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Biomedical subjects

David J Spinosa

Publications and source records attributed to David J Spinosa.

At least 19 recordsLinked to original sources
PubMed2005

Magnetic resonance urography for the assessment of potential renal donors: comparison of the RARE technique with a low-dose gadolinium-enhanced magnetic resonance urography technique in the absence of pharmacological and mechanical intervention.

The aim of this study was to determine whether magnetic resonance urography without pharmacological (diuretic) stimulation and mechanical compression allows conclusive evaluation of the urinary system in potential renal donors. In 28 consecutive patients magnetic resonance urography (MRU) was performed on a 1.5-T system. Two techniques, rapid acquisition with relaxation enhancement (RARE) and a gadolinium (Gd)-enhanced 3D fast low angle shot (FLASH) sequence were compared in the absence of adjunctive measures. Two reviewers assessed image quality, presence of artifacts and completeness of visualization of the collecting systems and ureters. Among the 53 MR urograms, there was no difference in image quality and presence of artifacts between RARE and Gd-MRU. Despite high image quality, visualization of the urinary collecting system was insufficient. Continuous visualization from the collecting system to the distal ureter was demonstrated bilaterally in only 14% of the RARE and 26% of Gd-enhanced MR urograms, respectively. Overall, Gd-enhanced MRU was superior to the RARE technique in displaying the segments of the urinary collecting system, but this difference was not found to be statistically significant. Neither the RARE technique nor the gadolinium-enhanced MRU technique is accurate enough to allow the evaluation of the collecting system and ureters in potential renal donors in the absence of pharmacological intervention and compression.

Adult↗
PubMed2005

Evaluation of an absorbable cyanoacrylate adhesive as a suture line sealant.

BACKGROUND: Previous formulations of cyanoacrylate, though very effective, proved to have too high a tissue reactivity to be used internally. A novel cyanoacrylate compound with less tissue reactivity was recently developed. The objective of this study was to assess this novel cyanoacrylate compound for the use as vascular suture line sealant. MATERIALS AND METHODS: Twelve adult female sheep received a 6 mm PTFE interposition graft in each iliac artery, for a total of 24 grafts. Using oxidized cellulose (Surgicel) as a control, two formulations of a new cyanoacrylate compound (named "compound A" and "compound B") were assessed during this trial. Hemostatic efficiency was measured at the time of operation by the assessment of bleeding time and amount of blood loss. Long-term graft patency was assessed angiographically at 4, 6, and 18 months. Tissue reaction at 2 weeks, 1, 6, and 18 months was assessed grossly by vascular surgeons and microscopically by a blinded pathologist. RESULTS: Average time to hemostasis was 37.6, 50.6, and 219 s in group A, group B, and oxidized cellulose control groups, respectively (P<or=0.001 for both compounds versus control). There were no significant differences between groups with regards to graft patency. Histopathology analysis demonstrated mild to moderate tissue reaction at 2 weeks and 1 month in the cyanoacrylate groups compared with controls at 1 month (ANOVA P=0.004). Mild tissue reaction was seen at 6 months and 18 months, with no significant differences between groups (ANOVA P=0.08, 0.62, respectively). CONCLUSIONS: The novel cyanoacrylate compound examined in this study is a highly effective suture line sealant with only mild tissue reactivity and no significant effects on graft patency when studied over an 18 month period.

Anastomosis, Surgical↗
PubMed2005

Subintimal arterial flossing with antegrade-retrograde intervention (SAFARI) for subintimal recanalization to treat chronic critical limb ischemia.

PURPOSE: To describe the technique of subintimal arterial flossing with antegrade-retrograde intervention (SAFARI) to improve technical success for the performance of subintimal recanalization when there is failure to reenter the distal true lumen or when there is a limited segment of patent distal target artery available for reentry. MATERIALS AND METHODS: Subintimal recanalization was attempted in an antegrade direction in all patients. If reentry into the distal true lumen was unsuccessful or a short segment of target artery was present, retrograde access was obtained in the distal target artery (popliteal, anterior tibial/dorsalis pedis, or posterior tibial) and a retrograde subintimal channel was created. A guide wire was used to connect the retrograde and antegrade subintimal channels simultaneously to create a "flossing" guide wire. The subintimal tract was dilated with balloon angioplasty with or without stent implantation. Limb salvage, amputation-free survival, and survival rates over time were determined. RESULTS: The SAFARI technique resulted in successful subintimal recanalization creating straight-line flow to the foot in all 21 limbs in 20 patients in which the technique was attempted. Antegrade-retrograde access was performed with the femoral artery and the following vessels: popliteal, n = 11; anterior tibial/dorsalis pedis, n = 10; and posterior tibial, n = 2 (two limbs involved multiple accesses). All procedures were successful. The limb salvage rate with SAFARI was 90% (95% CI, 74%-100%) at 6 months. CONCLUSIONS: The SAFARI technique can be useful for completing subintimal recanalization when there is failure to reenter the distal true lumen from an antegrade approach or when there is limited distal target artery available for reentry. The SAFARI technique improves technical success in the performance of subintimal recanalization. Limb salvage rates are comparable to those with antegrade subintimal recanalization.

Aged↗
PubMed2005

Contrast-enhanced MR angiography at 1.5 T after implantation of platinum stents: in vitro and in vivo comparison with conventional stent designs.

OBJECTIVE: The objective of our study was to evaluate the in vitro and in vivo 3D contrast-enhanced MR angiography characteristics of a new platinum-based balloon-expandable stent system and compare this system with a variety of competing metallic stents. MATERIALS AND METHODS: All experiments were performed on 1.5-T scanners. In vitro experiments were performed using 10 stents implanted into a custom-built phantom. Different orientations of the stents along the magnetic field and multiple flip angles were examined. In addition, 19 patients underwent contrast-enhanced MR angiography after the implantation of 36 stents, including four patients with six platinum stents. Angiographic correlation was available for all 19 patients, and luminal patency and stent-induced artifacts were assessed quantitatively. RESULTS: Of the tested balloon-expandable stents, only the platinum-based stents created artifact causing luminal narrowing of 30% or less. All other balloon-expandable stents induced larger artifacts that resulted in higher degrees of narrowing. Thus, if patent, the platinum-based stents allow significant in-stent stenosis to be ruled out reliably. Selected nitinol- or tantalum-based self-expandable stents also are suitable in this regard. CONCLUSION: Of the tested devices, platinum-based stents are the only type of currently available balloon-expandable stent that creates 30% or less artifact-induced apparent stenosis and thus are suitable for MR angiography.

Aged↗
PubMed2004

Pancreatic pseudoaneurysm in a child with hereditary pancreatitis: diagnosis with multidetector CT angiography.

Pseudoaneurysm formation is a serious vascular complication of pancreatitis. It most commonly affects splenic and gastroduodenal arteries. We report a rare case of superior mesenteric artery pseudoaneurysm in a child with hereditary pancreatitis. Multidetector CT angiography allowed the comprehensive assessment of the aneurysm and allowed accurate surgical planning obviating the need for catheter angiography.

Aneurysm, False↗
PubMed2004

Percutaneous intentional extraluminal recanalization in patients with chronic critical limb ischemia.

PURPOSE: To review percutaneous intentional extraluminal recanalization (PIER) for treatment of patients who are poor candidates for infrainguinal arterial bypass surgery (IABS) and have arterial occlusions and chronic critical limb ischemia (CCLI). MATERIALS AND METHODS: Patients with CCLI who were poor candidates for IABS were candidates for PIER. PIER was performed to create continuous arterial flow to the foot for limb salvage. PIER was attempted in 40 patients (22 men, 18 women; median age, 69 years; age range, 44-87 years). Of these patients, 24 (60%) had diabetes, 17 (42%) had renal disease, and 26 (66%) had coronary artery disease. Wound healing was evaluated at follow-up. Kaplan-Meier curves were constructed to evaluate limb salvage, survival, and amputation-free survival. RESULTS: Fifty procedures were attempted in 44 limbs. Tissue loss was present in 40 (91%) limbs, and rest pain was present in four (9%); technical success occurred in 38 (86%). Thirty-seven (84%) of 44 limbs treated with PIER involved tibial vessels (tibial vessels only, n = 15; tibial and superior femoral artery [SFA] and/or popliteal vessels, n = 22). Sixty-six infrainguinal arterial vessel segments (SFA, n = 29; tibial, n = 37) in 38 limbs (1.7 segments per limb) were successfully treated with PIER. Thirty-five (95%) of 37 tibial occlusions and 24 (83%) of 29 SFA and/or popliteal occlusions were longer than 10 cm. Median run-off scores were 5.3 (range, 3-8) and 6.6 (range, 3-9) for patients with tibial occlusions and SFA and/or popliteal occlusions, respectively, as scored with modified Rutherford weighting of run-off arteries. Median follow-up was 7.8 months (range, 1-24 months). Twelve months after PIER, Kaplan-Meier analysis showed limb salvage rate was 66%, survival rate was 71%, and amputation-free survival rate was 48% in these patients. The 30-day mortality rate was 2.5%. Major complications occurred in four (10%) patients, and minor complications occurred in an additional four (10%). CONCLUSION: PIER is a useful percutaneous technique for limb salvage in patients with CCLI.

Adult↗
PubMed2004

Subintimal recanalization is safe and effective in treating chronic critical limb ischemia in selected patients.

Subintimal recanalization is a percutaneous technique that allows revascularization in patients with limb-threatening ischemia. It was first described by Bolia (Cardiovasc Intervent Radiol 13;357-63:1990) but has not gained widespread use in the United States. Twenty-five patients with 32 threatened limbs were referred from a single surgeon's practice over a 23-month period. All patients were either high-risk surgical patients, due to severe medical comorbidities, or not surgical candidates due to poor target vessels, lack of appropriate conduit, or failed previous surgical revascularizations. The average age of patients was 69. There were 15 men and 10 women treated. Subintimal recanalization was immediately successful in 30 limbs. One peri-procedural death occurred, although this patient underwent a surgical bypass graft procedure in the same hospitalization. Three significant complications occurred (myocardial infarction, ventricular arrhythmia, and gastrointestinal hemorrhage). Primary patency is 83 per cent. Secondary patency is 90 per cent. Limb salvage rate is 88 per cent. Mean follow-up period is 10 months. Eight patients died in the follow-up period due to unrelated causes.

Aged↗
PubMed2003

Selection of stents for treating iliac arterial occlusive disease.

Intravascular stents play an increasingly important role in the treatment of iliac artery occlusive disease and their use has expanded the indications for percutaneous endoluminal therapies. The past several years have seen a sharp increase in the number of commercially available covered and uncovered stents. Knowledge of their design and mechanical properties is crucial for selecting the appropriate stent for a particular type of lesion. In this article, the indications for and results of iliac artery stent placement are reviewed and the various characteristics of the currently available stents that may influence operator choice for use in specific lesions are discussed.

Angiography, Digital Subtraction↗
PubMed2003

Simultaneous antegrade and retrograde access for subintimal recanalization of peripheral arterial occlusion.

Subintimal recanalization can be a useful procedure in selected patients with severe peripheral vascular disease with tissue loss or rest pain and limited surgical bypass options. Technical failure occurs in approximately 20% of patient who undergo percutaneous intentional extraluminal recanalization due to inability to reenter the distal true lumen. A technique to improve technical success when performing subintimal recanalization when there is failure to reenter the distal true lumen or possibly when there is a limited segment of patent distal target vessel for reentry is proposed. Further evaluation of this technique is necessary to confirm its safety and determine its technical and clinical success.

Aged↗
PubMed2002

Utility of percutaneous intervention in the management of tunneled hemodialysis catheters.

A variety of interventional techniques have been developed to restore function to dysfunctional tunneled hemodialysis catheters (THC). The relative efficacies of these techniques were evaluated retrospectively to determine which therapy might be most beneficial. The records of malfunctioning THCs referred to interventional radiology between November 1995 and December 1999 were retrospectively reviewed. Dysfunctional THCs were studied using DSA images obtained while injecting contrast through the lumens of the THCs. The interventions performed were categorized into 1 of 5 groups: no treatment or conservative measures such as vigorous flushing; advancing a guidewire through the THC to reposition the catheter tip or to dislodge a small thrombus; catheter exchange over a guidewire; fibrin stripping of the THC using a loop snare; or prolonged (4 or more hr) direct thrombolytic infusion. A Cox Proportional Hazards model was developed to compare the rate of failure among the procedures. There were 340 THC studies. The catheters were managed as follows: 93 patients received conservative management only, 15 had a guidewire advanced through the catheter, 147 underwent catheter exchange, 62 were treated with a fibrin stripping procedure, and 23 received a thrombolytic infusion. Estimated 30-day patency rates for THCs were 38.2% for conservative management, 30.9% for guidewire manipulation of catheter tip, 53.6% for catheter exchange, 76.1% for fibrin stripping, and 69.8% for thrombolytic infusion. Differences among the treatments were observed (p < 0.01) and pairwise comparisons were made among the treatment groups. Failure rates were significantly higher in the catheter exchange (p <0.01) and guidewire manipulation at catheter tip (p <0.01) groups when compared with the fibrin stripping group. The catheter exchange and guidewire manipulation groups also experienced higher rates of failure when compared with the thrombolytic infusion group, although the differences were not statistically significant (p = 0.08, p = 0.17, respectively). Four procedure-related complications requiring hospitalization or other intervention occurred. Three of these were in the catheter exchange group with one incidence of sepsis, one drug reaction, and one hematoma. Fibrin stripping and thrombolytic infusion provided the greatest efficacy in the treatment of poorly functioning THCs, but all therapies demonstrated wide-ranging results. Central line exchanges did not provide a superior secondary patency and experienced more complications.

Adolescent↗
PubMed2002

Gadolinium-based contrast agents in angiography and interventional radiology.

Gadolinium is useful as an alternative contrast agent for diagnostic angiographic and interventional procedures in patients with renal insufficiency or a history of a severe reaction to iodinated contrast material. Gadolinium usually is used as a "problem solver" to answer specific diagnostic questions or guide interventional procedures that cannot adequately be defined with CO2 angiography. Because of dose limitations with Gd, careful planning is required prior to its use with angiography or interventional procedures.

Angiography↗
PubMed2002

MR angiography of the renal arteries.

During, the past decade. MRA has evolved from an cxperimental technique into the modality of choice for the noninvasive evaluation of renovascular disease. The recent widespread application of MRA for these indications has been driven primarily by the advent of 3D contrast-enhanced MRA. which provides a fast, reliable technique for imaging large vascular territories and generates images, after postprocessing, similar in appearance to digital subtraction angiography. The cross-sectional volumetric nature of contrast-enhanced MRA affords some advantages over conventional catheter angiography. Although 3D contrast-enhanced MRA forms the backbone of vascular MR studies, several adjunctive sequences are employed to maximize the diagnostic yield of the examination. For example. flow-dependant imaging is used to complement the morphologic images of contrast-enhanced MRA by providing hemodynamic information. As such, MRA is unique among noninvasive imaging modalities in that it offers a comprehensive evaluation of anatomy and function. The availability and reliability of MRA extend renal artery screening to a wider spectrum of patients. Current applications of renal MRA range from detection of renal artery stenosis to evaluation for renal transplant donors.

Humans↗
PubMed2002

MR angiography of the mesenteric vasculature.

MRA has evolved from a research tool to a robust clinical diagnostic modality. In many centers worldwide, it is the technique of choice for evaluating patients with suspected CMI, assessing operability of patients with pancreatic cancer, and investigating the portal system. Evolving indications include the assessment of liver transplant patients before and after transplant and of living related liver transplant donors. The search for the bleeding source in patients with gastrointestinal hemorrhage may be an indication in the future, once intravascular contrast agents become available.

Contrast Media↗
PubMed2002

Body MR venography.

MRV offers unique diagnostic possibilities for detection and characterization of venous disease. It allows evaluation of perivascular and vascular anatomy, evolution of thromboembolic events, and assessment of vascular flow. MRI is a diagnostic tool that can be tailored for a variety of clinical dilemmas, not only DVTs. Continued improvements in hardware and software will expand the role of MRV.

Humans↗