Daniel P. Link

Spontaneous Rupture of an Iliac Artery Aneurysm into a Ureter: A Case Report and Review of the Literature

A case of massive hematuria from spontaneous rupture of an iliac artery aneurysm into a ureter is reported. The vascular causes for gross hematuria are reviewed and the various arterial aneurysms are discussed. The need to consider vascular abnormalities when dealing with massive hematuria is emphasized.

Evaluation of Short-term and Long-term Complications after Emergent Internal Iliac Artery Embolization in Patients with Pelvic Trauma

PURPOSE To assess the incidence of long- and short-term complications following internal iliac artery (IIA) embolization after blunt pelvic trauma. MATERIALS AND METHODS One hundred trauma patients with pelvic fractures underwent pelvic angiography from 1994 through 2006. Sixty-seven patients underwent IIA embolization. These patients were retrospectively identified for medical record review. Short- and long-term complications were defined as those occurring at less than or greater than 30 days, respectively. Complications and outcomes were assessed through chart review and, when possible, a standardized questionnaire. Patients who underwent IIA embolization were compared with matched control patients with blunt pelvic trauma who did not undergo pelvic arteriography. Individuals were matched by age, sex, year of admission, and injury scores. RESULTS There were no significant differences in skin necrosis, sloughing, pelvic perineal infection, or nerve injury between embolized and nonembolized patients within 30 days. There was no significant difference in claudication, skin ulceration, or regional pain at a mean of 18.4 months follow-up. In the long term, buttock, thigh, and perineal paresthesia occur at a significantly higher rate in embolized patients. Skin sloughing in the embolized patient group is an important but rare complication. CONCLUSIONS IIA embolization is an important means of controlling pelvic arterial hemorrhage. There is no significant increase in the risk of most evaluated long- and short-term complications in trauma patients who underwent IIA embolization versus those who did not. However, IIA embolization is associated with a marginally significantly increased rate of buttock, thigh, or perineal paresthesia.

Symptomatic spleno-mesenteric-portal venous thrombosis: recanalization and reconstruction with endovascular stents.

PURPOSE To evaluate the safety and efficacy of portal reconstruction in patients with symptomatic spleno-mesenteric-portal venous thrombosis. MATERIALS AND METHODS Portal reconstruction was attempted in 21 patients (seven women, 14 men; mean age, 53.6 years +/- 15.2) with chronic thrombosis of the portal vein alone (n = 8), splenic vein alone (n = 3), or portal, mesenteric, and splenic veins (n = 10). Indications for the procedure were bleeding varices (n = 15), ascites (n = 2), hypersplenism (n = 2), and enteropathy (n = 2). Sixteen procedures were started transhepatically and of these seven were converted to a transjugular intrahepatic portosystemic shunt (TIPS) after successful recanalization of the thrombosed vein. In six patients reconstructions were performed using an intrahepatic portal vein as outflow. Five procedures were performed primarily as TIPS. Wallstents dilated to 7-10 mm were used for reconstruction. The mean follow-up period was 15.2 months +/- 15.9. RESULTS Technical success of portal reconstruction was 85.7% (18 of 21). Thirty-day mortality was 14.3% (three of 21) but was not procedural related. The cumulative rates of survival, primary patency, and palliation at 43 months of follow-up were 61.2% +/- 13.5%, 63.5% +/- 15.3%, and 31.7% +/- 15.7%, respectively. Secondary patency was 79.1% +/- 13.8%. The only predictor of mortality was the presence of liver disease (P = .001, Cox regression). CONCLUSION Portal reconstruction is a safe and effective treatment option for patients with symptomatic chronic portal thrombosis. Liver disease predisposes to a higher mortality.

Indirect computed tomography lymphography using iodinated nanoparticles to detect cancerous lymph nodes in a cutaneous melanoma model

RATIONALE AND OBJECTIVES To evaluate differences in contrast uptake in normal and cancerous lymph nodes on indirect computed tomography (CT) in swine, we conducted lymphographic examinations after subcutaneous injection of a lymphotropic iodinated nanoparticle suspension. METHODS Perilesional subcutaneous contrast injections (2 ml per lesion) of a 15% wt/vol iodinated nanoparticle suspension were made in immature Sinclair miniature swine (n = 5) with cutaneous melanomas. Average attenuation, iodine concentration, node volume, and total iodine uptake were estimated on the CT scans for each opacified lymph node 24 hr after injection. Nodes were classified as normal or cancerous microscopically, and the percentage of tumor replacement was estimated in cancerous nodes. RESULTS Average attenuation and iodine concentration were higher in normal nodes, and total iodine uptake was higher in cancerous nodes with greater than 25% replacement (p < .05). Architectural alterations in opacified cancerous nodes included medullary filling defects, expansile cortical lesions, and disruption of corticomedullary junctions. CONCLUSION Quantitative and qualitative differences in iodinated nanoparticle enhancement characteristics are useful in distinguishing between normal and cancerous lymph nodes on indirect CT lymphography examinations.

Internal pudendal artery stenoses and erectile dysfunction: Correlation with angiographic coronary artery disease

Objectives: To describe the angiographic characteristics of pelvic arterial disease in patients with erectile dysfunction (ED) nonresponsive to phosphodiesterase‐5 inhibitors (PDE5i) and suspected coronary artery disease (CAD). Background: ED and CAD share common risk factors which can result in endothelial dysfunction, atherosclerosis and flow‐limiting stenoses in the coronary and internal pudendal arteries. Methods: Ten patients undergoing cardiac catheterization with ED and a history of unsatisfactory response to a PDE5i were studied. ED severity was quantified using the International Index of ED scoring system. We performed angiography and quantitative vessel analysis of the coronary arteries, bilateral common and internal iliac arteries, and internal pudendal arteries (IPAs). Results: In this pilot observational study, we found a high correlation between the presence of angiographic CAD and IPA disease. The reference IPA diameters at the point of maximal stenosis were 2.7 ± 0.4 mm (right IPA) and 2.7 ± 0.5 mm (left IPA). In the nine patients with IPA disease, the average stenosis severity was 55 ± 31% (right) and 66% ± 25% (left), and average lesion length was 12.4 ± 5.2 mm (right) and 10.0 ± 3.5 mm (left). Four patients had unilateral IPA total occlusions, three of whom had moderate contralateral disease. The majority of IPA stenoses occurred in the mid to distal IPA and appears amenable to percutaneous revascularization. Conclusions: This represents the first angiographic report of CAD correlated with IPA disease in patients with ED. Further investigation is required to determine whether the development of macrovascular disease in the IPA causes ED and whether endovascular treatment is safe and effective in this population.

Histopathologic appearance of arterial occlusions with hydrogel and polyvinyl alcohol embolic material in domestic swine.

PURPOSE This study observes the histologic changes resulting from a hydrogel embolic agent (polyacrylonitrile [PAN]) compared with polyvinyl alcohol particles (PVA) of similar size. MATERIALS AND METHODS Hepatic and renal embolizations were performed in 13 domestic swine by selecting small (1-mm) branches utilizing a coaxial 3-F microcatheter. The hydrogel embolic agent (tantalum-loaded and plain) and PVA were delivered through microcatheters. The longest follow-up period was 8 weeks. Postmortem examination of the embolized tissues included gross examination and histologic analysis. RESULTS Tantalum-loaded PAN particles were radiopaque and seen in groups fluoroscopically and individually with specimen radiography. Histologic studies showed similar luminal and cellular response to PVA and the hydrogel embolic agents. The arterial lesion induced by the hydrogel embolic agents led to an absence of the arterial wall locally in the area of deployment. Hydrogel embolic particles became surrounded in fibrous connective tissue with no arterial wall. PVA and porous hydrogel capsules produced an inflammatory response, resulting in less wall reorganization, and surrounding fibrous connective tissue at 8 weeks than the solid PAN particles. CONCLUSION These hydrogel embolic create a permanent arterial occlusion by transmural arterial damage. Mechanical effects and, to a lesser degree, inflammatory changes are responsible.

Determination of Blood Flow through Arteriovenous Fistulae and Shunts

A videodensitometric method for estimating relative flow was employed in a patient with a bovine arteriovenous fistula. Analogous arteriovenous communications of different sizes were created in two dogs for comparison. Local and general hemodynamic parameters were measured. The videodensitometric method proved to be highly accurate compared to electromagnetic flow readings and is the method of choice in estimating shunt flow in connection with routine angiography.

Venous return and the pneumatic antishock garment in hypovolemic baboons

The pneumatic antishock garment is widely used in trauma patients because it compresses small veins and should augment venous return. If the garment does augment venous return, it should probably be used in all injured patients in shock, regardless of injuries and regardless of anticipated transport time. On the other hand, the garment could distort and narrow large retroperitoneal and abdominal veins and impede venous return. We quantitated venous return in normovolemic and hypovolemic baboons. The garment both augmented and impeded venous return, the two effects counteracting each other. We believe that the pneumatic antishock garment should be used selectively.

Experimental Renal Embolization: Preliminary Results with Polyacrylonitrile-based Multiblock Copolymers

Preparations of polyacrylonitrile (PAN) are now being considered as possible new therapeutic embolization agents. This study evaluated two different liquid PAN formulations and a solid particle form (particle diameters, 100-400 microns). Eighteen rabbits underwent unilateral renal embolization with one of the three different preparations (n = 6 in each group). PAN was effective in causing infarcts in all embolized kidneys, which were documented with both angiograms and pathologic findings. These preliminary results show that PAN may have promise as an effective agent for clinical renal embolizations.

Angiographic determination of splanchnic blood flow.

A new videodensitometric method of measuring blood flow in the splanchnic arteries as a fraction of the cardiac output was compared to electromagnetic flow readings in dogs. A previous investigation regarding the accuracy of the method in vitro was extended to prove that the videodensitometric technique was highly accurate also in vivo. The simplicity of the technique suggests that the videodensitometric method could be used to estimate blood flow in splanchnic arteries during routine angiography.