Tuberculous aneurysm of the aorta presenting with uncontrolled hypertension.

Mycotic aneurysm secondary to tuberculous infection of the aorta is a rare entity with less than 50 cases having been described in the literature. Clinical presentation is usually a consequence of the aneurysm, including pain, palpable mass, or hypovolemia secondary to leak. Definitive treatment is surgical, with nearly 30 documented successful cases. The authors present a case of tuberculous aortitis with mycotic aneurysms that presented with uncontrolled hypertension and occlusion of the right renal artery that underwent successful surgical repair.

Bovine type I collagen as an endovascular stent-graft material: biocompatibility study in rabbits.

PURPOSE: To study the biocompatibility of a bovine type I collagen preparation as a material for small-vessel stent-grafts in rabbits. MATERIALS AND METHODS: A composite nitinol-collagen endovascular stent-graft with a 4-mm inner diameter was deployed in the abdominal aorta in nine rabbits. Angiography was performed, and the rabbits were sacrificed at 1, 2, and 7 days and at 1 and 3 months. The portion of the aorta containing the stent-graft was excised and was histologically evaluated. RESULTS: All stent-grafts were patent at all time points. On days 1, 2, and 7 after implantation, scattered red and white blood cells adhered to the stent-graft. At 1 month, the stent-graft was endothelialized and was infiltrated with fibroblasts that deposited collagen within the interstices of the implanted collagen material. At 3 months, there was additional collagen deposition within the interstices of the stent-graft that did not narrow the lumen of the stent-grafts. CONCLUSION: Type I collagen as a intravascular stent-graft material is biocompatible for at least 3 months in rabbits. It is rapidly endothelialized and does not cause reactive stenosis. As a versatile and biocompatible polymer, collagen is potentially useful in the construction of endovascular stent-grafts for use in human arteries.

Carbon dioxide and gadopentetate dimeglumine venography to guide percutaneous vertebroplasty.

Percutaneous vertebroplasty with polymethylmethacrylate (PMMA) is an effective procedure for relieving pain due to vertebral body compression fractures. The technique employs iodinated contrast venography to exclude needle placement directly within the basivertebral complex. We present two cases in which carbon dioxide (CO2) and gadopentetate dimeglumine venography was used to guide percutaneous vertebroplasty in patients with a contraindication to iodinated contrast.

Renal insufficiency: usefulness of gadodiamide-enhanced renal angiography to supplement CO2-enhanced renal angiography for diagnosis and percutaneous treatment.

PURPOSE: To determine whether gadodiamide is a safe and useful angiographic contrast agent for help in diagnosis and percutaneous treatment of renal artery stenosis in patients with renal insufficiency. MATERIALS AND METHODS: Diagnostic renal angiography and percutaneous renal interventions were performed by using gadodiamide (total dose, 0.3 mmol/kg) and CO2 as intraarterial contrast agents in 25 procedures in 24 patients with renal insufficiency. Serum creatinine levels were obtained within 24 hours before and at 24 and 48 hours after the procedure. Increases in serum creatinine of more than 44 mumol/L were considered clinically important. Gadodiamide-enhanced angiograms were compared with CO2-enhanced angiograms. RESULTS: In 23 (92%) of 25 procedures, there was no increase in serum creatinine level at 48 hours. One patient with acute and chronic rejection of a renal transplant and one with evidence of cholesterol embolization had a clinically important increase in serum creatinine level at 48 hours. No marked increase in creatinine level was observed in patients with relatively low baseline levels (n = 19). Gadodiamide-enhanced angiograms appeared to be better than CO2-enhanced angiograms for help in identifying renal artery occlusions, visualizing renal vessels incompletely filled with CO2, and determining the progress of intervention. CONCLUSION: Gadodiamide appears to be a safe and useful intraarterial contrast agent in patients with renal insufficiency and can be used to supplement or confirm CO2-enhanced angiographic findings.

Percutaneous embolization of a high-flow pancreatic transplant arteriovenous fistula.

Percutaneous endovascular techniques were used to treat an arteriovenous fistula (AVF) associated with pancreatic transplantation. A pancreatic transplant superior mesenteric artery-to-superior mesenteric-vein AVF was successfully embolized while flow to the pancreas transplant was preserved. The embolization was aided by the use of Guglielmi detachable coils and a detachable balloon. No complications were encountered. At 23 months follow-up, the patient is doing well with no recurrence.

Transcatheter treatment of life-threatening lower gastrointestinal bleeding due to advanced pelvic malignancy.

We present two patients with life-threatening, massive, lower gastrointestinal (GI) bleeding and locally advanced cervical carcinoma. Selective pelvic arteriography demonstrated that the site of bleeding originated from a pseudoaneurysm of the right internal iliac artery with fistulous communication to the sigmoid colon in one patient and from the left internal iliac artery into the rectum in the second patient. Transcatheter embolotherapy was then performed using balloon occlusion in one patient and coil embolization in the second patient. The iliac arteries should also be evaluated in patients with pelvic cancer who present with lower GI bleeding.

Effects of systemic heparinization on the thrombogenicity of hydrophilic and nonhydrophilic catheters in a swine model.

We assessed the effect of systemic heparinization on the in-vivo thrombogenicity of various micro- and guiding catheters in a swine model. Microcatheters were placed through 6-F guiding catheters into the common carotid arteries of swine for 30-min (short-term) and 90-min (medium-term) periods, with and without systemic heparinization. At the end of the placement period the microcatheters were retracted through the guiding catheters and fixed for scanning electron microscopy (SEM). Guiding catheters were harvested after 5 h placement, with and without systemic heparinization, by retraction through 8-F sheaths and fixed for SEM. The surfaces of both hydrophilic and nonhydrophilic microcatheters all demonstrated more accumulation of debris during placement without than with systemic heparinization. The difference was primarily in the amount of fibrillary material on the catheter surface. The guiding catheters also demonstrated increased debris accumulation without systemic heparinization. This suggests that, even when using relatively nonthrombogenic catheters, systemic heparinization is indicated during cerebral angiography.

In vivo evaluation of a new type I collagen hemostatic plug for high-risk, large-core biopsies.

PURPOSE: To evaluate in a swine model the hemostatic properties of a new, expansile type I collagen plug for use in high-risk renal biopsies. MATERIALS AND METHODS: Highly purified bovine type I collagen was formed into porous cylindrical plugs and compressed radially to fit into a 5-F delivery system. On hydration these collagen plugs demonstrated radial expansion with approximately 1,600% volumetric expansion ratio. Direct exposure of both kidneys was performed in a 25-kg swine, and a bolus of 3,000 U of heparin was administered to create a coagulopathic state. A 14-gauge Temno coaxial biopsy gun was utilized in performing nine pairs of renal biopsies. The first biopsy of each biopsy pair represented the control biopsy (without collagen plug placement), whereas the second biopsy of each pair represented the plugged biopsy. The presence and duration of hemorrhage from each biopsy site was monitored visually. RESULTS: The biopsy sites without collagen plug showed immediate hemorrhage in nine of nine cases (100%), and in two of nine cases (22%) pulsatile bleeding was noted. With the use of the collagen plug, seven of nine (78%) sites showed immediate hemorrhage, but in no case was pulsatile bleeding noted. Mean bleeding duration was 156 seconds for the control biopsies versus 73 seconds for the biopsy sites plugged with collagen (P = .03, Mann-Whitney rank sum test). Bleeding duration was less than 1 minute in only one of nine (11%) control biopsies compared to six of nine (67%) collagen plug biopsies. CONCLUSIONS: A recently developed, expansile collagen hemostatic plug significantly decreases the duration of hemorrhage at renal biopsy sites in an anticoagulated swine model.

Thrombogenicity of hydrophilic and nonhydrophilic microcatheters and guiding catheters.

PURPOSE: To assess in a swine model the in vivo thrombogenicity of various microcatheters and guiding catheters as a function of catheter material, catheter coating, and duration of implantation. METHODS: Microcatheters (Tracker 18 and Fastracker 18, Target Therapeutics, Fremont, Calif; Magic 1.8, Balt, Montmorency, France; and Transit, Cordis Endovascular Systems, Miami Lakes, Fla) were placed through 6F guiding catheters (Fasguide, Target Therapeutics, and Envoy, Cordis Endovascular Systems) into the common carotid arteries of swine for 30 minutes (short term), 90 minutes (medium term), and 35 days (long term). Guiding catheters were implanted for 5 hours. At the end of the implantation periods the catheters were retracted and fixed for scanning electron microscopy. RESULTS: The surface of the Fastracker microcatheter was devoid of debris after both short- and medium-term implantation. The Tracker microcatheter had minimal accumulation of cellular elements whereas the Transit microcatheter showed moderate accumulation of nondeformed red blood cells. Neither the Tracker nor the Transit microcatheter showed evidence of increasing debris accumulation after medium-term implantation as compared with short-term implantation. The Magic microcatheter was coated with gross thrombus after both short- and medium-term implantation. The Fasguide guiding catheter was nearly devoid of debris, while the Envoy guiding catheter had moderate thrombus formation. Long-term implantation of the Fastracker microcatheter was well tolerated whereas that of the Transit catheter resulted in vessel occlusion. CONCLUSIONS: Hydrophilic microcatheters and guiding catheters are less thrombogenic than their nonhydrophilic counterparts, but not all hydrophilic coatings are equally hypothrombogenic. Degree of thrombogenicity depends on catheter material rather than surface morphology. Medium-term implantation did not yield increasing thrombus formation relative to short-term implantation.

Acute knee trauma: how many plain film views are necessary for the initial examination?

OBJECTIVE: To determine whether anteroposterior (AP) and lateral views of the knee are equivalent to four views in acute fracture detection. DESIGN: Three musculoskeletal radiologists retrospectively interpreted the plain film knee examinations of each patient, establishing ground truth for the presence or absence of a fracture. Cases were presented to four masked senior radiology residents twice--once as a two-view study and again as a four-view study--with 4 weeks separating the two reading sessions to minimize recall bias. Sensitivity, specificity, and diagnostic performance were calculated. PATIENTS: Ninety-two patients presenting to the emergency department with acute knee trauma were evaluated with at least a four-view plain film examination. RESULTS AND CONCLUSIONS: Mean sensitivity for fracture detection using four views (85%) was significantly higher than that using two views (79%). Mean specificity and receiver operating characteristic curve areas were not significantly different using two or four views. Four views are more sensitive than AP and lateral views alone in detection of acute knee fracture.