Venous Anatomy and Collateral Pathways of the Pelvis: An Angiographic Review.

The pelvic venous system is complex, with the potential for numerous pathways of collateralization. Owing to stenosis or occlusion, both thrombotic and nonthrombotic entities in the pelvis may necessitate alternate routes of venous return. Although the pelvic venous anatomy and collateral pathways may demonstrate structural variability, a number of predictable paths often can be demonstrated on the basis of the given disease and the level of obstruction. Several general categories of collateral pathways have been described. These pathway categories include the deep pathway, which is composed of the lumbar and sacral veins and vertebral venous plexuses; the superficial pathway, which is composed of the circumflex and epigastric vessels; various iliofemoral collateral pathways; the intermediate pathway, which is composed of the gonadal veins and the ovarian and uterine plexuses; and portosystemic pathways. The pelvic venous anatomy has been described in detail in cadaveric and anatomic studies, with the aforementioned collateral pathways depicted on CT and MR images in several imaging studies. A comprehensive review of the native pelvic venous anatomy and collateralized pelvic venous anatomy based on angiographic features has yet to be provided. Knowledge of the diseases involving a number of specific pelvic veins is of clinical importance to interventional and diagnostic radiologists and surgeons. The ability to accurately identify common collateral patterns by using multiple imaging modalities, with accurate anatomic descriptions, may assist in delineating underlying obstructive hemodynamics and diagnosing specific occlusive disease entities. ©RSNA, 2022.

Interventional Management of Acquired Lymphatic Disorders.

The lymphatic system is a complex network of tissues, vessels, and channels found throughout the body that assists in fluid balance and immunologic function. When the lymphatic system is disrupted related to idiopathic, iatrogenic, or traumatic disorders, lymphatic leaks can result in substantial morbidity and/or mortality. The diagnosis and management of these leaks is challenging. Modern advances in lymphatic imaging and interventional techniques have made radiology critical in the multidisciplinary management of these disorders. The authors provide a review of conventional and clinically relevant variant lymphatic anatomy and recent advances in diagnostic techniques such as MR lymphangiography. A detailed summary of technical factors related to percutaneous lymphangiography and lymphatic intervention is presented, including transpedal and transnodal lymphangiography. Traditional transabdominal access and retrograde access to the central lymph nodes and thoracic duct embolization techniques are outlined. Newer techniques including transhepatic lymphangiography and thoracic duct stent placement are also detailed. For both diagnostic and interventional radiologists, an understanding of lymphatic anatomy and modern diagnostic and interventional techniques is vital to the appropriate treatment of patients with acquired lymphatic disorders. ©RSNA, 2022.

Transsplenic Portal System Catheterization: Review of Current Indications and Techniques.

Multiple diseases of the portal system require effective portal vein access for endovascular management. While percutaneous transhepatic and transjugular approaches remain the standard methods of portal vein access, transsplenic access (TSA) has gained recognition as an effective and safe technique to access the portal system in patients with contraindications to traditional approaches. Recently, the utility of percutaneous TSA has grown, with described treatments including recanalization of chronic portal vein occlusion, placement of stents for portal vein stenosis, portal vein embolization of the liver, embolization of gastric varices, placement of complicated transjugular intrahepatic portosystemic shunts, and interventions after liver transplant. The authors provide a review of percutaneous TSA, including indications, a summary of related portal vein diseases, and the different techniques used for access and closure. In addition, an imaging-based review of technical considerations of TSA interventions is presented, with a review of potential procedural complications. With technical success rates that mirror or rival the standard methods and reported low rates of major complications, TSA can be a safe and effective option in clinical scenarios where traditional approaches are not feasible. ©RSNA, 2022.

Interventional Radiology Management of Adult Liver Transplant Complications.

Liver transplant remains the definitive therapy for patients with end-stage liver disease. Outcomes have continued to improve, in part owing to interventions used to treat posttransplant complications involving the hepatic arteries, portal vein, hepatic veins or inferior vena cava (IVC), and biliary system. Significant hepatic artery stenosis can be treated with angioplasty or stent placement to prevent thrombosis and biliary ischemic complications. Hepatic arterioportal fistula and hepatic artery pseudoaneurysm are rare complications that can often be treated with endovascular means. Treatment of hepatic artery thrombosis can have mixed results. Portal vein stenosis can be treated with venoplasty or more commonly stent placement. The rarer portal vein thrombosis can also be treated with endovascular techniques. Hepatic venous outflow stenosis of the hepatic veins or IVC is amenable to venoplasty or stent placement. Complications of the bile ducts are the most encountered complication after liver transplant. When not amenable to endoscopic intervention, biliary stricture, bile leak, and ischemic cholangiopathy can be treated with percutaneous transhepatic cholangiography with biliary drainage and other interventions. New techniques have further improved care for these patients. Transsplenic portal vein recanalization has improved transplant candidacy for patients with chronic portal vein thrombosis. Spontaneous splenorenal shunt and splenic artery steal syndrome (nonocclusive hepatic artery hypoperfusion syndrome) remain complicated topics, and the role of endovascular embolization is developing. When patients have recurrence of cirrhosis after transplant, most commonly due to viral hepatitis, transjugular intrahepatic portosystemic shunt (TIPS) may be required to treat symptoms of portal hypertension. Online supplemental material is available for this article. ©RSNA, 2022.

Ergonomics in IR.

Ergonomic research in the field of interventional radiology remains limited. Existing literature suggests that operators are at increased risk for work-related musculoskeletal disorders related to the use of lead garments and incomplete knowledge of ergonomic principles. Data from existing surgical literature suggest that musculoskeletal disorders may contribute to physician burnout and female operators are at a higher risk of developing musculoskeletal disorders. This review article aims to summarize the existing ergonomic challenges faced by interventional radiologists, reiterate existing solutions to these challenges, and highlight the need for further ergonomic research in multiple areas, including burnout and gender.

Dose reduction using digital fluoroscopy versus digital subtraction angiography in endovascular aneurysm repair: A prospective randomized trial.

OBJECTIVE: Endovascular aneurysm repair (EVAR) can result in high radiation dose to patients and operators. This prospective randomized study aimed to assess whether patient radiation dose sustained during EVAR could be decreased by predominantly using digital fluoroscopy (DF) vs the standard technique using digital subtraction angiography (DSA). METHODS: Between February 2011 and June 2017, patients with EVAR of infrarenal abdominal aortic aneurysms were prospectively enrolled and randomly assigned to a standard treatment DSA cohort or a DF cohort in which two or fewer DSA acquisitions were allowed for confirmatory imaging. Primary end points included dose-area product (DAP) and cumulative air kerma. Secondary end points included technical success and conversion to DSA standard treatment (if DF was inadequate for visualization). RESULTS: For all 43 patients enrolled (26 in the DF cohort, 17 in the DSA cohort), technical success was 100%. Of the 26 DF patients, 5 (19%) required conversion to the DSA cohort. In an intention-to-treat analysis, mean DAP was significantly lower in the DF cohort than in the DSA cohort (132 vs 174 Gy·cm2; P = .04). When patients were separated by number of DSA acquisitions (two or fewer vs three or more), mean DAP decreased 41% (109 vs 185 Gy·cm2; P = .005) and cumulative air kerma decreased 40% (578 vs 964 mGy; P = .004). CONCLUSIONS: In most patients (81%), DF or limited DSA was adequate for visualization during EVAR. In both intention-to-treat DF and limited-DSA cohorts, mean DAP was significantly decreased. If image quality allows, a DF-only or limited-DSA approach to EVAR decreases radiation dose.

Sample content of kinesthetic educational training: Reducing scattered X-ray exposures to interventional physician operators of fluoroscopy.

Content used by Medical Physicists for fluoroscopy safety training to staff is deliverable via several formats, that is, online content or a live audience slide presentations. Here, we share one example of a kinesthetic (live, hands-on simulation) educational program in use at our facility for some time (~10 years). In this example, the format and content specifically target methods of reducing physician operator exposures from scattered x rays. A kinesthetic format identifies and promotes the adoption of exposure-reducing behaviors. Key kinesthetic elements of this type of training include: physician hands-on measurements of radiation levels at locations specific to their standing positions (e.g., primary arterial access points) in the room using handheld exposure rate meters, measurement of exposure rate reduction to physicians provided by using personal protective equipment, that is, wearable aprons, hanging lead drapes, and pull-down shields. Physician choice of procedure-specific tableside selectable controls affecting exposure rate from optional fluoroscopy, Cine or digital subtraction angiography (DSA), along with comparative measured contribution to physician exposure is demonstrated. The inverse square exposure rate reduction to physicians when stepping back from the table during DSA is a key observation. Kinesthetic simulations in the rooms used by physicians have been found to provide the highest level of understanding giving rise to adoption of practices that are impactful for physicians. Specific training scripts are in place for physician sub-specialization in interventional radiology, cardiology, neurosurgery, vascular surgery, and gastroenterology. This training is used for new physician staff while classroom presentations (whose content mimics in room training) are used with staff who have had previously had in room training.

Natural history and management outcomes of segmental arterial mediolysis.

BACKGROUND: Segmental arterial mediolysis (SAM) is a poorly understood, nonatherosclerotic, noninflammatory disease resulting from arterial medial degeneration. Patients may present with aneurysm, dissection, stenosis, or bleeding from visceral or renal arteries. Treatment algorithms are poorly characterized. METHODS: A retrospective review of all patients diagnosed with SAM was performed at our institution. Patients were identified by established criteria that include clinical presentation in combination with radiographic and serologic findings. Demographics, presenting symptoms, diagnostic evaluation, management, and outcomes were reviewed. RESULTS: There were 117 patients diagnosed with SAM between 2000 and 2016; 67.5% (n = 79) were male. Mean age was 52.7 years (range, 23.4-90 years); 69.2% (n = 81) presented with acute abdominal pain, 22.2% (n = 26) with flank pain, and 19.7% (n = 23) with back pain; 15.4% (n = 18) had abdominal pain longer than 30 days; 13.7% (n = 16) had acute hypertension, and 5.1% (n = 6) were hypotensive; 10.3% (n = 12) were asymptomatic. There were 93 (79.5%) dissections and 61 (52.1%) aneurysms. Hemorrhage was seen in 10 (8.5%). The celiac axis was affected in 54.7% (n = 64), renal arteries in 49.6% (n = 5 8), superior mesenteric artery in 43.6% (n = 51), and inferior mesenteric artery in 2.6% (n = 3). After diagnosis of SAM, aspirin was prescribed in 60.7% (n = 71). Statins were prescribed in 29.9% (n = 35). Antihypertensive medications were prescribed in 65% (n = 76), including beta blockers in 42.7% (n = 50); 40.2% (n = 47) of patients were prescribed anticoagulation. Interventions were performed in 26 (22%) patients; 13 had endovascular intervention only, 9 open surgery only, and 4 open and endovascular interventions. Of the 17 patients undergoing endovascular intervention, 19 procedures were performed, most commonly embolization (78.9% [n = 15]), followed by stenting (10.5% [n = 2]). Of the 13 patients undergoing open surgery, 14 procedures were performed, including arterial bypass (50% [n = 7]) and splenectomy with aneurysm ligation (15.4% [n = 2]). Other surgery involved thrombectomy (21.4% [n = 3]) and angioplasty (14.3% [n = 2]). Only 11.5% (n = 3) experienced a perioperative complication, including one hematoma, one abscess, and one death secondary to ongoing hemorrhage. Follow-up imaging was performed in 96.6% (n = 112). Mean follow-up was 1258 days (range, 2-5017 days). Of these, 27.7% (n = 31) had regression, 43.8% (n = 49) stability, and 28.6% (n = 32) progression. Average time between initial diagnosis and progression was 666 days. CONCLUSIONS: SAM is an uncommon disease that may require intervention; it is therefore important that the vascular surgery community be aware of this disease. Follow-up imaging is required to monitor for disease progression.

Safety and effectiveness of transsplenic access for portal venous interventions: a single-center retrospective study.

PURPOSE: To assess the safety and effectiveness of percutaneous transsplenic access (PTSA) for portal vein (PV) interventions among patients with PV disease. MATERIALS AND METHODS: Adult patients with PV disease were enrolled if they required percutaneous catheterization for PV angioplasty, embolization, thrombectomy, variceal embolization, or transjugular intrahepatic portosystemic shunt (TIPS) placement for a difficult TIPS or recanalization of a chronically occluded PV. The procedures were performed between January 2018 and January 2023. Patients were excluded if they had an active infection, had a chronically occluded splenic vein malignant infiltration of the needle tract, had undergone splenectomy, or were under age 18 years. RESULTS: Thirty patients (15 women, 15 men) were enrolled. Catheterization of the PV through PTSA succeeded for 29 of 30 patients (96.7%). The main adverse effect recorded was flank pain in 5 of 30 cases (16.7%). No bleeding events from the spleen, splenic vein, or percutaneous access point were recorded. Two cases (6.7%) each of hepatic bleeding and rethrombosis of the PV were reported, and a change in hemoglobin levels (mean [SD], - 0.5 [1.4] g/dL) was documented in 14 cases (46.7%). CONCLUSION: PTSA as an approach to accessing the PV is secure and achievable, with minimal risk of complications. Minimal to no bleeding is possible by using tract closure methods.

Transjugular intrahepatic portosystemic shunt-induced hemolysis in a non-cirrhotic patient: a case report.

BACKGROUND: In the 1990s, transjugular intrahepatic portosystemic shunts (TIPS) were performed using bare metal stents, and stent-induced hemolysis was a complication noted in 10% of patients. This was due to the mechanical stress created by turbulent flow from the uncovered interstices. Polytetrafluoroethylene (PTFE) stents came into regular use in the early 2000s becoming the standard equipment for TIPS placements, which are predominately covered. Due to this, stent-induced hemolysis has become a rare phenomenon. CASE PRESENTATION: We describe a case of TIPS-induced hemolysis in a 53-years-old Caucasian female patient without cirrhosis. The patient had a history of heterozygous factor 5 Leiden mutation and abnormal lupus anticoagulant profile with development of a portal vein thrombus. She had undergone previous TIPS placement complicated by a TIPS thrombosis 3 years after initial placement requiring venoplasty and extension of the stent. Within one month, the patient developed hemolytic anemia with extensive evaluation that did not yield an alternative cause. Due to temporal association and clinical symptoms, the hemolytic anemia was attributed to the recent TIPS revision. CONCLUSION: This particular case of TIPS-induced hemolysis in a patient who does not have cirrhosis has not been previously described in the literature. Our case highlights that TIPS-induced hemolysis should be considered in anyone who could have potential underlying red blood cell dysfunction, not just those with cirrhosis. Further, the case demonstrates an important point that mild hemolysis (i.e., not requiring blood transfusion) can likely be managed conservatively, without stent removal.

Ultrasound-Guided Phrenic Nerve Block for Lung Nodule Biopsy: Single-Center Initial Experience.

RATIONALE AND OBJECTIVES: Biopsy of lung nodules in the lower lung fields can be difficult because of breathing motion. Ipsilateral phrenic nerve block (PNB) before biopsy should make the biopsy safer, easier, and more precisely targeted. We describe the use of ultrasound-guided PNB before lung nodule biopsy, including relevant anatomy and variations, complications, and technique, along with our first 40 cases. MATERIALS AND METHODS: We retrospectively reviewed patients who underwent PNB before computed tomography (CT)- or ultrasound-guided lung nodule biopsy from April 2015 through March 2020. Patient demographics, CT fluoroscopy time, radiation dose, complications, diagnostic yield, and effectiveness of PNB were recorded. Effectiveness of PNB was based on direct observation of diaphragmatic motion. Control group data for biopsies during the same time frame were collected and matched with nodules ≤1 cm from the PNB group. RESULTS: Among 40 patients identified, no complications occurred related to the PNB. Mean (SD) nodule size was 12.4 (6.2) mm. True-positive results were obtained in 39 patients (98%), with 1 false-negative after an ineffective PNB. PNB was effective in 70%. When CT fluoroscopy was used for the biopsy, radiation dose was significantly lower after an effective PNB than an ineffective PNB (p < .001). Effective PNB was significantly more common with injection of ≥4 mL of local anesthetic (p = .01). Comparison with 19 matched controls showed significantly fewer instances of pneumothorax (p = .02) and greater diagnostic success (p = .03) for the PNB group. CONCLUSION: Ultrasound-guided PNB is safe and effective and can improve outcomes when used before lung nodule biopsy.

The minimally invasive management of visceral artery aneurysms and pseudoaneurysms.

OBJECTIVE: Minimally invasive methods (MIMs) are now available for the management of visceral artery aneurysms and pseudoaneurysms (visceral artery aneurysms [VAA]). The purpose of this study was to review our 10-year experience with the MIM of treating VAA. METHODS: All patients evaluated from June 1999 to June 2009 with VAAs were reviewed. Demographics, therapy, and results were analyzed. RESULTS: MIM was attempted in 185 aneurysms in 176 patients. Initial intervention was successful in 98% ofaneurysms. Sixty-three (34%) aneurysms were located in the splenic artery, 56 (30%) in the hepatic, 28 (15%) in the gastroduodenal, 16 (8.6%) in the pancreaticoduodenal, six (3.2%) in the superior mesenteric, four (2.1%) in the gastric, four (2.1%) in the celiac, four (2.1%) in the gastroepiploic, two (1%) in the inferior mesenteric, and one (0.5%) in the middle colic artery. Pseudoaneurysms were more common than true aneurysms (64% vs 36%). Bleeding was the indication for intervention in 86 aneurysms (46%). Initial treatment was successful in 177 aneurysms (98%). Reintervention was required in five (3%) aneurysms within 30 days. Coiling was used alone in 139 aneurysms (75%) and in combination with at least one other technique in 20 (11%) cases. Thirty-day aneurysm-related mortality was 3.4% (six deaths). Five additional deaths occurred during 30-day follow-up, although none was related to complications of the aneurysms (2.8%). CONCLUSIONS: MIM for visceral artery aneurysms can be used alone or in combination to effectively treat VAAs in elective or emergent conditions.

Normal inflammatory markers in giant cell arteritis with long-standing cranial and symptomatic large-vessel involvement.

We report the case of a 78-year-old woman who presented with cardiovascular risk factors and a history of an atypical transient ischaemic attack. She was referred by her primary care physician to the vascular surgery department at our institution for evaluation of progressive weakness, fatigue, arm claudication and difficulty assessing the blood pressure in her right arm. She was being considered for surgical revascularisation, but a careful history and review of her imaging studies raised suspicion for vasculitis, despite her normal inflammatory markers. She was eventually diagnosed with biopsy-proven giant cell arteritis with diffuse large-vessel involvement. Her symptoms improved with high-dose glucocorticoids.

Prostate Artery Embolization-Review of Indications, Patient Selection, Techniques and Results.

Lower urinary tract symptoms (LUTS) due to benign prostatic hypertrophy (BPH) are a very common problem in men ranging from mild urinary symptoms to recurrent urinary tract infections or renal failure. Numerous treatment options are available ranging from conservative medical therapies to more invasive surgical options. Prostate artery embolization (PAE) has emerged as a novel treatment option for this common problem with clinical efficacy comparable to the current surgical gold standard, transurethral resection of the prostate (TURP). PAE offers fewer complications and side effects without a need for general anesthesia or hospitalization. This review discusses the indications for prostate artery embolization in addition to LUTS, patient evaluation in patients with LUTS, PAE technique and clinical results, with an emphasis on efficacy and safety.

Percutaneous Image-Guided Ablation of Lung Tumors.

Tumors of the lung, including primary cancer and metastases, are notoriously common and difficult to treat. Although surgical resection of lung lesions is often indicated, many conditions disqualify patients from being surgical candidates. Percutaneous image-guided lung ablation is a relatively new set of techniques that offers a promising treatment option for a variety of lung tumors. Although there have been no clinical trials to definitively compare its efficacy to those of traditional treatments, lung ablation is widely practiced and generally accepted to be safe and effective. Especially encouraging results have recently emerged for cryoablation, one of the newer ablative techniques. This article reviews the indications, techniques, contraindications, and complications of percutaneous image-guided ablation of lung tumors with special attention to cryoablation and its recent developments in protocol optimization.

Antiplatelet medications: old and emerging therapies.

Antiplatelet medications have been proven to enhance outcomes in patients with cardiovascular disease. The ideal platelet inhibitor would be quick and reversible and would have universal response, an excellent safety profile, and proven benefit. Currently available antiplatelet medications have been demonstrated to have variable patient response. In light of this medication resistance, emerging therapies to inhibit platelet aggregation are under investigation. We review the currently available antiplatelet medications and the current state of these emerging therapies.

Multi-Detector Computed Tomography Imaging Techniques in Arterial Injuries.

Cross-sectional imaging has become a critical aspect in the evaluation of arterial injuries. In particular, angiography using computed tomography (CT) is the imaging of choice. A variety of techniques and options are available when evaluating for arterial injuries. Techniques involve contrast bolus, various phases of contrast enhancement, multiplanar reconstruction, volume rendering, and maximum intensity projection. After the images are rendered, a variety of features may be seen that diagnose the injury. This article provides a general overview of the techniques, important findings, and pitfalls in cross sectional imaging of arterial imaging, particularly in relation to computed tomography. In addition, the future directions of computed tomography, including a few techniques in the process of development, is also discussed.

Quadrilateral Space Syndrome: Diagnosis and Clinical Management.

Quadrilateral space syndrome (QSS) is a rare disorder characterized by axillary nerve and posterior humeral circumflex artery (PHCA) compression within the quadrilateral space. Impingement is most frequently due to trauma, fibrous bands, or hypertrophy of one of the muscular borders. Diagnosis can be complicated by the presence of concurrent traumatic injuries, particularly in athletes. Since many other conditions can mimic QSS, it is often a diagnosis of exclusion. Conservative treatment is often first trialed, including physical exercise modification, physical therapy, and therapeutic massage. In patients unrelieved by conservative measures, surgical decompression of the quadrilateral space may be indicated.