances the rate of thrombolysis and that the enhancement is not primarily attributable to the mechanical effect of this mode of administration.

Catheterization, Peripheral↗
PubMed1995

High-powered CO2 laser cystoscope for endoscopic bladder surgery.

BACKGROUND AND OBJECTIVE: The CO2 laser is potentially useful for the surgical treatment of superficial bladder tumors. High water absorption of the CO2 laser beam and the lack of a flexible fiber delivery system has hindered development of cystoscopes designed to evaporate bladder tumors. This report describes a cystoscope capable of delivering a high-power CO2 laser beam to all parts of the urinary bladder. STUDY DESIGN/MATERIALS AND METHODS: A rigid 24 Fr. cystoscope transmitting 80 Watts of power via an articulated arm and infrared waveguide was built. Beam manipulation is by reflection using a movable mirror. Smoke and urine are evacuated by continuous flow of CO2 purge gas. An isotopic laser delivering an 11.1 micron wavelength beam prevents resonant absorption. Conventional 30-70 degrees telescopes are used. Scope performance and lesion morphology were tested in four female pigs. RESULTS: A total of 80-85% of the incident energy is delivered to the mucosa. All areas of the bladder mucosa can be evaporated. All components tolerate wetting. Mucosa and lamina propria are evaporated with 30 Joules of delivered energy. Perforation occurs after 120-160 Joules are delivered to a single spot. CONCLUSION: The limitations of power, beam transmission, beam manipulation within a small cavity, and resistance to wetting have been overcome.

Absorption↗
PubMed1994

13CO2 isotopic laser used through the operating channel of laser laparoscopes: a comparative study of power and energy density losses.

OBJECTIVE: To evaluate the power transmission, spot size, power density, and energy density of a new isotopic carbon dioxide (13CO2) laser compared with a conventional CO2 laser. METHODS: Experiments were performed in a laboratory using a conventional CO2 laser and an isotopic 13CO2 laser. Two laparoscopes with 5-mm and 7.5-mm operating channels were connected to a standard coupler and to each of the lasers. Standardized measurements were made of power transmission and spot size using both nitrogen purge gas and CO2 purge gas at rates of 1-20 L/minute. Power density and energy density were calculated for continuous mode and ultrapulse mode transmission, respectively. RESULTS: The isotopic 13CO2 laser power transmission was higher and proportional to input power, while spot size was smaller compared with the conventional laser and was insensitive to power level or purge rate. Power density and energy density were markedly higher with the isotopic 13CO2 laser, reaching the threshold for complete ablation, and were much more predictable. The 7.5-mm operating channel generally had superior operating results compared with the 5-mm channel because of the smaller spot size and higher power transmission. CONCLUSIONS: The isotopic 13CO2 laser is associated with much higher power density and energy density capabilities than are conventional CO2 lasers. At surgery, we have noted less thermal injury, faster ablation, more precise and predictable tissue effects, and greater control of tissue effect with the isotopic 13CO2 laser than with other CO2 lasers. These results are attributed to the improved beam propagation through CO2 insufflation gas measured in the laboratory. Thermal injury can be varied according to the required surgical situation and can be kept to an absolute minimum at high-pulse energy.

Carbon Dioxide↗
PubMedDate not supplied

Is Hughes-Stovin syndrome Behçet's disease?

Hughes-Stovin syndrome (HSS) is a rare clinical disorder, which has been described as the presence of pulmonary artery aneurysm in the setting of systemic thrombosis. The term "Incomplete Behçet's Disease" has also been used to describe this syndrome due to the clinical and histopathological similarities between Behçet's disease and HSS. Indeed, pulmonary involvement can be indistinguishable between these two conditions of unknown pathophysiology. We describe an HSS patient who presented with a recurrent pulmonary artery aneurysm, review the clinical and pathological manifestations of HSS, discuss its similarities to Behçet's disease, and finally make the argument that HSS is in fact Behçet's disease.

Adult↗