Minimally Invasive Percutaneous Treatment of Small Renal Tumors with Irreversible Electroporation: A Single-Center Experience.

PURPOSE: To evaluate whether irreversible electroporation (IRE) can be used as an ablation technique for small renal tumors (T1a cancers or small benign tumors) and to describe features after ablation on computed tomography (CT) or magnetic resonance (MR) imaging. MATERIALS AND METHODS: In this retrospective study, 20 patients (mean age, 65 y ± 12.8 y) underwent CT-guided IRE of T1a renal carcinoma (n = 13) or small benign or indeterminate renal masses < 4 cm in size (n = 7). Mean tumor size was 2.2 cm ± 0.7. The ablation area was verified with contrast-enhanced imaging performed immediately after the procedure to determine technical success. Imaging was performed 6 weeks (20 of 20 patients), 6 months (15 of 20), and 12 months (6 of 20) after ablation. Medical records and CT/MR imaging features of all patients were reviewed for recurrence, symptoms, and complications after treatment. RESULTS: Technical success was achieved in all patients (100%); there were no major procedure-related complications. Minor complications occurred in 7 patients, including self-limiting perinephric hematomas, pain difficult to control, and urinary retention. Mean procedure time was 2.0 hours ± 0.7. At 6 weeks, 2 patients required salvage therapy because of incomplete ablation. At 6 months, all 15 patients with imaging studies available had no evidence of recurrence. At 1 year, 1 patient (1 of 6) was noted to have experienced recurrence. CT/MR imaging after IRE ablation demonstrated an area of nonenhancement in the treatment zone that involuted over ~6 months. CONCLUSIONS: Renal IRE appears to be a safe treatment for small renal tumors. Tumors treated with IRE demonstrated nonenhancement in the treatment zone with involution on follow-up CT/MR imaging.

Bleeding after laparoscopic supracervical hysterectomy managed with cervical artery embolization. A case report.

BACKGROUND: Postoperative bleeding is a known complication after laparoscopic supracervical hysterectomy (LASH), and trachelectomy is the traditional management of significant bleeding. CASE: We present the case of a patient with significant postoperative bleeding 1 month after LASH, resulting in symptomatic anemia requiring blood transfusion. Gelfoam embolization of the bilateral cervical arteries was successful in stopping the bleeding. The patient had no further bleeding and had resolution of anemia at 6 months postprocedure. CONCLUSION: Our case demonstrates a successful multidisciplinary and minimally invasive approach to management of postoperative bleeding with bilateral cervical artery embolization and should be considered as a potential treatment option.

Salvage of angioplasty failures and complications in hemodialysis arteriovenous access using the FLUENCY Plus Stent Graft: technical and 180-day patency results.

PURPOSE: To review technical and 180-day clinical outcomes when stent grafts were used to treat dysfunctional arteriovenous (AV) hemodialysis access circuits. MATERIALS AND METHODS: The FLUENCY Plus Stent Graft (Bard Peripheral Vascular, Tempe, Arizona) was used to salvage percutaneous transluminal angioplasty (PTA) technical failures and complications in AV access circuits over 2 years. There were 106 patients treated with 138 stent grafts. Indications for stent graft use included residual stenosis after PTA (n = 81), extravasation after PTA (n = 22), early recurrent stenosis (n = 14), pseudoaneurysms (n = 4), and "other" (n = 4). Data were retrospectively analyzed for complications and outcomes. RESULTS: Technical success was achieved in all patients, and clinical success was achieved in 104 (98%) of 106 patients. At 180 days, postintervention primary patency (PIPP) was 47%, and postintervention secondary patency (PISP) was 79%. PIPP was 62% for autogenous fistulas (AVFs) and 35% for prosthetic grafts (AVGs) (P = .010). The 180-day PIPP for stent grafts 9-10 mm in diameter was 63% versus 38% for stent grafts 6-8 mm in diameter (P = .012). Implants that did not cross the elbow had a 180-day PIPP of 47% compared with 25% for implants across the elbow (P = .032). Technical complications were periprocedure AVG thromboses (n = 2), intraprocedural stent graft dislodgment (n = 1), venospasm (n = 2), and contrast agent-related hives (n = 1). One patient returned at 2 months with an infected AVG and stent graft in the outflow vein. CONCLUSIONS: The FLUENCY Plus Stent Graft was effective for maintenance of hemodialysis access circuit patency and was comparable or better than historical outcomes for PTA and bare stents. Factors that favored improved patency included larger diameter devices, use in AVFs, and avoiding placement across the elbow joint.

Common and rare collateral pathways in aortoiliac occlusive disease: a pictorial essay.

OBJECTIVE: The development of collateral pathways for arterial blood flow is common in the presence of atherosclerotic occlusive disease of the abdominal aorta and iliac arteries. The collateral pathways are divided into systemic-systemic and systemic-visceral pathways. MDCT is commonly used to evaluate aortic stenosis and the resulting collateral pathways. CONCLUSION: Common and rare arterial collateral pathways are reviewed by 3D volume-rendered CT images. Visceral and lower extremity arterial embryology is reviewed.

ACR-ABS-ACNM-ASTRO-SIR-SNMMI practice parameter for selective internal radiation therapy or radioembolization for treatment of liver malignancies.

PURPOSE: The American College of Radiology (ACR), American Brachytherapy Society (ABS), American College of Nuclear Medicine (ACNM), American Society for Radiation Oncology (ASTRO), Society of Interventional Radiology (SIR), and Society of Nuclear Medicine and Molecular Imaging (SNMMI) have jointly developed a practice parameter on selective internal radiation therapy (SIRT) or radioembolization for treatment of liver malignancies. Radioembolization is the embolization of the hepatic arterial supply of hepatic primary tumors or metastases with a microsphere yttrium-90 brachytherapy device. MATERIALS AND METHODS: The ACR -ABS -ACNM -ASTRO -SIR -SNMMI practice parameter for SIRT or radioembolization for treatment of liver malignancies was revised in accordance with the process described on the ACR website (https://www.acr.org/ClinicalResources/Practice-Parameters-and-Technical-Standards) by the Committee on Practice Parameters-Interventional and Cardiovascular Radiology of the ACR Commission on Interventional and Cardiovascular, Committee on Practice Parameters and Technical Standards-Nuclear Medicine and Molecular Imaging of the ACR Commission on Nuclear Medicine and Molecular Imaging and the Committee on Practice Parameters-Radiation Oncology of the ACR Commission on Radiation Oncology in collaboration with ABS, ACNM, ASTRO, SIR, and SNMMI. RESULTS: This practice parameter is developed to serve as a tool in the appropriate application of radioembolization in the care of patients with conditions where indicated. It addresses clinical implementation of radioembolization including personnel qualifications, quality assurance standards, indications, and suggested documentation. CONCLUSIONS: This practice parameter is a tool to guide clinical use of radioembolization. It focuses on the best practices and principles to consider when using radioemboliozation effectively. The clinical benefit and medical necessity of the treatment should be tailored to each individual patient.

Aortoiliac vascular injuries after misplacement of fixation screws.

PURPOSE: To report our experience with the diagnosis and treatment of aortoiliac vascular injuries caused by misplaced orthopedic fixation screws. MATERIALS: Six patients (age range, 35-60 years; mean, 52 years) were diagnosed with seven arterial injuries related to misplacement of fixation screws. The location of the injuries were thoracic aorta (n = 4) and common iliac arteries (n = 3). There was vessel wall penetration in five injuries resulting in active bleeding in two patients, contained penetrations in two patients, and vessel occlusion in one patient. One patient had associated inferior vena cava injury and pulmonary embolism. Two patients had asymptomatic impingement of the aortic wall by the screws. RESULTS: Vascular injuries resulted in death in one patient and limb amputation in another patient. Three patients were treated with placement of stent grafts and screw removal. Screw replacement was performed in one patient. Conservative observation was done in one patient. CONCLUSIONS: Vascular injuries related to misplacement of fixation screws are relatively infrequent but potential life and limb-threatening complications that require early recognition with prompt repair of vascular lesions and screw reposition.

Rapid cortisol assays improve the success rate of adrenal vein sampling for primary aldosteronism.

OBJECTIVE: We hypothesized that an adrenal vein sampling (AVS) algorithm incorporating rapid cortisol assays, which enables resampling of the adrenal veins, would improve the success rate by a team of radiologists. SUMMARY BACKGROUND DATA: AVS is the most accurate means to localize aldosterone production in primary aldosteronism (PA). However, cannulation of the right adrenal vein (RAV) is difficult, and success is assumed from venography without the support of steroid assays. Furthermore, few institutions can assign all studies to 1 dedicated and experienced AVS interventional radiologist. METHODS: Retrospective chart review of patients with PA at our university hospitals who underwent AVS. We compared results for 30 AVS studies incorporating rapid cortisol assays with 30 conventional AVS studies. RESULTS: The success rate for the control period was 73% (22/30 studies). For the first 30 studies after incorporating rapid cortisol assay, the success rate increased to 97% (29/30 studies). Resampling the RAV was required for 2 studies, and prolonged sheath insertion did not cause any complications. CONCLUSIONS: High AVS success rates may be achieved by a team of interventional radiologists at 1 center using defined AVS protocols. Rapid cortisol assay allows for resampling of the RAV and improves AVS success rates.

Volume associated dynamic geometry and spatial orientation of the inferior vena cava.

BACKGROUND: The geometry and dynamics of the vena cava are poorly understood and current knowledge is largely based on qualitative data. The purpose of this study is to quantitate the dimensional changes that occur in the infrarenal inferior vena cava (IVC), in response to changes in intravascular volume. METHODS: IVC dimensions were measured at 1 cm and 5 cm below the renal veins, on serial contrasted computed tomographic (CT) scans, in 30 severely injured trauma patients during hypovolemic (admission) and fluid resuscitated (follow-up) states. Changes in volume of the infrarenal segment were calculated and correlated with changes in IVC diameter and orientation. The orientation of the infrarenal caval segment was quantified as the angulation of the major axis from the horizontal. A representation of the IVC diameter, as would be seen on standard anterior-posterior venographic imaging, was determined by projecting the CT image of the major axis onto a coronal plane. CT representations of venographic diameters were compared with measurements of the true major axis to assess accuracy of venograms for caval sizing and filter selection. RESULTS: All patients had evidence of a collapsed IVC (<15 mm minor axis dimension) on admission. Mean time between admission and follow-up CT was 49.5 (range: 1-202) days. The volume of the infrarenal segment increased more than twofold with resuscitation, increasing from 6.9 +/- 2.2 (range: 3.1-12.4) mL on admission, to 15.7 +/- 5.0 (range: 9.2-28.5) mL on follow-up (P < .01). At both 1 and 5 cm below the renal veins, the IVC expanded anisotropically such that the minor axis expanded up to five times its initial size accommodating 84% of the increased volume of the segment, while only small diameter changes were observed in the major axis accounting for less than 5% of the volume increase (P < .001). Further, the IVC was left-anterior-oblique in all patients, with the major axis 26 degrees off the horizontal on average. This orientation did not change significantly with volume resuscitation (P > 0.5). The obliquity of the IVC resulted in significant underestimation of caval size of up to 6.8 mm, when using the venographic representation for sizing instead of the true major axis (P < 0.001). CONCLUSIONS: In response to changes in intravascular volume, the IVC undergoes profound anisotropic dimensional changes, with greater displacement seen in the minor axis. In addition, the IVC is oriented left-anterior oblique and caval orientation is not altered by changes in volume status. IVC obliquity may result in underestimation of caval size by anterior-posterior venogram.

MDCT angiography of mesenteric bypass surgery for the treatment of chronic mesenteric ischemia.

OBJECTIVE: Chronic mesenteric ischemia (CMI) is a serious condition that requires surgical or endovascular intervention. Surgical revascularization for the treatment of CMI uses different operative techniques including endarterectomy, vessel reimplantation, and mesenteric bypass. A basic understanding of the operative techniques is essential for the adequate interpretation of imaging studies in patients who have undergone surgery for CMI. In this article, we review the different operative techniques used in the treatment of CMI, discuss the results of surgical intervention for CMI, and illustrate how MDCT angiography (MDCTA) can be used for follow-up and for the detection of early and late complications after surgery. CONCLUSION: MDCTA is a powerful tool for the postoperative evaluation of patients with CMI. Early detection of graft dysfunction is critical to prevent graft occlusion and the development of potentially fatal mesenteric ischemia. MDCTA can detect early and late complications after surgery and guide additional surgical or endovascular interventions.

Neoaortoiliac reconstructions using femoropopliteal veins: MDCT angiography findings.

OBJECTIVE: In this article, we discuss the neoaortoiliac system procedure, a surgical procedure that uses femoropopliteal vein segments for arterial reconstructions in patients with aortofemoral prosthetic graft infections. CONCLUSION: CT angiography (CTA) is a powerful imaging tool that can be used in the follow-up of patients after this complex surgery. CTA accurately detects early and late complications that may develop after the neoaortoiliac system procedure.

Multidetector CT angiography of infrainguinal arterial bypass.

Infrainguinal arterial bypass (IGAB) surgery is commonly performed in patients with claudication, critical limb ischemia, or other arterial problems in the lower extremities. An IGAB is constructed from different materials depending on the anatomy of the lesion and the availability of an autogenous vein. The ideal material for IGAB is the greater saphenous vein, especially for distal below-knee bypass. In patients with no available autogenous vein, IGAB can be performed by using different prosthetic materials or biologic grafts. After the surgery, periodic surveillance is performed with duplex ultrasonography and clinical assessment of peripheral pulses and ankle-brachial indexes. If complications are detected, further work-up is performed with conventional arteriography, multidetector computed tomographic (CT) angiography, or magnetic resonance angiography. CT angiography has become a powerful tool for assessing the potential early and late complications of IGAB and for planning further therapy in a fast, reliable, and noninvasive manner.

Measurement of 18-hydroxycorticosterone during adrenal vein sampling for primary aldosteronism.

CONTEXT: In primary aldosteronism, elevated serum 18-hydroxycorticosterone (18OHB) suggests aldosterone-producing adenoma (APA) rather than bilateral, idiopathic hyperaldosteronism (IHA), but little is known about the relative production of 18OHB and aldosterone (A) in APAs compared with IHA. OBJECTIVES: We measured 18OHB, A, and cortisol (F) in blood from adrenal vein sampling (AVS) studies. We compared the discriminatory power of gradients in 18OHB/A and 18OHB/F ratios with A/F ratio gradients for distinguishing APA from IHA. DESIGN, SETTING, AND SUBJECTS: We measured 18OHB and A in excess serum from 23 AVS studies performed at our university hospitals. MAIN OUTCOME MEASURES: We calculated the ratios 18OHB/A, 18OHB/F, and A/F for all specimens, and determined the adrenal vein gradients for these ratios. RESULTS: The 18OHB/A ratios were much lower in blood draining APAs (2.17 +/- 0.62) than in blood draining the contralateral adrenals (12.96 +/- 12.76; P < 0.001) but similar to blood draining IHA adrenals (4.69 +/- 4.32; P = 0.02). In contrast, the 18OHB/F ratios were elevated in specimens from APAs (26.03 +/- 11.51) compared with IHA adrenals (9.22 +/- 5.18; P < 0.001) or the contralateral adrenals (6.23 +/- 2.97; P < 0.001). Using 18OHB/F gradient greater than two or 18OHB/A gradient less than 0.5 as criteria for lateralization, interpretations agreed with lateralizations based on A/F gradients in 21 of 23 cases. CONCLUSIONS: High serum 18OHB in APA reflects augmented production of both 18OHB and A, not disproportionate 18OHB secretion relative to A. The 18OHB/A and 18OHB/F gradients are useful adjuncts but not as reliable as A/F gradients for A lateralization during AVS.

Durable oncologic outcomes after radiofrequency ablation: experience from treating 243 small renal masses over 7.5 years.

BACKGROUND: Long-term oncologic outcomes for renal thermal ablation are limited. The authors of this report present their experience with radiofrequency ablation (RFA) therapy for 243 small renal masses (SRMs) over the past 7.5 years. METHODS: The authors' institutional, prospectively maintained RFA database was reviewed to determine intermediate and long-term oncologic outcomes for patients with SRMs (generally < 4 cm) who underwent RFA. Particular attention was placed on patients who had a minimum 3 years of follow-up. Patients were excluded from the analysis if they had received previous treatment for renal cell carcinoma (RCC) on the ipsilateral kidney or if they did not have at least 1 imaging study available for follow-up. RESULTS: Two hundred eight patients (with 243 SRMs) who had no evidence of previous ipsilateral renal cancer treatment underwent RFA and had follow-up imaging studies available for review. Overall, tumor size averaged 2.4 cm, and follow-up ranged from 1.5 months to 90 months (mean, 27 months). Of the 227 tumors (93%) that underwent preablation biopsy, RCC was confirmed in 79%. The initial treatment success rate was 97%, and the overall 5-year recurrence-free survival rate was 93% (90% for 160 patients who had biopsy-proven RCC). During follow-up, 3 patients developed metastatic disease, and 1 patient died of RCC, yielding 5-year actuarial metastasis-free and cancer-specific survival rates of 95% and 99%, respectively. CONCLUSIONS: RFA provided successful treatment of SRMs and produced a low rate of recurrence as well as prolonged metastasis-free and cancer-specific survival rates at 5 years after treatment. Although longer term follow-up of RFA will be required to determine late recurrence rates, the current results indicated a minimal risk of disease recurrence in patients who are >3 years removed from RFA.