Incidental deep venous thrombosis diagnosed on lower extremity computed tomography is a rare but clinically impactful finding.

BACKGROUND: In the setting of a known thrombotic event, computed tomography (CT) studies provide reasonable sensitivity for the diagnosis of deep venous thrombosis (DVT). However, the incidence and accuracy of a DVT diagnosis on CT studies not targeted for the detection of DVT are not well described. In addition, the clinical impact of DVTs incidentally identified on CT is unknown. METHODS: In this single-institution retrospective study, we queried all contrasted CT studies of the lower extremities performed over a 10-year period. Regular expressions applied to the radiology reports associated with the CT studies identified studies with positive findings associated with DVT. These selected reports were then manually reviewed to confirm the presence of a DVT. Patient demographics and relevant medical and surgical history were obtained through a chart review. Follow-up information was obtained for 1 year after the incident CT and included treatment course, additional imaging, and adverse events. An incidental DVT was one identified in a patient in whom the DVT was not noted in a prior study and for whom the study indication did not include concern for DVT or pulmonary embolism. RESULTS: Of 16,637 lower extremity contrasted CT studies queried, 37 study reports identified a DVT. However, only 13 patients had a finding of an incidental DVT (10-year incidence of 0.08%). Among these 13 patients, 11 underwent additional imaging, including 9 who had a subsequent venous duplex and 2 who had subsequent CT studies. Among those with a subsequent duplex, DVT was not identified in eight cases, whereas in one case, DVT was confirmed. Among those with subsequent CT studies, DVT was not identified in one case and was confirmed in one case. Of the 13 patients with incidental DVTs, 3 were initiated on anticoagulation based on their initial CT findings alone. Among these, two did not experience any complications from their DVT or anticoagulation regimen. One did experience major bleeding complications, requiring additional procedures. CONCLUSIONS: Incidental DVTs are a rare finding in lower extremity CT studies, noted to occur in only 0.08% of studies. Most patients with incidental DVTs receive additional imaging, with negative findings in 80% of cases. This study identified that 23% of patients were initiated on anticoagulation due to the CT findings, with a 33% rate of significant complications. Currently, a CT venogram is not recommended as a first-line modality for the diagnosis of DVT. However, there is no guidance regarding the need for repeat imaging in patients with incidentally diagnosed lower extremity DVTs identified on CT. Additional study is needed to provide evidence for guideline development.

Incidence, Presentation, and Natural History of Adrenal Hemorrhage: An Institutional Analysis.

INTRODUCTION: Adrenal hemorrhage (AH) can occur due to multiple etiologies with variable radiographic appearance, often indistinguishable from underlying adrenal neoplasms. There is a lack of AH literature and evidence-based guidelines. Our study aimed to understand the prevalence and etiology of AH, follow-up, and incidence of underlying neoplasm. METHODS: An institutional database was queried from January 2006 to October 2021 for patients with AH on imaging, excluding patients with known malignancies, adrenal masses, or prior adrenal surgery. Demographics, medical history, hematoma size, laterality, biochemical evaluation, intervention, and additional imaging were reviewed. RESULTS: Of 490,301 imaging reports queried, 530 (0.11%) with AH met inclusion criteria. Most imaging (n = 485, 91.5%) was performed during trauma evaluation. Two patients underwent dedicated intervention at presentation. Interval imaging was performed in 114 (21.5%) patients at a median of 2.6 (interquartile range 0.99-13.4) mo, with resolution (n = 84, 73.7%) or decreased size of AH (n = 21, 18.4%) in most patients. Only 10 patients (1.9%) saw an outpatient provider in our system to address AH or evaluate for underlying mass, and 9 (1.7%) underwent biochemical screening. Thirteen patients (11% of 118 patients with any follow-up) had evidence of an adrenal mass, confirmed on serial imaging (n = 10) or adrenalectomy (n = 3). Scans performed for nontrauma indications were significantly more likely to have an underlying mass (n = 6/26 [23.1%]) than those performed for trauma evaluation (n = 7/92 [7.6%], P = 0.04). CONCLUSIONS: AH is a rare finding associated with an increased rate of underlying adrenal mass, particularly when unrelated to trauma. Most AH resolves spontaneously without intervention. Follow-up imaging at 6 mo can help distinguish mass-associated AH from simple hemorrhage.

Alternate Cervical Venous Access Sites for Implantable Port Catheters: Experience at a Single Quaternary Care Institution.

INTRODUCTION: Clinical outcomes of implantable port catheters (IPCs) placed via alternative veins such as the external jugular and cervical collaterals have not been well established. This investigation evaluates the short- and long-term outcomes of IPCs inserted via alternate cervical veins (ACV) compared to traditionally inserted IPCs via the internal jugular vein (IJV). MATERIALS AND METHODS: A total of 24 patients who received an IPC between 2010 and 2020 via an ACV-defined as the external jugular vein, superficial cervical vein, or unnamed collateral veins-were identified. Based on power analysis, a matched control group of 72 patients who received IPCs via the IJV was identified. Non-inferiority analysis for port complications was performed between the two groups based on the selected non-inferiority margin of 20%. Secondary end points included complication-free survival and comparison of complications by the time at which they occurred. RESULTS: ACV access was non-inferior to traditional access for overall complications. Alternate access resulted in fewer complications than traditional access with an estimated reduction of - 7.0% [95% CI - 23.6%, 39.7%]. There was no significant difference in peri-procedural and post-procedural complications between the two groups. Complication-free survival was also equivalent between the two groups. CONCLUSION: IPC placement via ACVs was non-inferior to IPCs placed via traditional access through the IJV. When abnormal pathology obviates the use of IJV access, other cervical veins may be considered prior to seeking alternate locations such as femoral, translumbar, inferior vena cava, and hepatic veins.

Subclavian Effort Thrombosis: Pathophysiology, Diagnosis, and Management.

Subclavian vein (SCV) effort thrombosis, also known as Paget-Schroetter syndrome or venous thoracic outlet syndrome, is an uncommon condition that affects individuals with an irregularly narrow thoracic outlet who engage in repetitive overhead motions of the affected arm. Venous injury arises from microtraumas that occur from the repetitive compression of the SCV between the first rib and the overlying clavicle. Additional sources of extrinsic compression can be due to the anterior scalene muscle, subclavius muscle, and costoclavicular ligament. SCV effort thrombosis is a distinct entity from other forms of deep venous thrombosis and requires unique diagnostic and treatment considerations. Early catheter-directed therapy in the form of pharmacomechanical or catheter-directed thrombolysis combined with prompt surgical thoracic outlet decompression offers patients the best chances for early and durable symptom relief.

Comparative Oncology: Management of Hepatic Neoplasia in Humans and Dogs.

Primary hepatic neoplasia is uncommonly reported in dogs. Hepatocellular carcinoma (HCC) is the most frequent neoplasia identified in dogs and considerable effort has been committed towards identifying definitive and palliative treatment options. HCC is well recognized in humans as a sequelae of liver disease such as hepatitis or cirrhosis, while in dogs a similar link has failed to be fully elucidated. Management of HCC in people may be curative or palliative dependent on staging and transplant eligibility. Despite differences in etiology, there is substantial similarity between treatment options for liver neoplasia in human and veterinary medicine. The below summary provides a comparative discussion regarding hepatic neoplasia in dogs and people with a specific focus on HCC. Diagnosis as well as descriptions of the myriad treatment options will be reviewed.

Erratum: Subclavian Effort Thrombosis: Pathophysiology, Diagnosis, and Management.

[This corrects the article DOI: 10.1055/s-0042-1753481.].

A Survey of Interventional Radiologists Regarding the Use of Morbidity and Mortality Conferencing in Departmental Quality Improvement Programs.

PURPOSE: To investigate the degree to which morbidity and mortality (M&M) conferencing is utilized in interventional radiology (IR), identify impediments to its adoption, and assess the experience of those using this tool. MATERIALS AND METHODS: Members of the Society of Interventional Radiology (SIR) were offered a 9-question survey of practices and experiences regarding M&M conferencing within their quality assessment (QA) programs. RESULTS: Among 604 respondents, 37.8% were university-based practitioners and 60% were from outside of university practices. Of all respondents, 43% reported practicing 100% IR, with 28.5% practicing IR 75%-99% and 11% practicing IR <50% of the time. The use of M&M conferencing was significantly greater in university practices (90.7%) than in nonuniversity practices (37.1%) and among practitioners performing at least 75% IR (71.2%) than among those practicing <75% (28.8%). The conferences were held monthly (66.6%) or more often, and the majority (56%) of the events identified were scored using the SIR severity score. Approximately 20% of M&M conferences were multidisciplinary, shared most commonly with vascular surgery. The reasons cited for not using M&M included the lack of time and the logistical challenges of the process. However, among those who participate in M&M conferences, the QA goals of the conference were met at very high rates. CONCLUSIONS: M&M conferencing is well established in university IR programs and among full-time practitioners but much less so elsewhere. For those sites that do not utilize M&M conferencing, there may be a considerable benefit to addressing the obstacles that are limiting their implementation of this tool.

Diagnostic performance of lower extremity Doppler ultrasound in detecting iliocaval obstruction.

OBJECTIVE: To retrospectively evaluate the performance of two commonly used Doppler ultrasound parameters, namely, venous flow phasicity and response to Valsalva maneuver, in detecting iliocaval obstruction. METHODS: All imaging studies of patients seen by interventional radiology for lower extremity venous disease at a single institution from 1996 to 2018 were retrospectively identified. Lower extremity ultrasounds with a concurrent magnetic resonance, computed tomography, or conventional venogram performed within the next 7 days, which served as gold standard, were further identified (n = 192 examinations, including 313 limbs). Iliocaval obstruction were assessed by two ultrasound criteria: (1) nonphasic flow and/or (2) nonresponsive flow to Valsalva in the common femoral vein. The sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) for diagnosing iliocaval obstruction were calculated for each ultrasound criterion, and also for when the two criteria were assessed jointly. RESULTS: Of the 313 limbs assessed for venous flow phasicity, 133 (42.5%) had an iliocaval obstruction confirmed on subsequent venography. Nonphasic flow demonstrated a sensitivity of 69.2%, specificity of 82.8%, NPV of 78.4%, and PPV of 74.8% for diagnosing iliocaval obstruction. Of the 212 limbs assessed for Valsalva response, 88 (41.5%) had a confirmed iliocaval obstruction. Nonresponsive flow to Valsalva demonstrated a sensitivity of 13.6%, specificity of 97.6%, NPV of 61.6%, and PPV of 80.0% for diagnosing iliocaval obstruction. Joint assessment using phasicity and Valsalva criteria demonstrated a sensitivity of 68.2%, specificity of 87.2%, NPV of 79.6%, and PPV of 78.9%. CONCLUSIONS: In this tertiary care setting, Doppler ultrasound examination was not a reliable diagnostic tool for detecting iliocaval obstruction.

MR-Compatible Haptic Display of Membrane Puncture in Robot-Assisted Needle Procedures.

Multilayer electroactive polymer films actuate a small hand-held device that can display tool tip forces during MR-guided interventions. The display produces localized skin stretch at the thumb and index fingertips. Tests confirm that the device does not significantly affect MR imaging and produces detectable stimuli in response to forces measured by a biopsy needle instrumented with optical fibers. Tests with human subjects explored robotic and teleoperated paradigms to detect when the needle contacted a membrane embedded at variable depth in a tissue phantom that approximated the properties of porcine liver. In the first case, naive users detected membranes with a 98.9% success rate as the needle was driven at fixed speed. In the second case, users with experience in needle-based procedures controlled the needle insertion and detected membranes embedded in tissue phantoms with a 98% success rate. In the second experiment, some users detected membranes with very light contact forces, but there was greater subject-to-subject variation.

Endovascular Management of May-Thurner Syndrome in Adolescents: A Single-Center Experience.

PURPOSE: To report a single-center experience in regard to the technique, safety, and clinical outcomes of endovascular therapy for treatment of May-Thurner syndrome (MTS) in adolescent patients. MATERIALS AND METHODS: A retrospective review identified 10 patients (6 female; mean age, 16 y; range, 12-18 y; mean weight, 73 kg; range, 50-116 kg) treated by endovascular therapy for MTS from 1998 to 2015. Clinical presentations consisted of acute thrombotic MTS (n = 6) and nonthrombotic MTS (n = 4). Catheter-directed thrombolysis was performed in all cases of thrombosis. Venoplasty and stent placement were performed in all cases. Self-expanding stents 12-16 mm in diameter and 4-9 cm in length were deployed. RESULTS: No major periprocedural complications were observed. Median follow-up was 32 months (range, 6-109 mo). Primary and secondary patency rates were 79% and 100% at 12 months and 79% and 89% at 36 months, respectively. In a single patient with permanent loss of flow in the treated segment, multiple risk factors for thrombosis were identified. Rates of posttreatment symptoms were 0% by Villalta score and 60% (n = 6; mild symptoms) by modified Villalta score at the last clinical follow-up. CONCLUSIONS: Endovascular therapy for the treatment of MTS in our adolescent cohort was safe and effective in relieving venous obstruction. Stent placement in patients with underlying thrombophilic disorders is associated with loss of secondary patency, suggesting the need for further consideration in this population.

Electromagnetic navigation with multimodality image fusion for image-guided percutaneous interventions.

Percutaneous image-guided interventions are performed for a variety of clinical indications: to obtain tissue biopsies, to alleviate pain, and to treat diseases including a variety of malignancies. The efficacy of all of the above is directly related to accurate positioning of the procedural device using imaging guidance. The ability to achieve accurate positioning can be limited by a variety of technical factors including small lesion size, a lesion that is best seen on an imaging modality that is impractical for guiding intervention, and a lesion that is difficult to access or in a tenuous location. Electromagnetic navigation with image fusion has the ability to improve the speed and accuracy of percutaneous image-guided interventions by providing real-time feedback and allowing image overlay of diagnostic-imaging modalities with the guiding modality. The article discusses the technical aspects of electromagnetic navigation including potential clinical applications, procedures that may be facilitated by navigation, and inherent limitations of the technology.

Design and Coordination Kinematics of an Insertable Robotic Effectors Platform for Single-Port Access Surgery.

Single port access surgery (SPAS) presents surgeons with added challenges that require new surgical tools and surgical assistance systems with unique capabilities. To address these challenges, we designed and constructed a new insertable robotic end-effectors platform (IREP) for SPAS. The IREP can be inserted through a Ø15 mm trocar into the abdomen and it uses 21 actuated joints for controlling two dexterous arms and a stereo-vision module. Each dexterous arm has a hybrid mechanical architecture comprised of a two-segment continuum robot, a parallelogram mechanism for improved dual-arm triangulation, and a distal wrist for improved dexterity during suturing. The IREP is unique because of the combination of continuum arms with active and passive segments with rigid parallel kinematics mechanisms. This paper presents the clinical motivation, design considerations, kinematics, statics, and mechanical design of the IREP. The kinematics of coordination between the parallelogram mechanisms and the continuum arms is presented using the pseudo-rigid-body model of the beam representing the passive segment of each snake arm. Kinematic and static simulations and preliminary experiment results are presented in support of our design choices.

Design and performance evaluation of a minimally invasive telerobotic platform for transurethral surveillance and intervention.

Bladder cancer, a significant cause of morbidity and mortality worldwide, presents a unique opportunity for aggressive treatment due to the ease of transurethral accessibility. While the location affords advantages, transurethral resection of bladder tumors can pose a difficult challenge for surgeons encumbered by current instrumentation or difficult anatomic tumor locations. This paper presents the design and evaluation of a telerobotic system for transurethral surveillance and surgical intervention. The implementation seeks to improve current procedures and enable development of new surgical techniques by providing a platform for intravesicular dexterity and integration of novel imaging and interventional instrumentation. The system includes a dexterous continuum robot with access channels for the parallel deployment of multiple visualization and surgical instruments. This paper first presents the clinical conditions imposed by transurethral access and the limitations of the current state-of-the-art instrumentation. Motivated by the clinical requirements, the design considerations for this system are discussed and the prototype system is presented. Telemanipulation evaluation demonstrates submillimetric RMS positioning accuracy and intravesicular dexterity suitable for improving transurethral surveillance and intervention.