Intravascular US: Applications in Interventional Radiology.

Interventional radiology applications of intravascular US (IVUS) continue to expand, complementing intraprocedural angiography and providing a unique vantage from which to guide endovascular interventions. Vascular pathologic conditions become sonographically visualized rather than inferred from the planar appearance of the opacified vascular lumen. Perivascular targets become sonographically visualized rather than approximated on the basis of fluoroscopic landmarks. The authors introduce broad categories of IVUS catheters, namely radial and side-firing varieties, as well as prevailing options for each and their technical specifications. Common applications within interventional radiology are covered in a systems approach, including deep venous thrombosis, May-Thurner syndrome, nutcracker syndrome, transjugular intrahepatic portosystemic shunts, aortic interventions, peripheral arterial disease, and endovascular or perivascular biopsy. Discussions are accompanied by technical pearls from the authors, and summarized evidence where IVUS has been shown to reduce procedural time, intravascular contrast agent dose, radiation exposure, and morbidity in each space is presented. Finally, emerging applications and future directions are discussed. ©RSNA, 2022.

A 16-F Sheath with Endobronchial Forceps Improves Reported Retrieval Success of Long-Dwelling "Closed Cell" Inferior Vena Cava Filter Designs.

PURPOSE: To report results of a 16-F sheath/endobronchial forceps combination in retrieval of "closed cell" inferior vena cava (IVC) filter designs with prolonged dwell times of ≥ 60 days. MATERIALS AND METHODS: Forceps retrieval of selected IVC filters using a 16-F 45-cm sheath was performed in 35 patients (25 women and 10 men). Patients presented with filters that were no longer needed without (n = 10) or with (n = 21) prior failed retrieval, caval thrombosis before lysis (n = 3), and back pain (n = 1). Filter designs included 19 Günther Tulip (54%), 10 Option (29%), and six OptEase (17%). Mean dwell time was 977 days. Imaging characteristics, technical success, fluoroscopy time, and complications were recorded. RESULTS: Filters included 20 tip-embedded, 6 tip-adherent, 4 fractured, and 6 containing thrombus. All were strut and wall-embedded. Initial snare failures occurred in 8 filters because of hook straightening (n = 4), adherent material (n = 2), snare breakage (n = 1), and filter tilt (n = 1). The 16-F sheath/forceps combination was 100% successful in removing filters. In 1 patient, 2 extravascular fragments could not be retrieved. Median fluoroscopy time, excluding 3 extended lysis procedures, was 8 minutes. Minor caval abnormalities, including caval spasm and caval defects, were noted in 17 patients, and filter fracture occurred in 2 patients. No major complications occurred. CONCLUSIONS: A high rate of retrieval for closed cell long-dwelling strut and wall-embedded filters may be achieved using a 16-F sheath/endobronchial forceps combination.

Percutaneous Endovascular Aneurysm Repair: Current Status and Future Trends.

Endovascular aneurysm repair (EVAR) is a common, safe, and effective method of treating abdominal aortic aneurysms. Traditionally treated via surgical cutdown over the common femoral arteries, many recent studies demonstrate percutaneous access techniques to avoid the surgical cutdown. Developing familiarity with these percutaneous techniques, including risks, complications, adjuncts, and alternative accesses, can help improve the outcomes and availability of EVAR. As these techniques become increasingly common, it is not unlikely that they can be practiced safely in select patients in an outpatient setting.

Pharmacology of Peripheral Arterial Disease in the Angio Suite: What Every Interventionalist Should Know.

Safe and effective treatment of peripheral arterial disease (PAD) and critical limb ischemia can be routinely performed in the angiography suite. A systematic understanding of the medications commonly used during these procedures is essential. This review discusses the traditional roles of the medications used in PAD procedures, the existing evidence basis for those roles, potential alternatives, and evolving techniques. Developing a familiarity with these medications can help improve outcomes and safety for the patients being treated.

The Current Status of the Interventional Radiology Fellowship Match: Results of a Resident Survey.

PURPOSE: To survey residents who participated in the 2015 interventional radiology fellowship match regarding the overall process, including the number of interviews received, programs ranked, money spent, and perceived effect on board preparation. METHODS: An IRB-approved, anonymous web-based survey was distributed via email link to 151 individuals in 41 states who had interview at 1 of 2 IR fellowship programs in the United States. Most of the survey's 12 questions were based on a five-point Likert scale, while others were free-text response. RESULTS: Seventy-five out of 151 residents completed the survey (response rate 49.7%). When asked if the current timing of the core board examination worked well with the IR interview schedule, 62 (96.6%) either strong disagreed or disagreed. Sixty respondents (87%) reported that preparing for and traveling to IR interviews had a very negative or somewhat negative effect on boards preparation. When asked what change they would make to the timing of IR interviews or the core examination, 55 (79.7%) thought that IR fellowship interviews should occur earlier in the year. The median number of IR programs applied to, interviews offered, interviews completed, and programs ranked were 28, 13, 10, and 10, respectively. When asked how much money was spent on the application and interview process, 39% spent between $5000 and $9999, and 17% spent more than $10000. CONCLUSIONS: A substantial percentage of radiology residents who participated in the 2015 IR fellowship match have concerns about the proximity of board preparation to the match process. Consideration for restructuring the timing of this process is recommended.

Percutaneous Femoropopliteal Recanalization Using a Completely Transpedal/Transtibial Approach.

PURPOSE: To report preliminary experience with femoropopliteal revascularization using a completely transpedal/transtibial approach. MATERIALS AND METHODS: Three patients with Rutherford 3-4 disease underwent revascularization of TASC C/D lesions using a pedal/tibial artery as the only site of arterial access. RESULTS: One patient with a chronic superficial femoral artery occlusion had continuity achieved to the common femoral artery using a dedicated reentry device and stenting; in a second patient, an occluded popliteal artery stent was successfully revised with an endograft; and in a third patient with morbid obesity, a chronic SFA occlusion was successfully stented. All patients experienced complete resolution of presenting symptoms; no puncture site complications were seen. CONCLUSIONS: Use of a pedal/tibial approach as the sole site of arterial access may become an important access technique for femoropopliteal revascularization when patients have limited femoral access options.

Correlation of Peripheral Vein Tumour Marker Levels, Internal Iliac Vein Tumour Marker Levels and Radical Prostatectomy Specimens in Patients with Prostate Cancer and Borderline High Prostate-Specific Antigen: A Pilot Study.

PURPOSE: To correlate prostate-specific antigen (PSA), free to total PSA percentage (fPSA%) and prostatic acid phosphatase (PAP) levels from peripheral and pelvic venous samples with prostatectomy specimens in patients with prostate adenocarcinoma and borderline elevation of PSA. MATERIALS AND METHODS: In this prospective institutional review board approved study, 7 patients with biopsy proven prostate cancer had a venous sampling procedure prior to prostatectomy (mean 3.2 days, range 1-7). Venous samples were taken from a peripheral vein (PVS), the right internal iliac vein, a deep right internal iliac vein branch, left internal iliac vein and a deep left internal iliac vein branch. Venous sampling results were compared to tumour volume, laterality, stage and grade in prostatectomy surgical specimens. RESULTS: Mean PVS PSA was 4.29, range 2.3-6 ng/ml. PSA and PAP values in PVS did not differ significantly from internal iliac or deep internal iliac vein samples (p > 0.05). fPSA% was significantly higher in internal iliac (p = 0.004) and deep internal iliac (p = 0.003) vein samples compared to PVS. One of 7 patients had unilateral tumour only. This patient, with left-sided tumour, had a fPSA% of 6, 6, 6, 14 and 12 in his peripheral, right internal iliac, deep right internal iliac branch, left internal iliac and deep left internal iliac branch samples respectively. There were no adverse events. CONCLUSION: fPSA%, unlike total PSA or PAP, is significantly higher in pelvic vein compared to peripheral vein samples when prostate cancer is present. Larger studies including patients with higher PSA values are warranted to further investigate this counterintuitive finding.

Iatrogenic percutaneous vascular injuries: clinical presentation, imaging, and management.

Vascular interventional radiology procedures are relatively safe compared with analogous surgical procedures, with overall major complication rates of less than 1%. However, major vascular injuries resulting from these procedures may lead to significant morbidity and mortality. This review will discuss the etiology, clinical presentation, diagnosis, and management of vascular complications related to percutaneous vascular interventions. Early recognition of these complications and familiarity with treatment options are essential skills for the interventional radiologist.

Synthesis of C-linked glycopyranosyl serines via a chiral glycine enolate equivalent.

[formula: see text] The stereoselective preparation of C-linked D-gluco- and D-galactopyranosyl L-serines in their alpha and beta forms is herein reported. The syntheses require the conversion of the allyl C-glycopyranosides into their iodoethyl derivatives, which then undergo substitution with the Williams' chiral glycine enolate equivalent. Deprotection and acetylation affords Boc-protected amino acids for peptide synthesis.