R. Oser

Predictors of arteriovenous graft patency after radiologic intervention in hemodialysis patients

Arteriovenous grafts in hemodialysis patients are prone to recurrent stenosis and thrombosis, requiring frequent radiologic and surgical interventions to optimize their long-term patency. Little is known about the factors that determine graft outcome after a radiologic intervention. The present study examined the clinical and radiologic predictors of intervention-free graft survival after elective angioplasty or thrombectomy. A prospective computerized database was used to determine the outcomes subsequent to all graft angioplasties (n = 330) and thrombectomies (n = 326) performed at the University of Alabama at Birmingham between April 1, 1996, and June 30, 1999. Primary graft survival rates after angioplasty and thrombectomy were 86% versus 43% at 1 month, 71% versus 30% at 3 months, 51% versus 19% at 6 months, and 28% versus 8% at 12 months, respectively. The median intervention-free graft survival time was substantially longer after angioplasty than thrombectomy (6.7 versus 0.6 months; P < 0.001). The superior outcome of angioplasty over thrombectomy was observed even for the subset of procedures with no residual stenosis (median survival, 6.9 versus 2.5 months; P < 0.001). The median graft survival was inversely related to the magnitude of residual stenosis for both elective angioplasty and thrombectomy. Median intervention-free graft survival after angioplasty was inversely related to the postangioplasty intragraft to systemic systolic pressure ratio (7.6, 6.9, and 5.6 months for ratios <0.4, 0.4 to 0.6, and >0.6, respectively; P < 0.001). Intervention-free graft survival after angioplasty or thrombectomy was not affected by graft location (forearm versus upper arm), number of stenotic sites, or presence of diabetes. In conclusion, graft survival is substantially longer after elective angioplasty than thrombectomy, even when the radiologic appearance after the procedure suggests complete resolution of the stenotic lesion. Moreover, the risk for requiring a subsequent graft intervention can be predicted from two simple radiologic measurements: grade of stenosis and intragraft to systemic systolic blood pressure ratio. These parameters may help determine the frequency of monitoring for recurrent stenosis in a given graft.

Primary Leiomyosarcoma of the Inferior Vena Cava Invading the Right Atrium A Technique for Intraluminal Biopsy Through a Transvenous Approach

Leiomyosarcoma of inferior vena cava (IVC) is a very rare tumor constituting less than 1% of all malignant tumors. However, it is the most common malignant primary IVC tumor. We report a case of primary leiomyosarcoma involving the entire IVC and extending into the right atrium. We also describe a simple endovascular technique that can be used to biopsy IVC masses through a transvenous approach. Our technique can be used as an alternative to percutaneous biopsy which carries a risk of bleeding when transgressing the IVC wall with a biopsy needle. To our knowledge, the use of this technique to biopsy IVC masses has not been described in literature.

Innumerable Bilateral Pulmonary Arteriovenous Malformations Percutaneous Transcatheter Embolization Using Amplatzer Vascular Plug

We report an unusual and distinct case of innumerable bilateral pulmonary arteriovenous malformation (PAVM) in a 42-year-old patient presenting with significant right-to-left shunt resulting in severe dyspnea and with a history of stroke due to paradoxical embolization related to his PAVM. Because it was impossible to treat all his PAVMs, our aim was to treat those with a feeding artery measuring 3 mm or more in diameter, aiming to improve the patient’s dyspnea and decrease the risk of paradoxical embolization. We safely and successfully embolized 8 of the patient’s PAVMs, using a single Amplatzer vascular plug for each PAVM. The procedure did not result in significant improvement of the patient’s symptoms. In similar cases with innumerable PAVMs, the expectations of symptom relief should be lowered and the patient should be informed that treatment will only offer protection from paradoxical embolization. To our knowledge, there are no similar cases previously described in the literature.

Transcatheter Embolization of Extensive Left Gastric Artery Collaterals Presenting With Massive Upper Gastrointestinal Bleed

We report a case of extensive left gastric artery collaterals that were formed in the region of gastric fundus due to splenic artery occlusion and resulted in massive hematemesis. These collaterals were thought to be portosystemic collaterals related to portal hypertension during upper endoscopy study and single-phase venous computed tomography studies. The collaterals were treated by transcatheter endovascular coil embolization. Our case highlights the importance of recognizing and differentiating left gastric artery collaterals from gastric venous varices as a cause of hematemesis since the treatment approach for each condition is totally different. It also introduces the feasibility of percutaneous left gastric artery embolization as a treatment for this condition, without the need for surgical splenectomy and partial gastrectomy which have a higher mortality and morbidity.

Persistent Pulmonary Arteriovenous Malformations: Percutaneous Embolotherapy

Pulmonary arteriovenous malformations (PAVM) are an uncommon entity that interventional radiologists may face in their clinical practice. Many of these lesions are treated successfully using endovascular techniques with satisfactory long-term results. However, some PAVMs respond poorly to initial interventional techniques. This article reviews the signs and symptoms of persistent PAVMs, illustrates different imaging modalities used to diagnose these lesions, and outlines mechanisms by which these lesions may persist. The article highlights techniques and embolic agents used for percutaneous transcatheter embolotherapy of persistent PAVMs and discuss the outcomes of these interventions.

Inferior vena cava filter penetration following Whipple surgical procedure causing ureteral injury

We report a case of an indwelling inferior vena cava filter that penetrated the IVC wall after Whipples pancreatico-duodenectomy procedure performed in a patient with ampullary carcinoma, resulting in right ureteral injury and obstruction with subsequent hydroureter and hydronephrosis. This was incidentally discovered on a computed tomography scan performed as routine follow up to evaluate the results of the surgery. We retrieved the inferior vena cava filter and placed a nephrostomy catheter to relieve the ureteral obstruction. Our case highlights the importance of careful inferior vena cava manipulation during abdominal surgery in the presence of an inferior vena cava filter, and the option of temporary removal of the filter to be placed again after surgery in order to avoid this complication, unless protection is required against clot migration during the surgical procedure.