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Suresh Vedantham

Publications and source records attributed to Suresh Vedantham.

16 recordsLinked to original sources
PubMed2005

Power injection of microcatheters: an in vitro comparison.

PURPOSE: To determine the tolerance of 0.021-inch and 0.027-inch microcatheters to power injection in an in vitro flow model. MATERIALS AND METHODS: Twenty-four microcatheters (0.021-inch, n = 13; 0.027-inch, n = 11) were injected with iothalamate meglumine through a flow model with use of a power injector and high-pressure tubing. Catheters used included Rebar (0.021-inch, n = 4; 0.027-inch, n = 4), Transit (0.021-inch, n = 3; 0.027-inch, n = 3), Renegade (0.021-inch, n = 4; 0.027-inch, n = 4), and Renegade STC-18 (0.021-inch, n = 2) models. Through the 0.021-inch microcatheters, 5-second injections were performed at an initial rate of 0.7 mL/sec. Injection rates were increased by 0.5 mL/sec and the process was repeated until the pressure approached 1,000 psi or catheter breakage occurred. A similar process was repeated for the 0.027-inch catheters starting at a rate of 3.4 mL/sec. RESULTS: The 0.021-inch catheters were injected 303 times and the 0.027-inch catheters were injected 210 times. Three catheter failures occurred, with all breaks occurring at pressures greater than manufacturer recommendations. The 0.027-inch catheters as a group tolerated significantly higher injection rates than the 0.021-inch catheters. Of the 0.021-inch catheters, the STC-18 also provided superior maximum flow and volume compared with the Renegade catheter. The Rebar catheter tolerated significantly lower maximum injection rates and volumes than the other 0.027-inch catheters. CONCLUSIONS: The majority of microcatheters can be power-injected in vitro at pressures far greater than manufacturer recommendations. When fractures occur, they are near the hub of the catheter. Significantly greater rates of injection are possible through 0.027-inch catheters.

Catheterization↗
PubMed2004

Pharmacomechanical thrombolysis and early stent placement for iliofemoral deep vein thrombosis.

PURPOSE: To evaluate an approach to the treatment of iliofemoral deep vein thrombosis (DVT) that included pharmacomechanical catheter-directed thrombolysis with reteplase and the Helix mechanical thrombectomy device, followed by early stent placement. MATERIALS AND METHODS: During 3-year period, 23 symptomatic limbs in 18 patients with iliofemoral DVT were treated with reteplase catheter-directed thrombolysis. After an initial infusion of 8 to 16 hours, any residual acute thrombus over a long segment (> 10 cm) was treated by maceration with use of the Helix thrombectomy device. Residual short-segment (< 10 cm) iliac vein thrombus and/or stenosis were treated with stent placement. Technical success, clinical success, complications, thrombolytic infusion time, total thrombolytic agent dose, fibrinogen level changes, and late limb status were retrospectively analyzed. RESULTS: Technical success was achieved in 23 of 23 limbs (100%). Clinical success was achieved in 22 of 23 limbs (96%). Complete or partial thrombolysis was observed in 19 of 23 limbs (83%). Major bleeding was observed in one patient (6%) and necessitated blood transfusion. Mean per-limb thrombolytic infusion time and total dose were 19.6 hours +/- 8.1 and 13.8 U +/- 5.3 reteplase, respectively. Mean serum fibrinogen nadir and percentage drop in serum fibrinogen were 282 mg/dL +/- 167 and 47% +/- 24%, respectively. Late (mean, 19.8 +/- 11.6 months) modified Venous Disability Scores were 0 (none) for six limbs, 1 (mild) for 10 limbs, 2 (moderate) for two limbs, and 3 (severe) for no limbs. CONCLUSION: In a preliminary experience, pharmacomechanical catheter-directed iliofemoral DVT thrombolysis with early stent placement was safe and effective.

Adolescent↗
PubMed2003

Percutaneous management of ischemic complications in patients with type-B aortic dissection.

PURPOSE: To review our experience with the use of percutaneous methods to manage the ischemic complications of type-B aortic dissection. MATERIALS AND METHODS: Retrospective review of our interventional radiology database identified 11 patients with acute type-B aortic dissection who underwent 13 endovascular procedures to attempt revascularization of 23 ischemic vascular territories (four mesenteric, 11 renal, eight lower extremities). Percutaneous interventions included balloon fenestration (four patients), aortic true lumen stent placement (three patients), and branch vessel stent placement (eight patients). RESULTS: Successful initial reperfusion of 21 of 23 vascular territories (91%) was achieved with use of percutaneous methods alone, with no 30-day mortality, in-hospital mortality, or paraplegia. One additional patient underwent successful initial treatment with use of a combined interventional/surgical approach to reperfuse an ischemic limb. One patient developed acute thrombosis of a dissected renal artery during stent placement. Increased aortic true lumen collapse later resulted in further ischemia in two patients. During follow-up (mean, 16 mo), no patient has had evidence of false lumen enlargement or late recurrent ischemia. CONCLUSION: Endovascular methods offer a less-morbid nonsurgical treatment alternative for patients with acute complicated type-B aortic dissection.

Aortic Dissection↗
PubMed2003

Gadolinium, carbon dioxide, and iodinated contrast material for planning inferior vena cava filter placement: a prospective trial.

PURPOSE: To prospectively compare the diagnostic accuracy of CO(2) and gadolinium to iodinated contrast material for inferior vena cavography before inferior vena cava (IVC) filter placement. MATERIALS AND METHODS: Forty patients underwent injection of iodinated contrast material, CO(2), and gadolinium. Iodinated contrast material was used as the standard. Caval diameter was determined with calibrated software. Three readers blinded to contrast agent used measured the distance from the superior image border to the inferior margin of the renal veins and from the inferior image border to the iliac bifurcation. The measurements with CO(2) and gadolinium were compared to those with iodinated contrast material to obtain the interobserver and intraobserver variability. The presence or absence of caval thrombus and variant anatomy was noted. The same readers reexamined 12 studies in a separate session to determine intraobserver variability and correlation. RESULTS: Caval diameter differed by 0.4 mm or less for all three agents. Measurements with all agents were within 2 mm of each other for all patients. Gadolinium and CO(2) were not significantly different from one another in measuring caval diameter. At the initial reading, compared with iodinated contrast material, gadolinium had greater mean interobserver error in measuring the distance to the iliac bifurcation and both renal veins (range, 1.6-1.8 mm) than CO(2) (range, 0.2-1.4 mm). This finding, although statistically significant for gadolinium (P <.05), was of doubtful clinical relevance. Interobserver correlation was significantly worse for CO(2) at the levels of the iliac bifurcation (P =.02) and right renal vein (P =.008). Interobserver correlation for gadolinium was similar to that for iodinated contrast material at all levels. At repeat reading, there was significantly inferior intraobserver correlation with use of CO(2) for both renal veins (P <.05) compared to iodinated contrast material and for the left renal vein (P <.05) compared to gadolinium. Gadolinium identified three of three renal vein anomalies identified with iodinated contrast material whereas CO(2) localized one of three. CONCLUSION: CO(2) and gadolinium had limitations when compared with iodinated contrast material. Gadolinium provided superior consistency in identifying relevant landmarks for filter placement. CO(2) demonstrated significantly greater mean correlative error than gadolinium at initial and repeat readings.

Aged↗
PubMed2003

Endovascular recanalization of the thrombosed filter-bearing inferior vena cava.

PURPOSE: To evaluate the authors' preliminary experience with use of endovascular methods to treat inferior vena cava (IVC) thrombosis in patients with IVC filters. MATERIALS AND METHODS: Catheter-directed thrombolysis, balloon maceration, mechanical thrombectomy, and stent placement were used to treat 10 patients with thrombosis of filter-bearing IVCs causing symptoms in 18 limbs. Procedural challenges, technical and clinical success, complications, postprocedural filter status, and postprocedural pulmonary embolism (PE) prophylaxis were monitored. RESULTS: Technical and clinical success were achieved in 15 of 18 (83%) and 14 of 18 symptomatic limbs (78%), respectively. Major bleeding (muscular hematoma) occurred in one patient (10%). Postprocedural PE prophylaxis included anticoagulation (n = 8) and placement of a new filter into a newly placed Wallstent (n = 1). During clinical follow-up, no clinically detectable PE was observed. Data pertaining to late limb status were available at a median of 19 months (range 1-46 months) follow-up in seven patients: three patients were asymptomatic, two patients had ambulatory edema only, one patient had constant mild edema, and one patient had constant severe edema. Postprocedural filter stability was radiographically documented at a median of 255 days (range, 4-1021 d) of follow-up. CONCLUSION: Endovascular recanalization of the occluded IVC is feasible even in the presence of an IVC filter.

Adult↗
PubMed2002

Endovascular repair of abdominal aortic aneurysms in women after FDA approval: results, complications, and limitations.

Women account for approximately 25% of patients with AAAs, but unfortunately, only 8-10% of patients considered candidates for endovascular treatment during prospective trials were women. We reviewed our experience with open surgical and endovascular techniques before and after the FDA approval of the Ancure and AneuRx devices to evaluate our results and the role of endovascular treatment of AAAs in women. From January 1999 to August 2000, 269 patients underwent elective repair of their AAAs at our institution. The 20-month period was divided into the 10 months before and after the FDA approval of the endovascular devices for comparison. In the initial time period, 75 patients (62 men and 13 women) underwent repair with 40% undergoing endovascular repair. In the 10 months after FDA approval, 194 patients (160 men and 34 women) underwent repair with 87% undergoing endovascular treatment. Ninety-two percent (155) of the patients undergoing endovascular repair in this period were treated with the AneuRx device. These 155 patients were divided into two groups based on gender to compare their early treatment results. The FDA approval of endovascular grafts has profoundly affected the treatment of infrarenal AAAs in the United States. Women continue to account for a small, but complex, proportion of patients treated with available endovascular devices and the results in these patients is worse than their male counterparts. Careful patient selection and meticulous operative techniques are needed to reliably treat women with available endovascular devices. Further developments are necessary to improve the current results and increase the proportion of women being safely and effectively treated with endovascular devices.

Aged↗
PubMed2002

Lower extremity venous thrombolysis with adjunctive mechanical thrombectomy.

PURPOSE: To evaluate the use of adjunctive mechanical thrombectomy (MT) with pharmacologic catheter-directed lower extremity venous thrombolysis. MATERIALS AND METHODS: Catheter-directed thrombolysis with adjunctive MT was used to treat 28 symptomatic limbs in 20 patients (22 procedures) with lower extremity deep vein thrombosis (DVT) between August 1997 and July 2001. Procedural success, major bleeding, thrombolytic infusion time, and total thrombolytic agent dose were recorded. RESULTS: Procedural success was achieved in 23 of 28 limbs (82%). Fifteen patients (18 limbs) received iliac vein stents. Major bleeding was observed after three of 22 procedures (14%) and resulted in transfusion in two patients and endometrial ablation in the third patient. Mean per-limb infusion time was 16.8 hours +/- 12.8. Mean per-limb total doses were lower than those reported in published studies of DVT thrombolysis: 2.67 million U +/- 1.60 urokinase, 18.4 mg +/- 10.7 tissue plasminogen activator, and 13.8 U +/- 6.9 reteplase. Venographic analysis demonstrated minimal thrombus removal (26.0% +/- 24.1) when using MT alone, compared with substantial thrombus removal (62.0% +/- 24.9) when using MT after pharmacologic thrombolytic agents had been administered (P =.006). CONCLUSION: The use of adjunctive MT to augment pharmacologic catheter-directed DVT thrombolysis provides comparable procedural success and may reduce the required thrombolytic dose and infusion duration.

Aged↗
PubMed2002

I. Uterine fibroid embolization: preprocedure assessment.

Increasing clinical experience with uterine fibroid embolization (UFE) has improved the ability of interventionalist radiologists to discern who is and who is not an appropriate candidate for this procedure. Initial evaluation should be directed at obtaining answers to the following key questions: (1) Does the patient have uterine fibroids that account for her symptoms and are they severe enough to require invasive treatment? (2) Does she desire future childbearing? (3) Are there any clinical indications or imaging signs of uterine malignancy? (4) Are there any medical or anatomic features that would favor a particular therapeutic modality? (5) What are her own preferences regarding treatment? Ultrasound and magnetic resonance imaging are vital elements to the assessment and planning of the appropriate course of action. Given the lack of prospective comparative trials between UFE and surgical treatment, recommendations are often highly influenced by patient preference.

Embolization, Therapeutic↗
PubMedDate not supplied

Renal artery stent placement complicated by development of a Type B aortic dissection.

Percutaneous renal artery angioplasty and stent placement have demonstrated safety and effectiveness in the treatment of selected patients with renovascular hypertension and ischemic nephropathy. Major complications have been predominantly confined to the affected renal artery and kidneys, including renal artery dissection and/or thrombosis, distal embolization, and contrast-related nephropathy. We report a case in which treatment of an ostial renal artery lesion with placement of a balloon-expandable stent was complicated by the development of an acute Type B aortic dissection.

Aged↗