Ian A. Sproat

Peripheral vascular disease and renal transplant artery stenosis: a reappraisal of transplant renovascular disease

Background: Renal transplant artery stenosis (RTAS) continues to be a problematic, but potentially correctable, cause of post‐transplant hypertension and graft dysfunction. Older transplant recipients, prone to peripheral vascular disease (PVD), may have pseudoRTAS with PVD involving their iliac system.Methods: We retrospectively analyzed 819 patients who underwent kidney transplantation between 1993 and 1997 to determine the contribution of pseudoRTAS to renal transplant renovascular disease. Univariate analyses were performed for donor and recipient variables, including age, weight, gender, race, renal disease, cholesterol and creatinine values, human leukocyte antigen (HLA) matching, cytomegalovirus (CMV) infection, and immunosuppressive medications. Significant variables were then analyzed by a Cox proportional hazards model.Results: Ninety‐two patients (11.2%) underwent renal transplant arteriogram (Agram) or magnetic resonance angiography (MRA) for suspected RTAS. RTAS or pseudoRTAS, defined as one or more hemodynamically significant lesions in the transplant artery or iliac system, was evident in 44 patients (5.4%). Variables significantly associated with RTAS by univariate analysis were weight at the time of transplant (p=0.0258), male gender (p=0.034), discharge serum creatinine> 2 mg/dL (p=0.0041), and donor age (p=0.0062). Variables significantly associated with pseudoRTAS by univariate analysis were weight at the time of transplant (p=0.0285), recipient age (p=0.0049), insulin‐dependent diabetes mellitus (IDDM; p=0.0042), panel reactive antibody (PRA) at transplant (p=0.018), and body mass index (p=0.04). Weight at transplant and donor age remained significantly associated with an increased risk for RTAS in a multivariate stepwise Cox proportional hazards model. IDDM, transplant PRA, weight at transplant, and donor age were significantly associated with an increased risk for pseudoRTAS in a multivariate stepwise Cox proportional hazards model. Importantly, both RTAS and pseudoRTAS were associated with poorer graft survival (p<0.007 for each).Conclusions: Renal transplant renovascular disease encompasses pre‐existing PVD acting as pseudoRTAS, as well as classical RTAS. Efforts to identify and correct renal transplant renovascular disease of either nature are important, given its negative impact on graft survival.

The Bird's Nest Inferior Vena Caval Filter: Review of a Single-Center Experience

PURPOSE To examine a large single-center experience with Birds Nest vena caval filters for indications, clinically evident recurrent thromboembolic disease, and other filter-related complications. MATERIALS AND METHODS During a 6-year period, 308 patients underwent percutaneous placement of an inferior vena caval filter. The 267 patients who received a Birds Nest filter are the subject of this retrospective review. The series included 162 men and 105 women who ranged in age from 16 to 88 years (mean, 57.1 +/- 17.0 standard deviation). RESULTS Indications for filter placement included contraindication to anticoagulation (n = 141), complication of anticoagulation (n = 23), failure of anticoagulation (n = 30), failure of previously placed filter (n = 1), and prophylaxis (n = 82). Ten patients had more than one indication. Acute lower extremity deep venous thrombosis was confirmed in 133 patients, pulmonary embolism (PE) was found in 44 patients, and both were positively diagnosed in 37 other patients. Fifty-three patients had no documented acute thromboembolic disease at the time of insertion. Mean follow-up was 13 months. Thirty-day mortality was 9.7%, including one death from recurrent PE and one major puncture-site bleeding episode that may have contributed to death. Recurrent PE was found at radionuclide scanning or autopsy in three patients (1.1%), whereas another eight patients (3.0%) had suspected recurrent PE without confirmatory studies. Eight patients (3.0%) developed early venous access site thrombosis, including two who progressed to phlegmasia cerulea dolens with fatal complications. Significant nonthromboembolic problems were encountered in 1.9% of patients. CONCLUSIONS The Birds Nest filter is a safe and effective device for patients with complicated venous thromboembolic disease.

Multidisciplinary approach to deep-seated lesions requiring radiologically-guided fine-needle aspiration

Fine‐needle aspiration (FNA) is a diagnostic modality that continues to improve in accuracy as training and experience accumulate. With increasing operator expertise and improved localization techniques, greater numbers of patients are able to benefit from FNAs performed on sites that are otherwise difficult or dangerous to reach by conventional surgery. We present a retrospective review of a 2‐yr experience with radiologically‐guided deep‐seated FNA. In 115 cases involving transthoracic and transabdominal sites, we achieved the following overall figures: 91.9% sensitivity, 100% specificity, 93.9% diagnostic accuracy, 100% positive predictive value, and 80.6% negative predictive value. Our results are compared to those in other series.

Diagnosis of recurrent Desmoplastic small round cell tumor by fine needle aspiration : A case report

BACKGROUND Desmoplastic small round cell tumor (DSRCT) is a recently described neoplasm characterized by aggressive biology, occurrence in body cavities, expression of antigens from multiple cell lineages and a specific translocation between chromosomes 11 and 22. Most of the published information on this neoplasm is histologic. The case presented here enabled presentation of the cytomorphologic and immunocytochemical features of aspirated cytologic material obtained from this unique tumor. CASE The cytologic, histologic, radiologic and clinical features of a DSRCT from a 17-year-old patient are presented. Although the initial diagnosis in this case was made on histology, recurrence was proven by fine needle aspiration biopsy (FNAB). CONCLUSION The presence of sheets or clusters of small round malignant cells, associated with shards of dense fibroconnective tissue, in FNAB should lead the cytologist to consider the diagnosis of DSRCT.

Transthoracic 2D echocardiographic guidance for percutaneous removal of a nonopaque intracardiac catheter fragment

A radiolucent fragment of a fractured central venous catheter embolized to the right heart resulting in life-threatening dysrhythmias in a middle-aged male patient who had undergone orthotopic liver transplantation I day earlier. The fragment was removed via the right transjugular route using sonographic guidance to entrap the fragment with a brightly echogenic snare. The technique described protects the caval anastomoses in the liver transplant recipient and overcomes the limitation of fluoroscopy in removing radiolucent bodies

Preclinical evaluation of an iodinated particulate contrast agent for use during angiography: work in progress.

PURPOSE To study the feasibility of using an iodinated particulate contrast agent, iodipamide ethyl ester (IDE), for angiography. MATERIALS AND METHODS IDE at doses of 40-100 mg of iodine per kilogram was diluted to a total volume of 5-20 mL and used for digital subtraction angiography in nine dogs under general anesthesia. Equivalent images were obtained by using water-soluble contrast medium (WSCM) for comparison (iohexol) in seven animals. All images were reviewed by blinded reviewers and graded subjectively on a five-point scale. RESULTS Angiographic studies of multiple vascular territories performed with IDE yielded images of slightly lower overall quality compared with images obtained with WSCM (P = .14, Mann-Whitney U test). Arterial phase images were subjectively superior with WSCM when compared with IDE (P < .0001, chi 2.) Depiction of the corresponding veins during the venous phase on the IDE angiograms was superior to that on WSCM angiograms in 12 of 21 cases, although this did not reach statistical significance (P > .05 chi 2). Images of the renal vein and portal vein achieved with IDE were graded as superior to those achieved with WSCM in eight of 10 reviews. CONCLUSION Angiography is feasible with IDE. Compared with WSCM, IDE produced images of lesser quality during the arterial phase, but of equal or superior quality in the venous phase depending on the vessel studied. Because it is excreted slowly in bile and is isotonic, it may prove useful in patients with renal insufficiency, diabetes, multiple myeloma, or severe coronary disease.

The Thoracic Aorta: Imaging in Health and Disease

The Normal Thoracic Aorta The thoracic aorta is the result of a succession of events relating to fusion of the paired primitive dorsal and ventral aortae and the persistence or regression of their connections to the paired arterial stlUctures of the six primitive branchial arches that develop in the embryonic stage. The thoracic aorta can be divided into five segments. The aortic root or bulb begins at the aortic valve, having three uniform cusps of equal size and shape. Each cusp subtends one of the three sinuses of Valsalva, named posterior or (noncoronary), left. The left coronary artery arises from the left sinus, whereas the right coronary artery arises from the right sinus. The sinus portion above the valve plane has a diameter of 3.6-3.9 cm. On a frontal chest radiography, this portion of the aorta is buried within the cardio-pericardial silhouette and is not visible. It is, however, readily distinguishable on aortography. The tubular portion begins above the sinuses at the sino-tubular junction with the ascending aorta, which is 4-5 cm long and of uniform diameter between 2.8-3.5 cm. Much of the ascending aorta is intrapericardial. On a frontal chest radiograph, the normal ascending aorta is not border forming. The transverse arch of the aorta is the remnant of the aortic sac proximally and the left fourth branchial arterial arch distally and courses posterolaterally from right to left in a parasagittal plane. It is approximately 5 cm long, 2.5-3 cm in diameter, and gives rise to the brachiocephalic or innominate artery, the left common carotid artery, and the left subclavian artery, in that order. The brachiocephalic artery branches further into the right subclavian artery and the right common carotid artery. Many variations of the branching pattern of the brachiocephalic vessels exist. On frontal chest radiography, the lateral margin of the left subclavian artery forms the superior left border of the mediastinum, and the lateral margin of the distal transverse arch is recognizable as the aortic knob. Occasionally, the superior intercostal vein appears as a nipple on the aortic knob on a frontal chest radiograph. The aortic isthmus is a distinct zone of narrowing beginning distal to the origin of the left subclavian artery and extending over a short variable distance. It is most apparent on aortography in the pediatric patient and disappears with age. It is probably the result of reduced flow in this region during fetal development, where the left ventricular outflow primarily serves the vessels of the head, neck, and upper extremities prOXimal to the isthmus, and the right ventricular outflow serves the descending thoracic aorta distal to the isthmus through shunting through the ductus arteriosus. A remnant of the infundibulum of the ductus arteriosus frequently can be seen even in adult aortae as the ductus bump along the anteromedial wall of the lesser curve of the aorta just distal to the left subclavian artery origin at the ligamentum arteriosum. Larger ones are called a ductus diverticulum. It is of prime importance to recognize this normal variant, especially in the patient who has suffered blunt chest trauma, because it can be mistaken for an aortic laceration. The descending thoracic aorta begins at the isthmus and courses distally slightly left of the vertebral column and approaches the midline at the aortic hiatus of the diaphragm. It has a diameter of 2.5-3 cm proXimally, or approximately two thirds the diameter of the ascending aorta and tapers distally to 2.4-2.7 cm diameter at the aortic hiatus. The descending thoracic aorta gives off from three to eight pairs of intercostal arteries, those on the left typically arising from the dorsal aspect of the aorta at the level of the vertebral pedicles. Although those on the right usually originate from the dorsal aspect of the aorta, the upper right intercostal arteries may arise from the right lateral or even the ventral surface of the descending thoracic aorta. The descending thoracic aorta also gives rise to the bronchial alteries. The most common pattern encountered is two left bronchial arteries and a single right intercostobronchial trunk. Although a large number of anatomic variation exists, each side usually has one or two bronchial arteries. The bronchial arteries typically arise from the ventral aspect of the descending thoracic aorta between T4 and T8, but can also arise from the undersurface or convexity of the aortic arch, the thyrocervical or costocervical tmnks and can derive collateral supply from many axillary and subclavian artery chest wall branches. It is important to be aware that radicular branches to the anterior spinal artery can arise in conjunction with intercostal or bronchial arteries, partiCUlarly if one is about to undertake embolization of these vessels. High quality, motion-free angiography with analog or digital subtraction is required if one is to recognize and avoid embolization of radiculomedullary feeders.