John A. Kaufman

Clinical outcome of internal iliac artery occlusions during endovascular treatment of aortoiliac aneurysmal diseases.

PURPOSEnTo determine the clinical outcome of hypogastric artery occlusion in patients who underwent endovascular treatment of aortoiliac aneurysmal disease.nnnMATERIAL AND METHODSnFrom January 1994 to March 1998, 94 patients underwent endovascular treatment of aneurysmal diseases involving the infra-abdominal aorta or iliac arteries. Preoperative and intraoperative radiologic data were reviewed. Discharge summaries, clinic visits, and phone calls formed the basis for clinical follow-up, with a mean follow-up period of 7.3 months (range, 1-24 months).nnnRESULTSnBecause of the anatomy of the aneurysms, 28 patients required occlusion of one or more hypogastric arteries. One of the 28 patients died of unrelated causes before follow-up. Seven (26%) of the remaining 27 patients developed symptoms attributable to the hypogastric artery occlusions. Five patients developed new buttock or thigh claudication; of these five patients, three with initially mild symptoms noted complete or near complete resolution of symptoms upon follow-up. One patient with originally significant claudication at 2-year follow-up noted near resolution of symptoms. The other patient with severe pain did not improve significantly on final 1-year follow-up before his death (of unrelated causes). Other clinical complications were worsening sexual function in one patient and a nonhealing sacral decubitus ulcer that developed in a debilitated patient in the postoperative setting, which required surgery. No bowel ischemia was observed.nnnCONCLUSIONnWhen treating aortoiliac aneurysmal disease through an endovascular approach, the occlusion of internal iliac artery is often necessary but carries with it a small but finite chance of morbidity.

HELICAL (SPIRAL) CT IN THE EVALUATION OF EMERGENT THORACIC AORTIC SYNDROMES: Traumatic Aortic Rupture, Aortic Aneurysm, Aortic Dissection, Intramural Hematoma, and Penetrating Atherosclerotic Ulcer

For the near future, CT will play the critical and dominant role in the evaluation of patients presenting with emergent aortic syndromes. Its convenience, accuracy, and utility in the rapid evaluation of not just the aorta, but the entire thorax, make it ideally suited for use in emergency settings. Further benefits are likely to be realized in speed and resolution with multislice CT, although it is as yet not widely available.

Migration of Central Venous Catheters: Implications for Initial Catheter Tip Positioning

PURPOSEnTo evaluate the change in position of chest wall central venous access catheters (CVACs) after placement. Complication rates associated with catheter tip position were reviewed.nnnPATIENTS AND METHODSnFifty patients (36 women, 14 men) with chest wall CVACs placed in the angiography suite were studied. Catheter migration was calculated as the difference between the carina-catheter tip measurements on immediate supine and upright postprocedure (within 24 hours) chest radiographs. Catheter-related complication data were gathered via telephone interview and review of the medical records.nnnRESULTSnPeripheral catheter migration occurred in 49 of 50 patients (average, 3.2 cm +/- 1.8); central catheter migration occurred in one of 50 patients (3.9 cm). Catheter type was the only significant factor that affected the amount of migration; side of insertion or the patients gender were not significant. Catheter malfunction and symptomatic upper extremity venous thrombosis rates tended to be lower in patients with right atrial versus superior vena cava catheters (18% vs 34%), but differences were not significant (P = .202).nnnCONCLUSIONnCatheter migration after chest wall CVAC placement is a common event. The catheter tip should be initially positioned approximately 3-4 cm more centrally than the desired final position. Further study is necessary of catheter-related complication rates relative to the final position of the catheter tip.

Magnetic resonance angiography in the management of lower extremity arterial occlusive disease: a prospective study.

PURPOSEnWe conducted a prospective study to clarify the clinical utility of magnetic resonance angiography (MRA) in the treatment of patients with lower extremity arterial occlusive disease.nnnMETHODSnDuring the interval of September 1993 through March 1995, 79 patients (43% claudicants, 57% limb-threatening ischemia) were studied with both MRA and contrast arteriography (ANGIO) and underwent intervention with either balloon angioplasty (9%), surgical inflow (28%), or outflow (63%) procedures. MRA and ANGIO were interpreted by separate blinded vascular radiologists, and arterial segments from the pelvis to the foot were graded as normal or with increasing degrees of mild (25% to 50%), moderate (51% to 75%), or severe (75% to 99%) stenosis or occlusion. Treatment plans were formulated by the attending surgeon and were based initially on hemodynamic, clinical, and MRA data and thereafter with ANGIO. Additional study surgeons formulated independent and specific treatment plans based on MRA or ANGIO alone. Indexes of agreement (beyond chance) for arterial segments depicted by MRA and ANGIO were assessed (kappa value), and treatment plans formulated were compared (chi-square).nnnRESULTSnPrecise agreement (%) and the percent of major discrepancies (segment classified as normal/mild stenosis on one study and severe stenosis/occlusion on the other) between MRA and ANGIO for respective arterial segments was as follows: common and external iliacs (n = 256) 77/3.5; superficial femoral and above-knee popliteal (n = 255) 73/6.7; below-knee popliteal (n = 131) 84/3.8; infrapopliteal runoff vessels (n = 864) 74/12.4; pedal vessels (n = 111) 69/19.8 Kappa values indicated moderate agreement (between MRA and ANGIO) beyond chance for all arterial segments. Treatment plans formulated by the attending surgeon, the MRA surgeon, and the ANGIO surgeon agreed in more than 85% of cases. Inability of MRA to assess the significance of inflow disease and inadequate detail of tibial/pedal vessels were the principal deficiencies of MRA in those cases where it was considered an inadequate examination.nnnCONCLUSIONnThese findings suggest MRA and ANGIO are nearly equivalent examinations in the demonstration of infrainguinal vascular anatomy. MRA is an adequate preoperative imaging study (and may replace ANGIO), particularly in those circumstances when the risk of ANGIO is increased or when clinical and hemodynamic evaluation predict the likelihood of straightforward aortofemoral or femoral-popliteal reconstruction.

The imperative for medical simulation

The practice of medicine has, for millennia, relied upon a master-apprentice system of learning, with patients providing the necessary anatomy from which one learns how to perform surgery and other procedures. The advent of high-power computing and real-time graphics representations allows medicine to advance beyond this traditional methods of teaching and to begin to educate physicians without putting patients at risk. With innovative haptics interface devices, computer-based training will enable novice physicians to learn procedures that have been developed since their training was completed. Specialty boards and credentialing organizations will, for the first, time, have metrics upon which to base the decisions regarding who is qualified to practice medicine, and both sides of the learning curve, the acquisition of skills and their deterioration, will be discovered. The paper presents the concepts, challenges, and visions of the authors, both of whom have been actively developing simulation for the specialty of interventional radiology. It includes expectations for the future of simulation in other procedural specialties.

The potential for lower extermity revascularization without contrast arteriography: Experience with magnetic resonance angiography

Abstract Purpose:xa0We report an initial experience with 24 patients studied between March 1990 and April 1992 with magnetic resonance angiography (MRA) for lower extremity occlusive disease. Methods:xa0All patients underwent vascular intervention with either balloon angioplasty or bypass grafting, and in six patients this intervention was based on MRA findings alone. Eighteen patients were studied with both MRA and contrast arteriography, and there was observed agreement between the two studies in 98% of all arterial segments examined. Results:xa0Agreement between MRA and contrast arteriography was uniform for arterial segments below the inguinal ligament. Intraoperative findings and favorable early results of seven bypass grafts performed in six patients after MRA alone suggested this was a valid approach for patients at prohibitive risk of complications from contrast arteriography. Conclusions:xa0Magnetic resonance angiography is accurate in demonstrating relevant anatomy in peripheral arterial occlusive disease and in selected patients may eliminate the need for contrast arteriography before lower extremity revascularization. (J V ASC S URG 1993;17:1050-7.)

Anatomical Observations on the Renal Veins and Inferior Vena Cava at Magnetic Resonance Angiography

PurposeTo describe the renal vein and inferior vena cava (IVC) anatomy found at abdominal magnetic resonance (MR) angiography.MethodsGadolinium-enhanced, three-dimensional, time-of-flight MR angiograms of 150 patients were evaluated for the number and configuration of the renal veins, and the number, configuration, and dimensions of the IVC. Data were analyzed with the Students ttest.ResultsRetroaortic left renal veins were found in 7% of patients, circumaortic left renal veins in 5%, multiple right renal veins in 8%, and duplicated IVCs in 0.7%. The length of the infrarenal IVC averaged 94 mm in females and 110 mm in males (p<0.00001). The length of the infrarenal IVC in patients with circumaortic and retroaortic left renal veins averaged 76 mm and 46 mm, respectively. The mean maximal caval diameter was 23.5±4 mm. No megacavae (diameter of the mid-IVC > 28 mm) were identified.ConclusionVariant renal vein and IVC anatomy can be identified at MR angiography.

Weekly Prophylactic Urokinase Instillation in Tunneled Central Venous Access Devices

PURPOSEnTo determine the safety and efficacy of weekly prophylactic urokinase therapy in tunneled central venous access devices (VADs).nnnMATERIALS AND METHODSnA prospective, randomized study was performed in 105 patients who underwent tunneled VAD placement between March 1997 and April 1998. The patients were randomized to receive either twice-daily heparin flushes (14 heparin flushes per week; group A, n = 52) or twice-daily heparin flushes with once-weekly urokinase (UK) instillation (13 heparin flushes, one UK flush per week; group B, n = 53). Patients were followed up by examination and/or interview at 1, 3, and 6 months for signs and symptoms of delayed catheter-related complications.nnnRESULTSnThe total number of indwelling catheter-days was similar between groups (5,450 in group A, 5,276 in group B). The total number of infectious complications and fibrin sheaths formed was greater for group A (n = 11; 21.1%) than group B (n = 3; 5.7%) (P = .02). There were no side effects noted from the prophylactic UK administrations.nnnCONCLUSIONnProphylactic UK is advantageous in preventing delayed catheter-related complications.

Time of flight renal MR angiography: Utility in patients with renal insufficiency

We studied the renal arteries prospectively in 16 patients with renal insufficiency using a combination of two-dimensional and three-dimensional time of flight magnetic resonance angiography (MRA). Results were compared with conventional angiography. All renal arteries were identified by MRA. Accuracy for classifying renal arteries into patent, moderately (30-70%) stenotic, severely (> 70%) stenotic, or occluded was 91%. With regard to the presence or absence of severe occlusive disease (> 70% stenosis or occlusion) the sensitivity was 100%, with a specificity of 93%.

Gadopentetate Dimeglumine: A Possible Alternative Contrast Agent for Ct Angiography of the Aorta

We report the use of a gadolinium chelate for limited CT angiography of the aorta in a patient in whom iodinated contrast agent was contraindicated and who had undergone nondiagnostic MRI.