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R A Baum

Publications and source records attributed to R A Baum.

At least 37 records · Page 2Linked to original sources
PubMed2000

Diagnosis and treatment of inferior mesenteric arterial endoleaks after endovascular repair of abdominal aortic aneurysms.

PURPOSE: To review the incidence and repair of inferior mesenteric arterial (IMA) type II endoleaks after endovascular repair of abdominal aortic aneurysms. MATERIALS AND METHODS: Fifty patients who underwent endovascular repair of abdominal aortic aneurysms were examined. If an endoleak was identified at 30-day postoperative computed tomography, conventional arteriography was performed to identify and eliminate its source. After the exclusion of attachment site leaks, a catheter was placed selectively in the superior mesenteric artery (SMA). If retrograde filling of the IMA and aneurysm was identified, coil embolization was attempted through the SMA and middle colic artery. Intrasac pressures were measured at embolization. RESULTS: Eight of 50 patients (16%) had type II endoleaks that were attributed to retrograde flow in the IMA. Intrasac measurements demonstrated systemic pressure in six patients and one-half systemic pressure in two patients. The IMA was embolized through the SMA and left colic artery in seven patients and through the translumbar aorta in one patient. CONCLUSION: Retrograde flow in the IMA is responsible for many type II endoleaks. Systemic pressures are transmitted into the aneurysm sac from the IMA. The IMA can be embolized successfully with an SMA approach in most patients.

Anastomosis, Surgical↗
PubMed1999

Perigraft air, fever, and leukocytosis after endovascular repair of abdominal aortic aneurysms.

BACKGROUND: The postimplantation syndrome of fever and leukocytosis after endovascular repair of infrarenal aortic aneurysms has not been previously characterized and its etiology is not known. METHODS: We studied the first 12 patients who underwent successful endovascular repair of infrarenal aortic aneurysms with Dacron-covered stent-grafts, as part of an ongoing phase II clinical trial. Sepsis syndrome evaluations (physical examination, urinalysis, chest radiograph, urine cultures, and blood cultures) were performed for all patients with postoperative temperature (T) greater than 101.4 degrees F. Computed tomography scans of the abdomen were performed, as part of the clinical protocol, on postoperative days 2 and 30. RESULTS: Fever (T > 101.4 degrees F) was seen in 8 of 12 (67%) patients (P < 05). An additional 2 of 12 (17%) patients had low-grade fevers (100.3 degrees F, 100.6 degrees F). Only 2 of 12 (17%) patients remained afebrile postoperatively. Leukocytosis with counts over 11,000 white blood cells (WBC)/dL was observed in 7 of 12 (58%) patients (P < 05). Sepsis evaluations failed to identify any source of infection in 11 of 12 (97%) patients. Computed tomography scan evidence of perigraft air was noted in 8 of 12 (67%) patients. All patients were afebrile, had normal white blood cell counts, and were discharged within 1 week postoperatively. There has been no evidence of graft infection after 1 to 6 months of follow-up. CONCLUSIONS: Fever and leukocytosis after stent-graft repair of aortic aneurysms does not represent evidence of systemic or graft infection and is not clearly related to nonspecific causes of postoperative fever and leukocytosis. Moreover, the finding of early postoperative perigraft air is not necessarily an indication of graft infection even when concurrently present with fever and leukocytosis.

Air↗
PubMed1999

Chemoembolization of hepatocellular carcinoma with cisplatin, doxorubicin, mitomycin-C, ethiodol, and polyvinyl alcohol: prospective evaluation of response and survival in a U.S. population.

PURPOSE: To evaluate response and survival after hepatic chemoembolization with cisplatin, doxorubicin, mitomycin-C, Ethiodol, and polyvinyl alcohol in a U.S. population of patients with hepatocellular carcinoma. MATERIALS AND METHODS: Thirty-eight consecutive patients were treated: 35% stage I, 62% stage II, 3% stage III. Fifty-one percent had cirrhosis. Chemoembolization was performed at approximately monthly intervals for one to seven sessions (mean, 2.2). Pretreatment and posttreatment cross-sectional imaging and alpha-fetoprotein (AFP) levels were obtained prospectively 1 month after treatment and then every 3 months. Thirty-day response was calculated by means of the the World Health Organization/Eastern Cooperative Oncology Group criteria. RESULTS: One patient was lost to follow-up. In seven patients, lesions became resectable after chemoembolization. Among 13 evaluable patients with initially elevated AFP level, 70% had a partial biologic response (>50% decrease in AFP), 15% had a minor response (25-50% decrease), and the remaining 15% remained stable. Among 25 patients evaluable for morphologic response, 36% had a partial response, 32% had a minor response, and 32% remained stable. No patients had progression of disease while receiving therapy. The cumulative survival was 60% at 1 year, 41% at 2 years, and 16% at 3 years. Two patients developed progressive hepatic failure. Thirty-day mortality was 3% (one patient). CONCLUSION: These results compare favorably to published response and survival data for chemoembolization of advanced hepatocellular carcinoma from Asia and Europe.

Antibiotics, Antineoplastic↗
PubMed1999

Renal artery stenosis: evaluation with conventional angiography versus gadolinium-enhanced MR angiography.

PURPOSE: To evaluate the interobserver and intermodality variability of conventional angiography and gadolinium-enhanced magnetic resonance (MR) angiography in the assessment of renal artery stenosis. MATERIALS AND METHODS: Fifty-four patients underwent conventional angiography and gadolinium-enhanced three-dimensional gradient-echo MR angiography. Three angiographers blinded to each other's interpretations and the MR angiographic findings assessed the conventional angiograms for renal artery stenosis. Similarly, three blinded MR imagers evaluated the MR angiograms. RESULTS: Interobserver variability for the degree of renal artery stenosis in the 107 kidneys evaluated was not significantly different between the two modalities. The mean SD of the degree of stenosis was 6.9% at MR angiography versus 7.5% at conventional angiography (alpha < or = .05, P > .05). In 70 kidneys (65%), the average degree of stenosis reported by the readers for the two modalities differed by 10% or less. In 22 cases (21%), the degree of stenosis was overestimated with MR angiography by more than 10% relative to the results of conventional angiography. In 15 cases (14%), the degree of stenosis was underestimated with MR angiography by more than 10%. CONCLUSION: Gadolinium-enhanced MR angiography permits evaluation of renal artery stenosis with an interobserver variability comparable with that of conventional angiography.

Angiography↗
PubMed1998

Magnetic resonance angiography of lower-extremity arterial disease.

Improvements in vascular technique have expanded the treatment options for patients with severe occlusive peripheral vascular disease. The decision to perform a major revascularization procedure in patients who are often at high risk for cardiovascular morbidity and mortality depends on the risk-benefit ratio. Detailed and accurate vascular imaging is essential and evaluating the likelihood of a successful revascularization with subsequent limb salvage. Although contrast angiography has been the time-honored reference standard imaging technique, the method is an invasive procedure with limitations and risks. MRA is a new, noninvasive vascular imaging technique that may now be added to the imaging options with the potential for improved sensitivity for finding patent runoff vessels, avoidance of morbidity, and cost equivalent to that of conventional contrast angiography. Magnetic resonance angiography is a rapidly developing and exciting new vascular imaging technique. As with any new technique, it is imperative that individual centers validate their MRA results and interpretations against the time-honored standard, which continues to be contrast arteriography. Several studies now indicate that MRA can be a cost-effective outpatient imaging technique sufficient for planning and successfully performing peripheral bypass procedures. As developments in hardware, software, and non-nephrotoxic contrast agents continue to increase, applicability of MRA in vascular surgery will continue to expand. Predictably, MRA will have a major role in the future of vascular imaging, and it is likely to supplant the need for conventional contrast angiography in the majority of patients.

Angiography, Digital Subtraction↗
PubMed1998

Endovascular surgery based solely on noninvasive preprocedural imaging.

PURPOSE: Conventional pre-endovascular procedural evaluation uses both noninvasive testing and diagnostic arteriography. Diagnostic and therapeutic procedures often must be performed separately because of concerns about excessive contrast administration or inappropriate location of vascular access for the interventional procedure. We wanted to determine if patients could successfully undergo endovascular procedures based on noninvasive modalities alone. METHODS: One hundred nineteen consecutive patients requiring intervention for lower-extremity ischemia were evaluated by means of physical examinations and segmental pressure measurements. Patients then underwent magnetic resonance angiography (MRA) to image native vessels or duplex scanning for failing bypass grafts. Suitable patients underwent endovascular procedures with "road map" arteriography, which was compared with preoperative duplex scanning or MRA findings. Costs of the conventional and noninvasive approaches were compared, on the basis of estimated hospital cost schedule. RESULTS: Sixty consecutive endovascular procedures were performed in 56 patients (105 lesions angioplastied), either alone (30, 50%) or in combination (30, 50%) with another vascular reconstruction. Completely noninvasive evaluation was accomplished in 43 procedures (72%), either by means of duplex scanning (11, 18%) or MRA (32, 53%). Conventional arteriography (CA) was required in 2 patients (3%) because of MRA contraindications and in 1 patient because of complex previous arterial reconstruction. Fourteen patients had earlier CAs. The findings of the noninvasive modalities were confirmed in every case by means of intraoperative arteriography, and no additional lesions were revealed (no false positive or negative studies). After endovascular interventions, the mean patient ankle-brachial index (ABI) improved from 0.64 +/- 0.03 to 0.81 +/- 0.03 (P <.001) and the mean limb-status category improved from 3.4 +/- 0.2 to 0.8 +/- 0.2 (P <.001). There were 4 initial technical failures (7%), 1 morbidity (1%), and no mortalities. The noninvasive approach was less costly than if preprocedural diagnostic CA had been used, allowing $551 saved for each duplex scanning case and $235 saved for each MRA case. If the cost of a short-stay unit after a diagnostic arteriogram was included, the savings were greater: $695 saved for each duplex scanning case and $379 saved for each MRA case. CONCLUSION: Endovascular procedures can be performed based on preprocedural noninvasive modalities alone. For patients requiring endovascular procedures, knowledge of the arterial anatomy before obtaining arterial access avoids the need for additional punctures or sessions (eg, antegrade puncture for femoral angioplasty after retrograde puncture for the diagnostic arteriogram). This approach is less costly than performing preprocedural diagnostic arteriography and avoids the hazards of arterial puncture and nephrotoxic contrast agents.

Aged↗
PubMed1998

Direct percutaneous jejunostomy: techniques and applications--ten years experience.

PURPOSE: To present 10 years experience with direct fluoroscopically guided percutaneous jejunostomy. MATERIALS AND METHODS: Percutaneous jejunostomy was performed in 62 patients, most of whom had undergone major abdominal surgery. A new or replacement jejunostomy was created for alimentation in 20 and 21 patients, respectively. Jejunostomy was performed for interventional procedures of the bile ducts or intestine in 13 patients and for retrograde gastroesophageal drainage in eight. The distended jejunum was accessed with a 21-gauge needle, immobilized with a gastric anchor, and catheterized with a 10-14-F locking loop drain. RESULTS: The technical success rate was 19 of 20 (95%) for new feeding jejunostomy and 17 of 21 (81%) for replacement feeding jejunostomy. Jejunostomy facilitated drainage, dilation, stone extraction, and recanalization in the bile ducts or intestine in all 13 patients. Retrograde jejunoesophagogastrostomy suction effectively replaced painful nasogastric suction in all eight patients. Two patients who underwent replacement jejunostomy required laparotomy for possible leakage; there was no important procedure-related morbidity and no procedure-related mortality. CONCLUSION: The technical success and complication rates of feeding percutaneous jejunostomy compare favorably with those of surgery or endoscopy. Percutaneous jejunostomy is a useful and underused approach to managing bowel and biliary obstruction.

Adult↗
PubMed1996

Safety of decreasing bedrest after coronary angiography.

This study was designed to assess the safety of allowing patients to ambulate after 2 hr of bedrest following coronary angiography. A total of 205 patients were randomized to either 2 or 4 hr of bedrest following hemostasis after angiography utilizing five, six, or seven French catheters. The primary endpoint was defined as bleeding requiring recompression and additional bedrest. No significant difference was demonstrated overall between the two groups with respect to rebleeding or hematoma formation when the angiogram was performed using five or six French catheters. However, the use of seven French catheters resulted in a significantly higher rebleeding rate in the 2-hr group compared to the 4-hr population. The findings of this study suggest that 2 hr of bedrest following angiography utilizing five or six French catheters is adequate to obtain hemostasis safely in the majority of patients, whereas 4 hr is suggested when seven French catheters are utilized.

Adult↗
PubMed1996

The fate of bypass grafts to angiographically occult runoff vessels detected by magnetic resonance angiography.

PURPOSE: Magnetic resonance angiography (MRA) is a noninvasive vascular imaging technique that is more sensitive than contrast arteriography (CA) for the detection of patent distal runoff vessels. This technique has facilitated performance of MRA-directed bypass procedures for patients who were believed not to be bypass candidates because of the absence of a suitable target vessel on the preoperative CA. The fate of bypasses to these angiographically occult runoff vessels is unknown, however, and it has been proposed that patients with angiographically occult runoff may have aggressive occlusive disease, rendering bypass procedures ultimately futile. METHODS: Between April 1992 and February 1995, 212 autogenous vein infrageniculate bypasses were performed for limb-salvage indications, 22 (12%) to angiographically occult runoff vessels. Results of bypasses performed to angiographically occult vessels were compared with those of bypasses to CA-detected runoff vessels. Life-table analysis of graft-patency and limb-salvage rates was performed. RESULTS: The accuracy of the MRA-predicted patency of angiographically occult vessels was confirmed in every case by the operative findings. Life-table analysis revealed no significant difference in primary graft patency (p > 0.05) or limb-salvage (p > 0.05) rates between patients with bypasses to runoff vessels seen by MRA alone. At 35 months after surgery, the primary graft patency rate was 68% for bypasses to CA-detected vessel bypass and 67% for MRA-detected vessels. The limb salvage rate was 83% for CA-detected vessel bypass patients and 78% for patients with angiographically occult runoff. CONCLUSIONS: MRA can accurately identify patent runoff vessels not visualized by CA. Results of bypasses performed to angiographically occult runoff vessels are similar to those of bypasses performed to vessels detected by CA. MRA should be performed in patients in whom CA fails to reveal runoff vessels suitable for use in a limb-salvage procedure. The greater sensitivity of MRA may facilitate successful bypass surgery and improve the overall limb-salvage rate.

Aged↗
PubMed1996

Temporary use of a Bird's Nest filter during iliocaval thrombolysis.

A jugular Bird's Nest filter (Cook, Bloomington, Ind) was partially deployed in the suprarenal cava for prophylaxis to prevent pulmonary embolism in a young woman with phlegmasia cerulea dolens. It was effective in capturing large emboli during thrombolysis of a loose iliocaval thrombus. It was safely removed 6 1/2 hours later, after lysis of most retained filter clots.

Adult↗
PubMed1995

Multicenter trial to evaluate vascular magnetic resonance angiography of the lower extremity. American College of Radiology Rapid Technology Assessment Group.

OBJECTIVES: To assess the value of magnetic resonance angiography (MRA) in presurgical evaluation of patients with severe lower limb atherosclerotic occlusive disease and to assess the feasibility of rapidly conducting rigorous technology assessment. DESIGN: Blinded, prospective study of consecutive patients with signs or symptoms of severe infrainguinal peripheral vascular disease who were candidates for percutaneous or surgical intervention. Using both descriptive statistics and multivariate logistic analyses, MRA was compared with contrast arteriography (CA) (the current technique) for imaging 15 arterial segments of the leg and foot. Intraoperative contrast angiography was the "gold" standard. Also studied was the effect of adding MRA to the information used in planning treatment. SETTING: Six US hospitals, one a community hospital. PATIENTS: A total of 155; 84% with either rest pain or tissue loss. RESULTS: Sensitivity in distinguishing patent segments from completely occluded segments was 83% for CA and 85% for MRA; both had 81% specificity. For distinguishing near-normal segments (suitable as bypass graft termini), CA was less sensitive than MRA (77% vs 82%), but more specific (92% vs 84%). After adjusting for same-reader effects, odds of correctly distinguishing patent segments were 1.6 times as great for MRA as for CA (P < .01); for distinguishing near-normal segments, the odds for CA were 1.5 times as great as for MRA (P < .05). The addition of MRA changed the treatment plan in 13% of patients; in 86% of these cases, the surgery actually performed indicated that the MRA-inclusive plan was superior. CONCLUSIONS: Individually, MRA and CA are approximately equivalent in diagnostic accuracy. The addition of MRA to treatment plans based only on CA and other diagnostic information clearly improves the plans. Completed in 15 months (as planned), our study demonstrates the feasibility of conducting rigorous technology assessment rapidly enough to be timely even in fields in which diagnostic and treatment techniques are rapidly changing.

Adult↗
PubMed1995

Magnetic resonance angiography of the distal lower extremity.

OBJECTIVE: To assess magnetic resonance angiography (MRA) for demonstration of arterial patency in the ankle and foot of patients with peripheral vascular disease. METHODS: Peripheral MRA of the ankle and foot was performed on 34 limbs of 31 insulin-dependent diabetics. 2-D time-of-flight MRA (TR 33 ms/TE 7.7 ms/inferior saturation band) was performed with 16 cm field of view. Pre- or intra-operative angiographic correlation was available in all cases. RESULTS: In 24 limbs MRA was compared to conventional angiography. MRA showed more patient run-off vessel segments (120) than angiography (100). In 10 limbs MRA was compared to intraoperative angiography and for the detection of patent vessel segments showed a sensitivity of 87.5% (42/48) with a 95% confidence interval of 75% to 95% and a specificity of 95% (38/40) with a 95% confidence interval of 83% to 99%. Pitfalls included difficulty in visualizing flow at the bifurcation of the peroneal artery, in the plantar arch and retrograde flow in the lateral plantar artery. CONCLUSIONS: MRA is sensitive for the detection of patent arteries in the ankle and foot but artefacts may cause overdiagnosis of focal stenoses or occlusions.

Aged↗
PubMed1995

Cost-effectiveness of MR angiography in cases of limb-threatening peripheral vascular disease.

PURPOSE: To evaluate the cost-effectiveness of magnetic resonance (MR) angiography in the preoperative planning of treatment in patients with limb-threatening peripheral vascular disease (PVD). MATERIALS AND METHODS: A decision model was developed to study the effects of MR angiography on the outcome and cost of treatment. The authors calculated the incremental cost per quality-adjusted life-years gained (ie, cost-effectiveness ratio) when conventional angiography was replaced or supplemented with MR angiography. Previously reported data regarding the accuracies of MR and conventional angiography were used in the analysis. RESULTS: The cost-effectiveness ratio of MR angiography ranged from negative (cost-reducing) values to $78,000. For the base case in which the sensitivity and specificity of MR angiography for the evaluation of inflow vessels were 92% and 88% and those of conventional angiography were 97% and 97%, respectively, the cost-effectiveness ratio was $25,895. CONCLUSION: MR angiography may be a cost-effective alternative to conventional angiography in patients with limb-threatening PVD if its accuracy for the inflow evaluation reaches certain thresholds. Further prospective investigation is warranted.

Angiography↗
PubMed1995

Intentional reversible thrombosis of transjugular intrahepatic portosystemic shunts.

PURPOSE: To assess whether balloon occlusion of a transjugular intrahepatic portosystemic shunt (TIPS) will allow permanent yet reversible shunt thrombosis. MATERIALS AND METHODS: A balloon catheter was inflated in the midportion of the TIPS in two women with severe, uncontrollable encephalopathy or liver failure (aged 42 and 65 years, respectively) to allow occlusive thrombus to develop below the balloon. RESULTS: Balloon occlusion led to rapid TIPS thrombosis, which was readily reversible. CONCLUSION: Balloon thrombosis is a simple technique for complete occlusion of a TIPS. This technique may also be useful for occlusion of surgical mesocaval H-graft shunts or dialysis access shunts.

Adult↗
PubMed1994

Preliminary experience with magnetic resonance venography: comparison with findings at surgical exploration.

While conventional magnetic resonance imaging has been described for the evaluation of the venous system, we have recently developed the technique of magnetic resonance venography (MRV), which generates three-dimensional projection venograms. Our purpose was to determine if MRV reliably images the venous system by comparison with findings at surgical exploration. Thirteen of fourteen consecutive patients undergoing bypass surgery (26 limbs) were studied by 2D time-of-flight MRV preoperatively from the inguinal ligament to the ankle bilaterally. The average examination time was 50 min. The size and quality of each saphenous vein were recorded at the saphenofemoral junction, mid-thigh, knee, mid-calf, and malleolus. Intraoperatively the quality and size of each vein were measured in situ and when distended by saline. Twelve veins were of good quality. MRV predicted this in every case. One vein, found to be recanalized, had an abnormally thick wall noted on MRV. MRV measurements of average vein size were intermediate between that of the in situ and distended vein and correlated most closely with the distended vein (R = 0.74, P < 0.001). The superficial and deep femoral veins and lesser saphenous veins were routinely visualized by MRV; thus a complete map of all available vein was obtained by a single study. It is concluded that MRV is an accurate method of venous imaging as confirmed by findings at operative exploration. This new technique holds promise as a noninvasive method for evaluation of the venous system and warrants further investigation.

Coronary Artery Bypass↗
PubMed1994

Peripheral vascular surgery with magnetic resonance angiography as the sole preoperative imaging modality.

PURPOSE: Magnetic resonance angiography (MRA) is a developing technique that provides arteriograms without the risks associated with iodinated contrast and arterial puncture or the expense of hospitalization. Prior reports have demonstrated the accuracy of peripheral vessel MRA for evaluation of the aorta through pedal vessels. This study sought to determine whether vascular reconstructions could be planned and accomplished on the basis of MRA alone. METHODS: Eighty consecutive candidates for bypass with ischemic rest pain or tissue loss were studied with preoperative outpatient MRA of the juxtarenal aorta through the foot. Confirmation of MRA findings was provided by intraoperative intraarterial pressure measurements for proximal vessels and postbypass arteriography for the runoff. Life-table analysis of graft patency and limb salvage was performed. RESULTS: Two patients could not tolerate MRA and required contrast arteriography, but all others underwent reconstructive procedures on the basis of MRA alone (11 aortobifemoral, 67 infrainguinal). Intraoperative findings regarding suitability of inflow and outflow vessels confirmed the accuracy of the MRAs in every case. MRA indicated that none of the patients undergoing infrainguinal bypass had significant inflow occlusive disease, and this was confirmed at operation with pressure measurements of inflow vessels that were always within 10 mm Hg (peak systolic) of systemic pressure. The results of intraoperative completion arteriography and preoperative MRAs were identical for all but two patients who had minor discrepancies. All aortobifemoral reconstructions remained patent, and all limbs remained intact. The infrainguinal reconstructions had an 84% limb salvage rate and 78% primary graft patency rate at 21 months. Comparison of charges for patients undergoing preoperative MRA versus contrast angiography showed a cost savings of $1288 for each patient treated with preoperative MRA alone. CONCLUSIONS: MRA is a noninvasive, cost-effective outpatient imaging technique that, if properly performed and interpreted, is sufficient for planning peripheral bypass procedures. Its use may supplant contrast arteriography in many patients.

Adult↗