Placenta Accreta Spectrum: The Role of Interventional Radiology in Multidisciplinary Management.

Placenta accreta spectrum is increasing in prevalence and poses significant risks to obstetric patients. This article defines characteristics, diagnosis, management, and outcomes of placenta accreta spectrum, highlighting interventional radiology's role in its management as part of a multidisciplinary approach.

Added Value of Cone-Beam CT to Identify Arterial Supply during Genicular Artery Embolization for Knee Osteoarthritis.

PURPOSE: To evaluate if the addition of cone-beam computed tomography (CT) to digital subtraction angiography (DSA) improves the identification of the genicular arteries during genicular artery embolization (GAE) for knee pain secondary to osteoarthritis (OA). MATERIALS AND METHODS: This single-center study retrospectively analyzed 222 patients who underwent GAE for painful knee OA between May 2018 and April 2022. Intraprocedural cone-beam CT and DSA images were reviewed independently by 2 sets of interventional radiologists. DSA was performed for all patients. Technically adequate cone-beam CT was available for 205 patients (92.3%). The presence of the genicular arteries identified by cone-beam CT and DSA was compared using Φ coefficients. Embolization targets identified by both cone-beam CT and DSA were evaluated against those identified by DSA alone. RESULTS: Genicular arteries with the highest concordance between cone-beam CT and DSA were the inferior lateral (196 vs 198; Φ = 0.3530; P < .0001), superior lateral (197 vs 200; Φ = 0.3060; P < .0001), and superior medial genicular (186 vs 161; Φ = 0.2836; P < .0001) arteries. Cone-beam CT demonstrated higher rates of detection of the inferior medial (195 vs 178; Φ = 0.04573; P = .5150) and median genicular arteries (200 vs 192; Φ = 0.04573; P = .5150). Meanwhile, genicular arteries less frequently identified by cone-beam CT were the descending genicular (197 vs 200; Φ = -0.03186; P = .6502), superior patellar (175 vs 184; Φ = 0.1332; P = .0569), and recurrent anterior tibial (156 vs 186; Φ = 0.01809; P = .7969) arteries. Cone-beam CT in combination with DSA identified 13.4% (372 vs 328) more targets compared to DSA alone. CONCLUSIONS: Based on the results of the current study, cone-beam CT serves as a valuable adjunct for visualizing the genicular arteries during GAE, and together with DSA, it identifies more potential embolization targets.

Use of n-Butyl-2-Cyanoacrylate for Fallopian Tube Embolization via Selective Catheterization in a Rabbit Model: Feasibility Study for Potential Nonsurgical Sterilization.

PURPOSE: To determine whether fallopian tube embolization with n-butyl-2-cyanoacrylate (nBCA) administered via a microcatheter in a rabbit model was technically feasible and resulted in short-term tubal occlusion. MATERIALS AND METHODS: In 10 female New Zealand white rabbits, the 2 cervices were cannulated using a 5-F catheter and hydrophilic guide wire transvaginally. Salpingography confirmed tubal patency bilaterally. A 2.4-F microcatheter was advanced to the distal fallopian tube, and nBCA/ethiodized oil was administered as the microcatheter was withdrawn to fill the length of the tube. A metallic coil was deployed prior to nBCA administration in half of the fallopian tubes. Rabbits were evaluated for tubal occlusion with salpingography at 1 month, followed by euthanasia and histopathologic analysis. Inflammation and fibrosis were graded from 0 (normal) to 3 (severe). RESULTS: Fallopian tube embolization was technically successful in 17 (85%) of 20 fallopian tubes. Thirteen (76%) of 17 embolized fallopian tubes were occluded at 1 month on salpingography (nBCA only, 7/9; nBCA and coil, 6/8). On histopathologic analysis, direct or indirect evidence of occlusion was observed in 14 (82%) of 17 fallopian tubes. Mild or early fibrosis was observed in 65% of the tubes. The mean inflammation and fibrosis scores for the embolized tubes were 0.62 and 0.94, respectively. CONCLUSIONS: This pilot study demonstrated that embolization of rabbit fallopian tubes using nBCA administered via a microcatheter is technically feasible and results in occlusion of most fallopian tubes in the short term with minimal inflammation. Investigation of efficacy in preventing pregnancy over the long term is warranted.

Using artificial intelligence to risk stratify COVID-19 patients based on chest X-ray findings.

BACKGROUND: Deep learning-based radiological image analysis could facilitate use of chest x-rays as a triaging tool for COVID-19 diagnosis in resource-limited settings. This study sought to determine whether a modified commercially available deep learning algorithm (M-qXR) could risk stratify patients with suspected COVID-19 infections. METHODS: A dual track clinical validation study was designed to assess the clinical accuracy of M-qXR. The algorithm evaluated all Chest-X-rays (CXRs) performed during the study period for abnormal findings and assigned a COVID-19 risk score. Four independent radiologists served as radiological ground truth. The M-qXR algorithm output was compared against radiological ground truth and summary statistics for prediction accuracy were calculated. In addition, patients who underwent both PCR testing and CXR for suspected COVID-19 infection were included in a co-occurrence matrix to assess the sensitivity and specificity of the M-qXR algorithm. RESULTS: 625 CXRs were included in the clinical validation study. 98% of total interpretations made by M-qXR agreed with ground truth (p = 0.25). M-qXR correctly identified the presence or absence of pulmonary opacities in 94% of CXR interpretations. M-qXR's sensitivity, specificity, PPV, and NPV for detecting pulmonary opacities were 94%, 95%, 99%, and 88% respectively. M-qXR correctly identified the presence or absence of pulmonary consolidation in 88% of CXR interpretations (p = 0.48). M-qXR's sensitivity, specificity, PPV, and NPV for detecting pulmonary consolidation were 91%, 84%, 89%, and 86% respectively. Furthermore, 113 PCR-confirmed COVID-19 cases were used to create a co-occurrence matrix between M-qXR's COVID-19 risk score and COVID-19 PCR test results. The PPV and NPV of a medium to high COVID-19 risk score assigned by M-qXR yielding a positive COVID-19 PCR test result was estimated to be 89.7% and 80.4% respectively. CONCLUSION: M-qXR was found to have comparable accuracy to radiological ground truth in detecting radiographic abnormalities on CXR suggestive of COVID-19.

Uterine Artery Embolization for Uterine Fibroids: A Closer Look at Misperceptions and Challenges.

Uterine artery embolization (UAE) has been shown to be a safe and effective treatment for symptomatic uterine fibroids, with over 25 years of supporting data. Although UAE is a well-established treatment option, several misperceptions exist that may limit the number of patients who are considered candidates for UAE. There are also challenges that may affect the ability of interventional radiologists to effectively treat some patients and offer the best possible experience. This article will discuss these misperceptions and challenges, which represent opportunities for further growth and innovation that will allow interventional radiologists to better serve this patient population.

Embolization of uterine arteriovenous malformation causing postpartum hemorrhage using n-butyl cyanoacrylate: A case report.

Uterine artery arteriovenous malformations (AVMs) are rare anomalies that may result in uterine hemorrhage. A 40-year-old G8P5126 woman presented with severe vaginal bleeding and an estimated 2000 mL of blood loss at home. Three weeks prior, she had a vaginal delivery of a term infant resulting in post-partum hemorrhage, with 2700 mL of blood loss. The patient had a history of ectopic pregnancy, placenta previa, and dilatation and curettage. Interventional radiology was consulted, and the patient underwent angiography of the internal iliac and uterine arteries revealing the presence of a uterine AVM, which was successfully embolized using a thick mixture of n-butyl cyanoacrylate and lipiodol. The patient experienced no further episodes of bleeding and was discharged within 24 hours. Recognition of typical symptoms and risk factors for uterine arteriovenous malformations can facilitate early diagnosis and appropriate treatment.

Initial experience with HydroPearl microspheres for uterine artery embolization for the treatment of symptomatic uterine fibroids.

BACKGROUND: Uterine Artery Embolization (UAE) is a minimally invasive procedure used to treat symptomatic uterine fibroids. The HydroPearl Microsphere (Terumo Interventional Systems) is an embolic agent approved for UAE and other embolization procedures. The purpose of this article is to describe our initial experience with HydroPearl for UAE in patients with symptomatic uterine fibroids. Twenty-one patients who underwent UAE using HydroPearl Microspheres at a single institution from May 1, 2018 to December 31, 2019 were included in the study. The electronic medical record (EMR) was reviewed for documentation of short- and long-term complications, as well as improvements in menorrhagia and bulk-type symptoms. We also describe unique attributes of the HydroPearl Microsphere that should be considered when utilizing this embolization particle for UAE. RESULTS: Of the 21 patients, 18 had a 3-month or later post-procedure follow-up documented in the EMR and were included in the analysis. The average time between the UAE procedure and the most recent clinical note was 145 days. Sixteen patients reported symptoms of menorrhagia and 13 reported bulk symptoms prior to the UAE procedure. On follow-up, 13/16 patients (81%) and 12/13 patients (92%) experienced improvement in menorrhagia and bulk symptoms, respectively. The only recorded complication was amenorrhea in 4 patients (22%) who had an average age of 51 years. CONCLUSIONS: Several characteristics of HydroPearl Microsphere may prove helpful when considering these embolic particles for use in UAE. Our initial experience with this embolic agent suggest that the reatment response for menorrhagia and bulk symptoms are largely similar to success rates reported in the literature for other embolic agents. Larger studies are needed to evaluate the safety and efficacy of this embolic particle for this indication.

Ureteroarterial fistula embolization by transradial approach: A case report.

Ureteroarterial fistula is a rare condition wherein a communication develops between a ureter and the common, internal, or external iliac artery. Localizing the fistula can be difficult, as cystoscopy, CT angiography, and conventional angiography have low sensitivity in identifying the fistula. Provocative maneuvers within the ureter, however, can aid in the visualization of fistulae on angiography. Prior reports of endovascular repair have utilized transfemoral access, which makes performing concurrent provocative maneuvers in the ureter challenging. We present a case of successful endovascular ureteroarterial fistula localization and embolization in an 80-year-old woman with recurrent gross hematuria by the transradial approach, aided by concurrent provocative maneuvers performed via cystoscopy. The transradial endovascular approach facilitated a multi-disciplinary joint procedure that resulted in effective treatment of the patient.

Ultrasound-Guided Chemical Component Separation with Botulinum Toxin A prior to Surgical Hernia Repair.

US-guided chemical component separation (CCS) of the abdominal musculature using botulinum toxin A can facilitate the surgical repair of large or complex hernias. Eight patients (2 women and 6 men with median age of 54 years [range, 34-78 years]) underwent preoperative US-guided CCS with hydrodissection before planned surgical repair of large or complex ventral (n = 4), inguinal (n = 2), and flank (n = 2) hernias by 2 interventional radiologists. Technical success rate of US-guided CCS procedures was 100%, and all patients achieved surgical closure a mean 34.1 days (range, 14-48 days) after US-guided CCS.

Superior Hypogastric Nerve Block for Pain Control after Uterine Artery Embolization: Effect of Addition of Steroids on Analgesia.

Superior hypogastric nerve block (SHNB) decreases pain and use of narcotic pain medication following uterine artery embolization (UAE). The purpose of this retrospective study was to evaluate the effect of the addition of a corticosteroid (triamcinolone) to SHNB on analgesia following UAE. Records of 16 patients were reviewed for when pain occurred or acutely worsened after the procedure. No major complications were identified. Patients reported that pain began or worsened an average of 33.8 hours after the procedure, when their average pain increased from 0.6/10 to 5.9/10 (P < .001). This suggests that addition of triamcinolone to SHNB could result in prolonged analgesia following UAE.

Nerve transfer of the anterior interosseous nerve to the thenar branch of the median nerve - an anatomical and histological analysis.

OBJECTIVE: Nerve transfer has become a vital method in the reconstruction of hand function. Reconstructing the motor function to the thenar musculature has proven to be difficult and is rarely satisfactory following direct anatomic repair. The aim of this investigation was to describe the anatomic results obtained by transferring the anterior interosseous nerve to the thenar branch of the median nerve and analyze the histomorphometric results. MATERIAL AND METHODS: Nerve transfers were performed in 15 fresh anatomic specimens. Nerve samples were excised from 13 fresh specimens and histologically investigated. The nerve diameter, fascicle number, and cross-sectional area of the individual fascicles were measured. RESULTS: The results of this investigation revealed that the anterior interosseous nerve and the thenar branch of the median nerve could be identified at their expected locations and a tension-free coaptation could be achieved. The anterior interosseous branch had a mean number of 606 ± 254 axons vs. 2160 ± 1326 in the thenar branch (p < 0.001). The anterior interosseous branch had a mean density of axons per fascicle mm2 of 2398 ± 829 vs. 3012 ± 740 in the thenar branch (p = 0.390). The ratio of axons between the thenar branch of the median nerve and the anterior interosseous nerve yielded a mean of 1:4.16. CONCLUSION: Nerve transfer of the anterior interosseous nerve to the thenar branch of the median nerve should be considered as a viable option but remains a subject of investigation owing to its critical axon ratio. Furthermore, larger clinical studies will be required to validate or neglect this nerve transfer.

Magnetic resonance imaging and clinical features of glenoid labral flap tears.

OBJECTIVE: Displaced flaps of glenoid labral tissue are an uncommonly encountered finding on MRI of the shoulder, and are of unclear clinical significance. The purpose of this study is to describe the imaging characteristics of displaced glenoid labral flaps, evaluate for any common concomitant injuries, and identify the typical clinical presentation and management of patients with this lesion. MATERIALS AND METHODS: This retrospective, observational study was approved by the institutional review board. Nineteen patients with flap-type tears of the labrum on preoperative MRI were identified. Each examination was retrospectively reviewed by two radiologists for size, location, and signal intensity of the displaced flap of tissue, in addition to any co-existing labrum or cartilage pathological conditions and clinical information. RESULTS: All displaced flaps extended from the inferior margin of the glenoid into the axillary recess. The average size of the visualized flap was 10.9 by 6.0 by 2.6 mm. Seventy percent of the flaps had signal intensity isointense to labrum and hypointense to hyaline cartilage on T2-weighted images. All 19 patients had concomitant labral pathological conditions and 63% had cartilage defects, visualized on MRI. Clinical evidence of shoulder instability was seen in 83% of patients, and 67% were managed surgically. CONCLUSION: Glenoid labral flap tears have distinct imaging characteristics that may aid in their identification. Their presence should prompt careful evaluation of the glenoid articular cartilage. Recognition of a labral flap tear may have clinical importance, as 83% of patients with this finding demonstrated clinical evidence of shoulder instability, often requiring surgical intervention.

Creation of an Extraluminal Arterial Bypass Graft Using a Commercially Available Self-Expanding Stent Graft: Feasibility Study in a Porcine Model.

PURPOSE: The purpose of this study was to assess the technical feasibility of ultrasound-guided endovascular creation of a percutaneous extraluminal arterial bypass graft without a surgically created arterial anastomosis. MATERIALS AND METHODS: Nine swine were utilized for this IACUC-approved study using a carotid bypass model in swine. Using sonographic guidance, percutaneous access was obtained to the proximal and distal common carotid artery. A self-expanding stent graft was advanced through the proximal carotid access site, tunneled subcutaneously, then advanced through the distal carotid access site, and deployed. The stent grafts were monitored weekly for patency using ultrasound. Angiography was performed at 4 weeks to evaluate for graft patency. Gross pathologic analysis was performed on the explanted stent grafts. RESULTS: In eight out of the nine swine (89%), percutaneous extraluminal bypass graft creation was technically successful, with brisk flow through the stent graft to the distal circulation, complete exclusion of the bypassed segment of carotid artery, and no extravasation. The technical failure was due to stent graft maldeployment. Of the six swine evaluated for patency, four grafts were patent at the 4-week end point. Both occluded stent grafts were due to extraluminal extrusion of one end, likely related to neck movement and growth in neck length. CONCLUSION: The percutaneous arterial bypass technique had a high technical success rate and a graft patency rate of 67% at 4 weeks, with early occlusions possibly related to limitations of the animal model.

Clinical implications of acute pelvicaliceal hematoma formation during percutaneous catheter nephrostomy insertion.

PURPOSE: To determine the clinical implications of acute pelvicaliceal hematoma formation during percutaneous catheter nephrostomy (PCN) insertion. METHODS: Collecting system hematoma burden was retrospectively assessed for 694 PCN insertions in 502 patients. RESULTS: Pelvicaliceal hematoma formation occurred in 146 kidneys (21%) in 136 patients. Clinically significant blood loss occurred in 3 patients with hematomas within one week compared to 4 patients without hematomas (p=0.39). Twenty-four patients with hematomas underwent catheter exchange within one week, compared to 55 patients without hematomas (p=0.49). CONCLUSION: Pelvicaliceal hematoma formation after PCN insertion is not uncommon and is associated with very rare clinical sequelae.

Sensory reanimation of the hand by transfer of the superficial branch of the radial nerve to the median and ulnar nerve.

BACKGROUND: It remains a surgical challenge to treat high-grade nerve injuries of the upper extremity. Extra-anatomic reconstructions through the transfer of peripheral nerves have gained clinical importance over the past decades. This contribution outlines the anatomic and histomorphometric basis for the transfer of the superficial branch of the radial nerve (SBRN) to the median nerve (MN) and the superficial branch of the ulnar nerve (SBUN). METHODS: The SBRN, MN, and SBUN were identified in 15 specimens and the nerve transfer performed. A favorable site for coaptation was chosen and its location described using relevant anatomical landmarks. Histomorphometric characteristics of donor and target were compared to evaluate the chances of a clinical success. RESULTS: A suitable location for dissecting the SBRN was identified prior to its first bifurcation. Coaptations were possible near the pronator quadratus muscle, approximately 22 cm distal to the lateral epicondyle of the humerus. The MN and SBUN had to be dissected interfasciculary over 82 ± 5.7 mm and 49 ± 5.5 mm, respectively. Histomorphometric analysis revealed sufficient donor-to-recipient axon ratios for both transfers and identified the SBRN as a suitable donor with high axon density. CONCLUSION: Our anatomic and histomorphometric results indicate that the SBRN is a suitable donor for the MN and SBUN at wrist level. The measurements show feasibility of this procedure and shall help in planning this sensory nerve transfer. High axon density in the SBRN identifies it or its branches an ideal candidate for sensory reanimation of fingers and thumbs.

Percutaneous cryoablation of renal masses under CT fluoroscopy: radiation doses to the patient and interventionalist.

PURPOSE: Computed tomographic (CT) fluoroscopy-guided percutaneous cryoablation is an effective therapeutic method used to treat focal renal masses. The purpose of this study is to quantify the radiation dose to the patient and interventional radiologist during percutaneous cryoablation of renal masses using CT fluoroscopic guidance. METHODS: Over a 1-year period, the CT fluoroscopy time during percutaneous cryoablation of renal masses was recorded in 41 patients. The level of complexity of each procedure was designated as simple, intermediate, or complex. Patient organ radiation doses were estimated using an anthropomorphic model. Dose to the interventional radiologist was estimated using ion chamber survey meters. RESULTS: The average CT fluoroscopy time for technically simple cases was 47 s, 126 s for intermediate cases, and 264 s for complex cases. The relative risk of hematologic stomach and liver malignancy in patients undergoing this procedure was 1.003-1.074. The lifetime attributable risk of cancer ranged from 2 to 58, with the highest risk in younger patients for developing leukemia. The estimated radiation dose to the interventionalist without lead shielding was 390 mR (3.9 mGy) per year of cases. CONCLUSIONS: The radiation risk to the patient during CT fluoroscopy-guided percutaneous renal mass cryoablation is, as expected, related to procedure complexity. Quantification of patient organ radiation dose was estimated using an anthropomorphic model. This information, along with the associated relative risk of malignancy, may assist in evaluating risks of the procedure, particularly in younger patients. The radiation dose to the interventionist is low regardless of procedure complexity, but highlights the importance of lead shielding.

Tunneled peritoneal drainage catheter placement for refractory ascites: single-center experience in 188 patients.

PURPOSE: To assess the success and safety of tunneled peritoneal drainage catheters for the management of ascites refractory to medical management. MATERIALS AND METHODS: A total of 188 consecutive patients (83 male, 105 female; average age 59 y) with refractory ascites were treated with tunneled peritoneal drainage catheters from January 1, 2006, to August 10, 2012. A combination of fluoroscopic and ultrasound guidance was used to insert all catheters. Patient history, procedural records, and clinical follow-up documents were retrospectively reviewed. Clinical data (malignancy, renal disease, chemotherapy, neutropenia, albumin levels) were compared with respect to patency and complication rates with the use of odds ratios. Catheter survival curves were generated with the Kaplan-Meier method and life-table analysis for the cumulative and infection-free survival of primary and secondary catheters. RESULTS: A total of 193 catheter placements or interventions were performed in 188 patients with refractory ascites: 170 catheters (93%) were placed for malignant etiologies and 13 (7%) for nonmalignant etiologies. The most common malignancies were ovarian (22%), pancreatic (12%), and breast (11%). The most common nonmalignant etiologies were end-stage liver disease (n = 7) and heart failure (n = 6). There was a 100% technical success rate for catheter insertion; no procedure-related deaths or major placement complications were identified. Catheter survival ranged from 0 to 796 days (mean, 60 d), with a total of 11,936 cumulative catheter-days. Fourteen postplacement complications were identified: five patients experienced catheter malfunction, four had leakage of ascites at the incisional site requiring suture placement, three had cellulitis of the tunnel tract, and two developed peritonitis. The annual complication event rate was 0.43 events per year (ie, 0.12 events per 100 catheter-days). Pancreatic malignancy was associated with a significantly increased rate of catheter malfunction (ie, occlusion). CONCLUSIONS: Radiologic insertion of tunneled peritoneal drainage catheters demonstrated a 100% technical success rate for insertion and an acceptable complication rate for the management of refractory ascites.