Automating sedation state assessments using natural language processing

INTRODUCTION

Common goals for procedural sedation are to control pain and ensure the patient is not moving to an extent that is impeding safe progress or completion of the procedure. Clinicians perform regular assessments of the adequacy of procedural sedation in accordance with these goals to inform their decision-making around sedation titration and also for documentation of the care provided. Natural language processing could be applied to real-time transcriptions of audio recordings made during procedures in order to classify sedation states that involve movement and pain, which could then be integrated into clinical documentation systems. The aim of this study was to determine whether natural language processing algorithms will work with sufficient accuracy to detect sedation states during procedural sedation.

DESIGN

A prospective observational study was conducted.

METHODS

Audio recordings from consenting participants undergoing elective procedures performed in the interventional radiology suite at a large academic hospital were transcribed using an automated speech recognition model. Sentences of transcribed text were used to train and evaluate several different NLP pipelines for a text classification task. The NLP pipelines we evaluated included a simple Bag-of-Words (BOW) model, an ensemble architecture combining a linear BOW model and a "token-to-vector" (Tok2Vec) component, and a transformer-based architecture using the RoBERTa pre-trained model.

RESULTS

A total of 15,936 sentences from transcriptions of 82 procedures was included in the analysis. The RoBERTa model achieved the highest performance among the three models with an area under the ROC curve (AUC-ROC) of 0.97, an F1 score of 0.87, a precision of 0.86, and a recall of 0.89. The Ensemble model showed a similarly high AUC-ROC of 0.96, but lower F1 score of 0.79, precision of 0.83, and recall of 0.77. The BOW approach achieved an AUC-ROC of 0.97 and the F1 score was 0.7, precision was 0.83 and recall was 0.66.

CONCLUSION

The transformer-based architecture using the RoBERTa pre-trained model achieved the best classification performance. Further research is required to confirm the that this natural language processing pipeline can accurately perform text classifications with real-time audio data to allow for automated sedation state assessments.

CLINICAL RELEVANCE

Automating sedation state assessments using natural language processing pipelines would allow for more timely documentation of the care received by sedated patients, and, at the same time, decrease documentation burden for clinicians. Downstream applications can also be generated from the classifications, including for example real-time visualizations of sedation state, which may facilitate improved communication of the adequacy of the sedation between clinicians, who may be performing supervision remotely. Also, accumulation of sedation state assessments from multiple procedures may reveal insights into the efficacy of particular sedative medications or identify procedures where the current approach for sedation and analgesia is not optimal (i.e. a significant amount of time spent in "pain" or "movement" sedation states).

An Introductory Guide to Artificial Intelligence in Interventional Radiology: Part 1 Foundational Knowledge

Artificial intelligence (AI) is rapidly evolving and has transformative potential for interventional radiology (IR) clinical practice. However, formal training in AI may be limited for many clinicians and therefore presents a challenge for initial implementation and trust in AI. An understanding of the foundational concepts in AI may help familiarize the interventional radiologist with the field of AI, thus facilitating understanding and participation in the development and deployment of AI. A pragmatic classification system of AI based on the complexity of the model may guide clinicians in the assessment of AI. Finally, the current state of AI in IR and the patterns of implementation are explored (pre-procedural, intra-procedural, and post-procedural).

An Introductory Guide to Artificial Intelligence in Interventional Radiology: Part 2: Implementation Considerations and Harms

The introduction of artificial intelligence (AI) in interventional radiology (IR) will bring about new challenges and opportunities for patients and clinicians. AI may comprise software as a medical device or AI-integrated hardware and will require a rigorous evaluation that should be guided based on the level of risk of the implementation. A hierarchy of risk of harm and possible harms are described herein. A checklist to guide deployment of an AI in a clinical IR environment is provided. As AI continues to evolve, regulation and evaluation of the AI medical devices will need to continue to evolve to keep pace and ensure patient safety.

Treatment of adenomyosis, abdominal wall endometriosis and uterine leiomyoma with interventional radiology: A review of current evidences

Interventional radiology shows promises in the field of women's health, particularly in pelvic interventions. This review article discusses the latest advancements in interventional radiology techniques for pelvic conditions affecting women including adenomyosis, abdominal wall endometriosis and uterine leiomyoma. Extraperitoneal endometriosis involving the abdominal wall may be treated by percutaneous thermal ablation, such as cryoablation, whereas uterine leiomyoma and adenomyosis can be managed either using percutaneous thermal ablation or using uterine artery embolization. Continued research and development in interventional radiology will further enhance the minimally-invasive interventions available for women's health, improving outcomes and quality of life for this large patient population of women.

Real-World Experience With the Angio-Seal Closure Device: Insights From Manufacturer and User Facility Device Experience Database

PURPOSE

Angio-Seal (Terumo Medical Corporations, Somerset, New Jersey) device is indicated for femoral arteriotomy closure. Real-world published data on complications are limited. We present 1 year of safety events involving Angio-Seal from the US Food and Drug Administration's post-market surveillance database of Manufacturer and User Facility Device Experience (MAUDE). Steps for managing frequent device-related problems are discussed.

MATERIALS AND METHODS

Angio-Seal MAUDE data from November 2019 to December 2020 was classified according to (1) mode of device failure, (2) complication, (3) treatment, and (4) Cardiovascular and Interventional Radiological Society of Europe (CIRSE) adverse event classification system.

RESULTS

There were 715 safety events, involving Angio-Seal VIP (93.1%), Evolution (5.7%), STS Plus (1.1%), and sizes 6F (62.5%) and 8F (37.5%). Failure mode involved unrecognized use of a damaged device (43.4%), failed deployment (20.1%), failed arterial advancement (6.3%), detachment of device component (4.9%), failed retraction (3.6%), operator error (1.1%), and indeterminate (20.6%). Of total, 44.8% of events were associated with patient harm. Complications involved minor blood loss (34.1%), hematoma (5.6%), significant blood loss (1.4%), and pseudoaneurysm (1.4%). Of total, 43.3% of cases required manual compression (MC), whereas 8.8% required more advanced intervention. Interventions included surgical repair (49.2%), thrombin injection (9.5%), balloon tamponade (6.3%), covered stent (4.8%), and unspecified (30.2%). Majority of safety events were CIRSE grade 1 (92.0%), followed by grades 2 (3.1%), 3 (4.6%), and 6 (deaths, 0.3%). Minority of devices were returned for manufacturer analysis (27.8%).

CONCLUSIONS

The majority of safety events were associated with minor blood loss or local hematoma and could be addressed with MC alone. Most events were attributed to damaged device; however, very few devices were returned to manufacturer for analysis. This should be encouraged to allow for root cause analysis in order to improve safety profile of devices. System-level strategies for addressing barriers to under-reporting of safety events may also be considered.

CLINICAL IMPACT

Our study highlights important safety events encountered in real-world practice with Angio-Seal closure device. The MAUDE database captures real-world device malfunctions not typically appreciated in conventional clinical trials. Our study provides valuable insight for clinician-users on anticipating and managing the most common device malfunctions. Additionally, our data provide feedback for manufactures to optimize product design and direct manufacturer user training to improve safety. Finally, we hope that the study promotes system-level strategies that foster reporting of safety events and undertaking of root cause analysis.

Utility of 4D CT in endoleak characterization after advanced endovascular aortic repair

OBJECTIVES

To assess the performance of dynamic or 4D CT in characterizing endoleaks in advanced endovascular aortic repair (branched and fenestrated) when other modalities fail to fully characterize the leak, most often conventional CTA.

METHODS

Retrospective review of 13 patients from 2008 to 2021 who underwent 16 4D CTs to characterize endoleaks in branched and fenestrated endovascular aortic repair (FB-EVAR). The 4D CTs were performed covering up to 16 cm of the z-axis, with anywhere between 10 and 40 iterations performed every 2 s. These settings were adjusted depending on graft characteristics and type of endoleak suspected. The scans were assessed for their ability to detect the endoleak (sensitivity), and further to characterize the endoleak by type and subtype (specificity).

RESULTS

Overall sensitivity in 16 scans for endoleak detection was 100%. There was a specificity of 87.5% for determining the type of endoleak (14/16). These results included two studies that were inconclusive and repeated due to technical difficulties. In patients where a specific subtype was not established, the leak was localized to the appropriate target vessel. Average dose for the 4D CT was 4724 mGy*cm (1108-11069), with the outlining higher dose scans secondary to higher iterations in those scans.

CONCLUSIONS

4D CT is a useful adjunctive tool in FB-EVAR surveillance with excellent sensitivity and specificity in characterizing endoleaks. This allows for accurate localization of leaks, which is critical for management planning.

Typology, Severity, and Outcomes of Adverse Events Related to Angiographic Equipment-A Ten-Year Analysis of the FDA MAUDE Database

Purpose: Angiographic equipment is a key component of healthcare infrastructure, used for endovascular procedures throughout the body. The literature on adverse events related to this technology is limited. The purpose of this study was to analyze adverse events related to angiographic devices from the US Food and Drug Administration's Manufacturer and User Facility Device Experience (MAUDE) database. Methods: MAUDE data on angiographic imaging equipment from July 2011 to July 2021 were extracted. Qualitative content analysis was performed, a typology of adverse events was derived, and this was used to classify the data. Outcomes were assessed using the Healthcare Performance Improvement (HPI) and Society of Interventional Radiology (SIR) adverse event classifications. Results: There were 651 adverse events reported. Most were near misses (67%), followed by precursor safety events (20.5%), serious safety events (11.2%), and unclassifiable (1.2%). Events impacted patients (42.1%), staff (3.2%), both (1.2%), or neither (53.5%). The most common events associated with patient harm were intra-procedure system shut down, foot pedal malfunction, table movement malfunction, image quality deterioration, patient falls, and fluid damage to system. Overall, 34 (5.2%) events were associated with patient death; 18 during the procedure and 5 during patient transport to another angiographic suite/hospital due to critical failure of equipment. Conclusion: Adverse events related to angiographic equipment are rare; however, serious adverse events and deaths have been reported. This study has defined a typology of the most common adverse events associated with patient and staff harm. Increased understanding of these failures may lead to improved product design, user training, and departmental contingency planning.

Enhancing preoperative assessment in chronic thromboembolic pulmonary hypertension: A comprehensive analysis of interobserver agreement and proximity-based CT pulmonary angiography scoring

Background

Surgical risk in chronic thromboembolic pulmonary hypertension (CTEPH) depends on the proximity of thromboembolism on CT pulmonary angiography (CTPA). We assessed interobserver agreement for the quantification of thromboembolic lesions in CTEPH using a novel CTPA scoring index.

Methods

Forty CTEPH patients (mean age, 58 ± 16 years; 19 men) with preoperative CTPA who underwent pulmonary endarterectomy (PEA) (08/2020-09/2021) were retrospectively included. Three radiologists scored each CTPA for chronic thromboembolism (occlusions, eccentric thickening, webs) using a 32-vessel model of the pulmonary vasculature, with interobserver agreement evaluated using Fleiss' kappa. CT level of disease was determined by the most proximal chronic thromboembolism: level 1 (main pulmonary artery), 2 (lobar), 3 (segmental) and 4 (subsegmental), and compared to surgical level at PEA.

Results

Interobserver agreement for CT level of disease was moderate overall (κ = 0.52). Agreement was substantial overall at the main/lobar level (κ, mean = 0.71) when excluding the left upper lobe (κ = 0.17). Though segmental and subsegmental agreement suffered (κ = 0.31), we found substantial agreement for occlusions (κ = 0.72) compared to eccentric thickening (κ = 0.45) and webs (κ = 0.14). Correlation between CT level and surgical level was strong overall (τb = 0.73) and in the right lung (τb = 0.68), but weak in the left lung (τb = 0.42) (p < 0.05). Radiologists often over- and underestimated the proximal extent of disease in right and left lung, respectively.

Conclusions

CT level of disease demonstrated good agreement between radiologists and was highly predictive of the surgical level in CTEPH. Occlusions were the most reliable sign of chronic thromboembolism and are important in assessing the segmental vasculature.

Insights From the FDA's MAUDE Database Regarding the Real-World Safety of Jetstream Atherectomy for Peripheral Arterial Disease

INTRODUCTION

Rotational atherectomy has shown promise as an adjunctive therapy to percutaneous transluminal angioplasty (PTA) and stenting for the treatment of peripheral arterial disease (PAD). However, published data regarding the safety of these devices are limited. The Food and Drug Administration Manufacturer and User Facility Device Experience (MAUDE) database collects reports of adverse event for medical devices. We present 3 years of MAUDE adverse events data for the Jetstream Atherectomy System (Boston Scientific) for the treatment of PAD.

MATERIALS AND METHODS

We searched MAUDE from January 1, 2019 to December 31, 2021. Duplicate reports and those with insufficient information were excluded, leaving a total of 500 reports for analysis. Adverse events were categorized as either patient complication, device malfunction, or both. Adverse events were classified using the Cardiovascular and Interventional Radiological Society of Europe's (CIRSE) classification system for adverse events.

RESULTS

The most common patient complications were embolism (22; 4.4%), dissection (17; 3.4%), vessel perforation (12; 2.4%), and device fracture in the patient (6; 1.2%). The most common modes of device failure were entrapment of the device on the guidewire (134; 27%), loss of blade rotation (116; 23%), loss of aspiration (99; 20%), and mechanical damage (57; 11%). As per the CIRSE adverse events classification, most events had no post-procedural sequelae (475; 95%), followed by those requiring prolonged observation (14; 2.8%), and post-procedural therapy without long-term sequelae (10; 2.0%). One hundred six devices (21%) were returned for manufacturer analysis.

CONCLUSION

We highlight important adverse events encountered in real-world practice with the Jetstream Atherectomy System. This analysis provides further understanding of the safety profile and modes of failure of Jetstream, and could help guide improvements in product design and manufacturer-user training. There is greater need for root-cause analysis that can aided by returning devices to the manufacturer.

CLINICAL IMPACT

We highlight important adverse events encountered in real-world practice with the Jetstream Atherectomy System. The MAUDE database is useful for capturing and characterizing modes of device failure/malfunction not typically described in conventional clinical studies. This may provide valuable information to help guide improvements in product design and manufacturer-user training. This information could also potentially be useful in helping establish manufacturer and product liability in the setting of medicolegal claims. We hope that by contributing to the growing understanding of the safety profile of the Jetstream Atherectomy System, our study may help physicians and patients come to more informed decisions regarding treatment options for PAD.

Chronic thromboembolic pulmonary hypertension secondary to a vascular malformation: case report diagnosis by lung subtraction iodine mapping

Chronic thromboembolic pulmonary hypertension (CTEPH) is a challenging diagnosis that can occur even in the absence of a prior thrombotic event. The main screening test is ventilation-perfusion (VQ) scintigraphy. The gold standard treatment for CTEPH is pulmonary endarterectomy (PEA), however, balloon pulmonary angioplasty (BPA) is an emerging treatment, especially for CTEPH at the segmental level. We report on a case of a patient with segmental CTEPH diagnosed by lung subtraction iodine mapping (LSIM) in the context of a chest wall vascular malformation. CTEPH was treated with BPA and by embolization and ligation of their vascular malformation.

Operator Intracranial Dose Protection During Fluoroscopic-Guided Interventions

PURPOSE

We utilized an anthropomorphic model made with a human skull to determine how different personal protective equipment influence operator intracranial radiation absorbed dose.

MATERIALS AND METHODS

A custom anthropomorphic phantom made with a human skull coated with polyurethane rubber, mimicking superficial tissues, and was mounted onto a plastic thorax. To simulate scatter, an acrylic plastic scatter phantom was placed onto the fluoroscopic table with a 1.5 mm lead apron on top. Two Radcal radiation detectors were utilized; one inside of the skull and a second outside. Fluoroscopic exposures were performed with and without radiation protective equipment in AP, 45-degree RAO, and 45-degree LAO projections.

RESULTS

The skull and soft tissues reduce intracranial radiation by 76% when compared to radiation outside the skull. LAO (308.95 μSv/min) and RAO projections (96.47μSv/min) result in significantly higher radiation exposure to the primary operator when compared to an AP projection (54 μSv/min). All tested radiation protection equipment demonstrated various reduction in intracranial radiation when compared to no protection. The hood (68% reduction in AP, 91% LAO, and 43% in RAO), full cover (53% reduction in AP, 76% in LAO, and 54% in RAO), and open top with ear coverage (43% reduction in AP, 77% reduction in LAO, and 22% in RAO) demonstrated the most reduction in intracranial radiation when compared to the control.

CONCLUSION

All tested equipment provided various degrees of additional intracranial protection. The skull and soft tissues attenuate a portion of intracranial radiation.

Vascular Closure Devices For Axillary Artery Access: A Systematic Review and Meta-Analysis

PURPOSE

To evaluate the technical success and complication rates of vascular closure devices (VCDs) in the axillary artery.

MATERIALS AND METHODS

MEDLINE and Embase were searched independently by two reviewers to identify observational studies from inception through October 2021. The following outcomes were meta-analyzed: technical success, hematoma, dissection, pseudoaneurysm, infection, and local neurological complications. Complications were also graded as mild, moderate, and severe. A logistic regression evaluating the influence of sheath size for the outcome of technical success rate was performed using individual patient-level data.

RESULTS

Of 1496 unique records, 20 observational studies were included, totaling 915 unique arterial access sites. Pooled estimates were as follows: technical success 84.8% (95% confidence interval [CI]: 78%-89.7%, I2=60.4%), hematoma 7.9% (95% CI: 5.8%-10.6%, I2=0%), dissection 3.1% (95% CI: 1.3%-7.3%, I2=0%), pseudoaneurysm 2.7% (95% CI: 1.3%-5.7%, I2=0%), infection <1% (95% CI: 0%-5.7%, I2=20.5%), and local neurological complications 2.7% (95% CI: 1.7%-4.4%, I2=0%). There was a significant negative association between sheath size and technical success rate (odds ratio [OR]: 0.87 per 1 French (Fr) increase in sheath size, 95% CI: 0.80-0.94, p=0.0005). Larger sheath sizes were associated with a greater number of access-site complications (adjusted odds ratio [aOR]: 1.21 per 1 Fr increase sheath size, 95% CI: 1.04-1.40, p=0.013).

CONCLUSIONS

Off-label use of VCDs in the axillary artery provides an 85% successful closure rate and variable complication rate, depending on the primary procedure and sheath size. Larger sheaths were associated with a lower technical success and greater rate of access-related complications.

CLINICAL IMPACT

Safe arterial access is the foundation for arterial intervention. While the common femoral artery is a well established access site, alternative arterial access sites capable of larger sheath sizes are needed in the modern endovascular era. This article provides the largest synthesis to date on the use of vascular closure devices for percutaneous axillary artery access in endovascular intervention. It should serve clinicians with added confidence around this approach in terms of providing a reference for technical success and complications. Clinically, this data is relevant for patient consent purposes as well as for practice quality improvement in setting safety standards for this access site.

Balloon Pulmonary Angioplasty for Chronic Thromboembolic Pulmonary Hypertension: A Systematic Review and Meta-analysis

PURPOSE

To perform a systematic review and meta-analysis assessing the safety and efficacy of balloon pulmonary angioplasty (BPA) in the treatment of chronic thromboembolic pulmonary hypertension (CTEPH).

MATERIALS AND METHODS

Systematic literature searches were performed from inception to June 2022 to identify studies assessing BPA for CTEPH. Outcomes of interest included the following functional and hemodynamic measures: (a) six-minute walk distance (6MWD), (b) New York Heart Association (NYHA) status, (c) World Health Organization (WHO)-Functional Class status, (d) cardiac index (CI), (e) mean pulmonary artery pressure (mPAP), (f) mean right atrial pressure (mRAP), and (g) pulmonary vascular resistance (PVR). Subgroup analysis was also performed for BPA in post-pulmonary endarterectomy (PEA) patients. All reported BPA-related complications were also recorded. Forty unique studies with a total of 1763 patients were identified for meta-analysis.

RESULTS

All functional and hemodynamic parameters improved significantly following BPA; 6MWD increased 70 m (95% CI 58-82; P < 0.001), NYHA class improved by - 0.9 classes (95% CI - 1.0 to - 0.8; P < 0.001), WHO-FC class improved by - 1 classes ((95% CI - 1.2 to - 0.9; P < 0.001), CI increased 0.26 L/min/m² (95% CI 0.17-0.35; P < 0.001), mPAP decreased - 13.2 mmHg (95% CI - 14.7 to - 11.8; P < 0.001), mRAP decreased - 2.2 mmHg (95% CI - 2.8 to - 1.6; P < 0.001), and PVR decreased - 311 dyne/cm/s^-5 (95% CI - 350 to - 271; P < 0.001). Meta-analysis of patients who underwent BPA for persistent pulmonary hypertension post-PEA demonstrated significant improvements in 6MWD, WHO-FC, PVR and mPAP. Most common complications included lung injury (8.16%), hemoptysis (7.07%) and vessel injury (5.05%).

CONCLUSION

BPA represents a safe and effective treatment option for select individuals with CTEPH with significant improvements in hemodynamic parameters, improved exercise tolerance and a relatively low risk of major complications.

The Use of Vascular Closure Devices for Brachial Artery Access: A Systematic Review and Meta-Analysis

PURPOSE

To estimate the rates of technical success and adverse events of vascular closure devices (VCDs) in the brachial artery and compare the rates of adverse events with manual compression.

MATERIALS AND METHODS

MEDLINE and Embase were searched for observational studies examining VCDs in the brachial artery. Meta-analyses were performed using random effects for the following outcomes: (a) technical success, (b) hematoma at the access site, (c) pseudoaneurysm, (d) local neurological adverse events, and (e) total number of adverse events. A pairwise meta-analysis compared VCD with manual compression for the outcomes of hematoma and the total number of adverse events.

RESULTS

Of 1,761 eligible records, 16 studies including 510 access sites were included. Primary procedures performed were peripheral arterial disease interventions, percutaneous coronary intervention, and endovascular thrombectomy for ischemic stroke. The technical success rate was 93% (95% CI, 87%-96%; I² = 47%). Data on the following adverse events were obtained via meta-analysis: (a) hematoma, 9% (5%-15%; I² = 54%); (b) stenosis or occlusion at access site, 3% (1%-14%; I² = 51%); (c) infection, 0% (0%-5%; I² = 0%); (d) pseudoaneurysm, 4% (1%-13%; I² = 61%); (e) local neurological adverse events, 5% (2%-13%; I² = 54%); and (f) total number of adverse events, 15% (10%-22%; I² = 51%). Angio-Seal success rate was 96% (93%-98%; I² = 0%), whereas the ExoSeal success rate was 93% (69%-99%; I² = 61%). When comparing VCD and manual compression, there was no difference in hematoma formation (relative risk, 0.75; 95% CI, 0.35-1.63; I² = 0%; P = .47) or the total number of adverse events (relative risk, 0.75; 95% CI, 0.35-1.58; I² = 76%; P = .45).

CONCLUSIONS

Despite being off-label, studies suggest that VCDs in the brachial artery have a high technical success rate. There was no significant difference in adverse events between VCDs and manual compression in the brachial artery.

Minimally Invasive Segmental Artery Coil Embolization (MISACE) Prior to Endovascular Thoracoabdominal Aortic Aneurysm Repair

PURPOSE

Minimally Invasive Segmental Artery Coil Embolization (MISACE) is a novel approach to reduce paraplegia risk in Thoracoabdominal aortic aneurysm (TAAA) repair with limited data. We report our experience with MISACE as a method of spinal cord pre-conditioning to prevent spinal cord ischemia following endovascular repair of TAAA.

MATERIAL AND METHODS

A retrospective analysis of 17 patients who had an attempted MISACE prior to endovascular TAAA repair with mean follow-up of 350 days (2017-2020). Baseline patient and aneurysm characteristics along with procedural technique and outcomes were analyzed.

RESULTS

Mean age of 69 years and 76.5% were males. TAAA Crawford classification were II, n = 6 (35.3%), III, n = 4 (23.5%) and IV, n = 5 (29.4%). The mean aortic diameter was 70.6 ± 10.9 mm. Staged repair was performed on 9 patients. Technically successful embolization occurred in 14 patients (82.4%) and was unsuccessful in 3 patients. The median number of embolized arteries was 3 and 71% of the target arteries were between T9 and T12. Mean fluoroscopy time was 51.5 ± 22.5 min and mean contrast volume used was 132.8 ± 56.1 mL. Average number of catheters used was 4.6 and 3.5 wires. No complications related to the procedure. Mean interval between embolization to endovascular TAAA repair was 51.2 days (5-110 days). All patients received spinal drainage at the time of repair. Postoperatively, 2/14 of patients developed paraparesis in the MISACE successful group and 1/3 patients developed paraplegia in the unsuccessful group.

CONCLUSIONS

MISACE is a promising strategy to prevent SCI. This data demonstrates the technique is feasible and safe but anatomic challenges remain.

Percutaneous Transluminal Angioplasty for Below-the-Elbow Critical Hand Ischemia: A Systematic Review

PURPOSE

To perform a systematic review assessing the safety and efficacy of percutaneous transluminal angioplasty (PTA) for treatment of critical hand ischemia (CHI) due to below-the-elbow (BTE) obstructive arterial disease.

MATERIALS AND METHODS

MEDLINE and EMBASE systematic searches were performed from inception to December 2020 to identify studies assessing PTA for management of BTE obstructive arterial disease. Three independent reviewers performed abstract selection, data extraction, and quality assessment. The Newcastle-Ottawa Scale was used to assess individual study bias for non-randomized controlled trials.

RESULTS

Eight studies comprising 176 patients with obstructive BTE vessel disease were included. All studies had a score >5 on the Newcastle-Ottawa Scale, indicative of high quality. All studies used low-profile balloons (1.5-4 mm) for PTA of stenotic lesions or chronic total occlusions (CTOs). The weighted average technical success and clinical success rates were 89.3% (range = 82%-100%) and 69.9% (range = 19%-100%), respectively, at a mean follow-up of 29.7 ± 17.1 months. The short-term (<30 days) complication rate was low at 4.7% and most commonly included access site hematomas, pseudoaneurysms, and radial artery perforation or re-thrombosis. Nearly 20% of patients required an amputation, and most (96%) were minor (either distal phalanges or digits). Only 2 patients required above-wrist amputations. The primary and secondary patency rate at 5 years were 38% and 54%, respectively. The cumulative 5-year mortality rate was 33.1%.

CONCLUSIONS

PTA for CHI due to BTE obstructive arterial disease is feasible with a high technical success rate and a low short-term complication rate. Additional long-term comparative studies are required to unequivocally establish the clinical benefit of endovascular treatment compared with conservative management or surgical bypass.

Abstract 347: Using Deep Convolutional Neural Networks To Automate Classification Of Carotid Plaques From Ultrasound Imaging

Background: Stroke is a devastating consequence of plaque rupture from the carotid arteries. Current management of carotid plaques involves waiting for symptoms (e.g., stroke or mini-stroke), as intervention itself has risk of stroke and not all plaques are vulnerable to rupture. There is a need to better risk-stratify plaque that causes stroke. Carotid ultrasound (US) is a non-invasive and inexpensive visualization of plaques but is limited by human interpretation. We hypothesize that convolutional neural networks (CNNs) will identify unique features of carotid plaques for automated risk stratification.

Methods: Our workflow is illustrated in Fig. a. A total of 141 B-mode US images of carotid arteries were included; 64 high-risk with symptomatic carotid plaques and 75 low-risk with no significant plaque. Data was cropped and divided into training (70%) and holdout test (30%) subsets. During model training, an ensemble of ResNet-18 CNNs learned classification of low-risk and high-risk cases using five-fold stratified cross validation and was used to predict on the holdout test set. The model was evaluated using ROC-AUC and sensitivity. Saliency maps were used for model interpretability to highlight relevant pixels for model decisions.

Results: The cross-validation AUC was 0.995 ± 0.010. The testing AUC was 0.909 and class-wise sensitivities were 0.88 (low-risk) and 0.79 (high-risk). The density plot (Fig. b) shows that the classifier correctly identifies both classes with confidence. Model interpretability using saliency maps (Fig. c) shows pixels corresponding to carotid artery vessel edges and in high-risk cases, carotid plaques.

Conclusions: Using this proof-of-concept model, carotid US long axis images are sufficient to identify high-risk plaques in symptomatic patients - we now need to determine whether we can identify high-risk plaques before symptoms to prevent devastating stroke caused by carotid disease.

Integrated Pulmonary Index during nurse-administered procedural sedation: Study protocol for a cluster-randomized trial

AIM

To determine if smart alarm-guided treatment of respiratory depression using the Integrated Pulmonary Index is an effective way to implement capnography during nurse-administered sedation.

DESIGN

Parallel cluster-randomized trial.

METHODS

Nurses will be randomized to use capnography with or without the Integrated Pulmonary Index enabled. Capnography alarm performance will be compared between nurses using capnography alone or with the Integrated Pulmonary Index enabled. The target sample size is 400 adult patients scheduled for elective procedures with nurse-administered sedation. The primary outcome is the number of seconds in an alert condition state without an intervention being applied. Secondary outcomes are alarm burden, number of appropriate alarms, number of inappropriate alarms, total duration of alert conditions, choice of alarm settings and adverse sedation events. This study has been funded since April 2021.

DISCUSSION

Implementing capnography into practice for respiratory monitoring during nurse-administered sedation is considered a high priority. The Integrated Pulmonary Index shows promise as a strategy to optimize the implementation of capnography for respiratory monitoring during nurse-administered sedation. If it is found in this study that using the Integrated Pulmonary Index improves the nursing management of physiologically abnormal states during nurse-administered sedation, it would provide the high-level evidence needed to support broader use of this 'smart alarm' strategy for respiratory monitoring in practice.

IMPACT

With advances in medical technology continuing to expand the indications for minimally invasive surgical techniques, the use of nurse-administered sedation during medical procedures is likely to expand in the future. The findings may be applied to other populations receiving nurse-administered sedation during medical procedures. Results from this study will help translate the usage of smart alarm-guided treatment of respiratory depression during procedural sedation.

TRIAL REGISTRATION

NCT05068700.

Minimally invasive delivery of ethanol for the treatment of urinary bladder fistulas

Urinary bladder fistula formation is a complication of significant morbidity and mortality following pelvic surgery or radiotherapy. Surgical treatment is the definitive management, but it may be contraindicated in patients with significant comorbidities. The alternative approach is to divert urine away from the fistula with stents and catheters, and allow time for healing. The case illustrated herein describes the use of alcohol to accelerate the fibrotic healing of a urinary bladder fistula, based on the premise that sclerosing agents have been effective in the treatment of pancreatic fistulas and renal cysts.

Percutaneous Drainage for Aortic Graft Infection Post-aneurysm Repair: A Viable Option?

Purpose

Non-operative management of aortic graft infection is usually only considered in a palliative context. We describe the safety, efficacy, and clinical outcomes of percutaneous drainage of aortic graft infections (AGI) following either open or endovascular repair of aneurysmal disease.

Methods

Twelve consecutive patients (11 males, 1 female, mean age 72.7 ± 10.3 years, age range 52-88 years) between January 2010-July 2020 who underwent percutaneous drain insertion in either an infected aortic sac or periaortic abscess cavity following endovascular or open surgical graft repair were identified. Patient and procedural characteristics as well as clinical outcomes were determined.

Results

Of the 12 patients who underwent percutaneous drain insertion, five (41.7%) had undergone open abdominal aneurysm repair, one (8.3%) open thoracoabdominal aneurysmal repair, and six (50%) endovascular abdominal aneurysm repairs. Drain size ranged from 10-20 French. All were inserted under ultrasound (US), computed tomography (CT), and/or fluoroscopic guidance. Median duration of drain placement was 55.2 days (range 3-174). Five patients (41.7%) had the drain in place as a stabilizing bridge until or after definitive surgical explantation and aortic reconstruction. Seven patients (58.3%) were managed with drain placement and antibiotic therapy without surgical intervention. Six (50%) were alive at the most recent time of follow-up (median, 732 days, range 166-1650 days). Three patients (25%) died during follow-up with causes including erosion of aortic reconstruction into sigmoid colon, unrelated chronic obstructive pulmonary disease exacerbation, and severe clostridium difficile colitis and pseudomonal pneumonia (median 1244 days, range 992-1597 days). Three (25%) patients were lost to follow-up. No drain-related complications were noted.

Conclusion

Percutaneous drainage of AGI following endovascular or open aneurysm repair is a safe and viable management option either as a temporizing measure as a bridge to surgical graft explantation or as a non-surgical therapy for long term management.

SUPERA Stenting in the Common Femoral Artery: Early Experience and Practical Considerations

Purpose

Endovascular therapy in the management of de novo common femoral disease remains controversial. Considerable interest has been generated in recent years due to recent technological advancement in the design of vascular stents. In particular, SUPERA (Abbot Vascular Inc, Santa Clara USA) stents are designed to offer increased flexibility and less adverse interactions with the arterial wall, thus making it potentially better suited for common femoral lesions. However, despite such theoretical advantages, there is lack of data in its use in clinical practice. This study provides illustrative examples of SUPERA stents in different clinical settings and contributes to important clinical data for the overall efficacy and safety profile of endovascular interventions in common femoral artery (CFA) disease.

Materials and Methods

Retrospective analysis of all endovascular CFA procedures between January 1, 2011, and December 31, 2019, was conducted. Data collected included demographics, clinical symptoms, medical comorbidities, procedural characteristics, and immediate and short-term complications. Detailed analysis was performed on the stenting cohort.

Results

During our study period, a total of 69 patients underwent endovascular interventions involving the CFA at our institution, of which 16 patients had stenting procedures for a total of 18 stent deployments. Technical success was achieved in all stenting procedures. A total of 15 SUPERA stents were placed in 13 patients. No stent fractures were observed. Overall primary patency rate of SUPERA stents at the time of 12-month follow-up was 100% in patients who had a follow-up assessment (n = 12 stents).

Conclusion

Endovascular intervention of the CFA is an evolving topic in the interventional radiology and vascular surgery community. Recent development of newer generation of devices such as SUPERA peripheral stents offers significant potential benefits given their inherent design. Despite the theoretically promising design of the SUPERA, there is a lack of data to support its use. This study contributes important patient-level data for SUPERA stent deployments.

Endovascular coil embolization of inferior mesenteric artery to ileal-conduit fistula: a case report

BACKGROUND

Uretero-arterial fistulas (UAFs) are uncommon and pose a diagnostic dilemma, making them life threatening if not recognized and treated expediently. UAFs to small arteries such as a branch of the inferior mesenteric artery (IMA) are very uncommon and present a further diagnostic and treatment challenge. There should be a high index of suspicion for UAFs when intervening on patients with history of treated pelvic cancers and long-standing ureteric stents experiencing hematuria not attributable to another cause.

CASE PRESENTATION

We present a case of a fistula formed between a distal branch of the IMA-superior rectal artery-and an ileal-conduit in a patient with a long-standing reverse nephroureterostomy (Hobbs) catheter presenting with abdominal pain and hematuria through the conduit. During a tube exchange, contrast injection demonstrated a fistula with the superior rectal artery, multiple ileal intraluminal blood clots, and active extravasation. The patient became tachycardic and hypotensive, actively bleeding through the ileal-conduit, prompting a massive transfusion protocol. Successful endovascular coiling of the superior rectal artery was performed with resolution of active extravasation and stabilization of the patient. The patient recovered and was discharged in stable condition 10 days later.

CONCLUSIONS

Although UAFs are uncommon, our case demonstrated key predisposing risk factors to fistula development; pelvic cancer surgery, pelvic radiation, and a prolonged ureteric stent through the ileal-conduit. Typically, UAFs arise from communication with the iliac arterial system, however in this instance we have demonstrated that fistulization to other arterial vessels is also possible. Endovascular management has become the preferred method of therapy, typically involving the placement of covered stents when involving the iliac arterial system. In this instance stent grafting was not possible due to the small caliber vessel and therefore had to be embolized.

Assessment of open surgical and endovascular management of true hepatic artery aneurysms over 20 years highlights increased rupture risk in females

BACKGROUND

True hepatic artery aneurysms (HAAs) are rare but have been associated with a significant risk of rupture and associated mortality. The 2020 release of HAA-specific clinical practice guidelines represented an important step toward management standardization. However, it remains essential to build on the body of evidence to further refine these recommendations.

METHODS

The HAA management and outcomes from a single academic center during a 20-year period were retrospectively reviewed. We identified 72 patients from the institutional radiology database (November 24, 1999 to 2019). Pseudoaneurysms were excluded, and 48 patients were found to have had true HAAs. Forty-three HAA patients had sufficient medical records for inclusion in the analysis.

RESULTS

Of the 43 patients with HAA included, 65% were male. The mean age was 63 years (range, 22-89 years). Of the HAAs, 72% presented asymptomatically, 16% had ruptured, and 12% were symptomatic at presentation. Most HAAs were of atherosclerotic origin (74%). In addition, 16% of the patients had other visceral aneurysms and 12% had nonvisceral aneurysms on presentation. The mean HAA size overall was 3.3 cm (range, 0.8-10.8 cm), with most being solitary (72%) and involving the common hepatic artery (65%). Rupture was more common in females (40%) and those with vasculitis (67%), with females representing 86% of all patients with rupture. The mean size at intervention was 4.8 cm (21 patients [49%]). Ten patients (23%) had undergone open surgical repair (seven elective and three emergent because of rupture). Eleven patients (26%) had undergone endovascular intervention (64% elective and 36% emergent). Nonoperative management was selected for 22 patients (51%). These patients had a mean HAA diameter of 2.1 cm, and 59% had a life-limiting illness. Of the 18 patients who had been initially monitored for a mean of 3.9 ± 4.1 years, 3 had undergone elective repair and 2 had minimal growth. None of these patients had a subsequently documented rupture.

CONCLUSIONS

True HAAs are a rare but important clinical phenomenon, with 16% of patients presenting with rupture in this study. Endovascular intervention is a promising alternative to open surgical repair, with no 30-day mortality, and is suitable for ruptured HAAs. Importantly, for the first time, our findings have demonstrated an increased risk of rupture for females, highlighting the need for additional data and ultimately, sex-specific guidelines.

Effect of vertebral compression fractures on aortic neck angulation after endovascular aneurysm repair

OBJECTIVE

Aortic neck angulation (ANA) prior to endovascular aneurysm repair (EVAR) and its changes after EVAR are considered important predictors of postoperative complications. We sought to assess the effects of vertebral body height loss on ANA in patients post-EVAR.

METHODS

All patients who had undergone EVAR for infrarenal aortic aneurysms in our institution between August 2010 and December 2018 were assessed. Anterior and posterior vertebral body heights were measured in all patients on preoperative, early postoperative, and follow-up computed tomography scans (T12-L5 vertebral bodies). Patients who had significant height loss in their follow-up period were designated as the Study group. These were matched to a Control group of the same size using propensity-score matching based on age, gender, and duration between follow-up scans. Aortic neck morphology indices including ANA and its changes were measured, and information related to postoperative endoleaks and aneurysm sac size were extracted in the Study and Control groups.

RESULTS

During the follow-up period, 10 of 185 patients had a radiologically significant vertebral body compression fracture. There was no significant difference between the Study (n = 10) and Control groups in age (77.6 ± 6.9 vs 77.2 ± 7.5 years; P = .64), gender (seven males and three females in each group; P = 1.0), duration between postoperative scans (1830 ± 665 vs 1800 ± 670 days; P = .25), preoperative ANA (36.0° ± 15.6° vs 42.4° ± 18.6°; P = .41), and early postoperative ANA (21.9° ± 11.7° vs 20.9° ± 16.3°; P = .72). Changes in ANA in the postoperative period (7.2° ± 11.1° vs -4.7° ± 6.7°; P = .009; power = .838) were significantly higher in the Study group.

CONCLUSION

Post-EVAR vertebral body compression fractures exacerbate ANA. Awareness of this can guide both preoperative assessment and postoperative management and follow-up.

Predicting Prolonged Apnea During Nurse-Administered Procedural Sedation: Machine Learning Study

BACKGROUND

Capnography is commonly used for nurse-administered procedural sedation. Distinguishing between capnography waveform abnormalities that signal the need for clinical intervention for an event and those that do not indicate the need for intervention is essential for the successful implementation of this technology into practice. It is possible that capnography alarm management may be improved by using machine learning to create a "smart alarm" that can alert clinicians to apneic events that are predicted to be prolonged.

OBJECTIVE

To determine the accuracy of machine learning models for predicting at the 15-second time point if apnea will be prolonged (ie, apnea that persists for >30 seconds).

METHODS

A secondary analysis of an observational study was conducted. We selected several candidate models to evaluate, including a random forest model, generalized linear model (logistic regression), least absolute shrinkage and selection operator regression, ridge regression, and the XGBoost model. Out-of-sample accuracy of the models was calculated using 10-fold cross-validation. The net benefit decision analytic measure was used to assist with deciding whether using the models in practice would lead to better outcomes on average than using the current default capnography alarm management strategies. The default strategies are the aggressive approach, in which an alarm is triggered after brief periods of apnea (typically 15 seconds) and the conservative approach, in which an alarm is triggered for only prolonged periods of apnea (typically >30 seconds).

RESULTS

A total of 384 apneic events longer than 15 seconds were observed in 61 of the 102 patients (59.8%) who participated in the observational study. Nearly half of the apneic events (180/384, 46.9%) were prolonged. The random forest model performed the best in terms of discrimination (area under the receiver operating characteristic curve 0.66) and calibration. The net benefit associated with the random forest model exceeded that associated with the aggressive strategy but was lower than that associated with the conservative strategy.

CONCLUSIONS

Decision curve analysis indicated that using a random forest model would lead to a better outcome for capnography alarm management than using an aggressive strategy in which alarms are triggered after 15 seconds of apnea. The model would not be superior to the conservative strategy in which alarms are only triggered after 30 seconds.

Global trends in chronic thromboembolic pulmonary hypertension clinical trials and dissemination of results

Treatment options for chronic thromboembolic pulmonary hypertension (CTEPH) are rapidly expanding. The purpose of this study is to identify trends in CTEPH clinical trials and the publication of results. We performed a worldwide review of completed and ongoing clinical trials through searching the ClinicalTrials.gov database and the World Health Organization International Clinical Trials Registry Platform for "CTEPH" and related terms. Entries were classified as pharmaceutical/procedural interventions (Group 1), all other clinical trials (Group 2) and patient registries (Group 3). Trial characteristics and national affiliation were recorded. PubMed was searched for related publications. There were 117 clinical trials registry entries after removing duplicates and non-target records. Group 1 comprised 29 pharmaceutical, 15 procedural, and four combined interventions starting in 2005, 2010, and 2016, respectively. Riociguat and balloon pulmonary angioplasty were the most frequent pharmaceutical and procedural interventions, respectively. The proportion of procedural trials increased over time from 0% of those in 2005-2009 to 29% in 2010-2014 and 54% in 2015-2020. There were 56 entries in Group 2 and 13 in Group 3. Japan was the most frequent national affiliation and the most frequent participating country, present in 28% of all trials. The proportion of entries with published results was highest with Group 3 (62%) and lowest with Group 1 (27%). Thirty percent of all publications occurred in 2020. In conclusion, CTEPH clinical trials are increasingly procedural based, with growth largely attributable to Japan and balloon pulmonary angioplasty. Most trials have not published, but results from balloon pulmonary angioplasty clinical trials are anticipated soon.

Evaluation and management of patients with chronic thromboembolic pulmonary hypertension - consensus statement from the ISHLT

ISHLT members have recognized the importance of a consensus statement on the evaluation and management of patients with chronic thromboembolic pulmonary hypertension. The creation of this document required multiple steps, including the engagement of the ISHLT councils, approval by the Standards and Guidelines Committee, identification and selection of experts in the field, and the development of 6 working groups. Each working group provided a separate section based on an extensive literature search. These sections were then coalesced into a single document that was circulated to all members of the working groups. Key points were summarized at the end of each section. Due to the limited number of comparative trials in this field, the document was written as a literature review with expert opinion rather than based on level of evidence.

Overall Impact of the COVID-19 Pandemic on Interventional Radiology Services: A Canadian Perspective

PURPOSE

The aim of this national survey was to assess the overall impact of the coronavirus disease 2019 (COVID-19) pandemic on the provision of interventional radiology (IR) services in Canada.

METHODS

An anonymous electronic survey was distributed via national and regional radiology societies, exploring (1) center information and staffing, (2) acute and on-call IR services, (3) elective IR services, (4) IR clinics, (5) multidisciplinary rounds, (6) IR training, (7) personal protection equipment (PPE), and departmental logistics.

RESULTS

Individual responses were received from 142 interventional radiologists across Canada (estimated 70% response rate). Nearly half of the participants (49.3%) reported an overall decrease in demand for acute IR services; on-call services were maintained at centers that routinely provide these services (99%). The majority of respondents (73.2%) were performing inpatient IR procedures at the bedside where possible. Most participants (88%) reported an overall decrease in elective IR services. Interventional radiology clinics and multidisciplinary rounds were predominately transitioned to virtual platforms. The vast majority of participants (93.7%) reported their center had disseminated an IR specific PPE policy; 73% reported a decrease in case volume for trainees by at least 25% and a proportion of trainees will either have a delay in starting their careers as IR attendings (24%) or fellowship training (35%).

CONCLUSION

The COVID-19 pandemic has had a profound impact on IR services in Canada, particularly for elective cases. Many centers have utilized virtual platforms to provide multidisciplinary meetings, IR clinics, and training. Guidelines should be followed to ensure patient and staff safety while resuming IR services.

Endovascular community response to mortality data in use of paclitaxel devices for peripheral vascular disease

OBJECTIVES

Examine the endovascular community response to data demonstrating increased mortality in paclitaxel devices for the treatment of peripheral arterial disease in femoropopliteal lesions.

METHODS

A retrospective observational study using the Vascular Quality Initiative Peripheral Vascular Intervention registry dataset was performed examining paclitaxel device use for peripheral arterial disease in femoropopliteal arteries treated from 2017-2019. A total of 41707 patients and 52208 procedures were analyzed during the study period. Post-hoc analysis was performed to examine use during selected time periods in 2019.

RESULTS

Total femoropopliteal procedures in 2017, 2018, and 2019 were 17458, 21140, and 21322, respectively. Paclitaxel devices were used for 8852 arteries in 2017, 10691 in 2018, and 6732 in 2019, which was significantly reduced, when comparing 2019 volumes to 2017 or 2018 (p < .0001) and 2019 versus 2018 + 2017 volumes (p < .0001). Post-hoc analysis of selected times in 2019 demonstrated variable use throughout 2019.

CONCLUSIONS

Following publication of data with concerns of mortality associated with paclitaxel device use in 2018, a rapid reduction in overall paclitaxel device use was observed in 2019.

Arteries of the Lower Limb-Embryology, Variations, and Clinical Significance

OBJECTIVES

The purpose of this article is to review the embryology of the lower limb arterial anatomy along with common variants and their clinical relevance.

DESIGN

Embryologic variations of the lower limb arterial system may be explained by i.) persistence of primordial arterial segments, ii.) abnormal fusion, iii.) segmental hypoplasia/absence, or a combination of both. Persistent sciatic artery, corona mortis, and popliteal entrapment syndrome will also be discussed with associated symptoms, and potential complications.

CONCLUSION

Knowledge of these variations is essential for surgical and endovascular management as failure to recognize them can result in complications.

Randomized Controlled Trial of Percutaneous Radiologic Gastrostomy Performed With and Without Gastropexy: Technical Success, Patient-Reported Outcomes and Safety

PURPOSE

The aim of this study is to compare balloon-retention percutaneous radiologic gastrostomy (PRG) tube insertion performed with and without gastropexy, primarily focusing on pain and patient-reported outcomes.

MATERIALS AND METHODS

Research ethics board approved a dual-arm, single-centre, randomized trial of 60 patients undergoing primary 14-French PRG tube insertion (NCT04107974). Patients were randomized to receive either PRG with gastropexy or without gastropexy. Data were collected for technical outcomes, patient-reported outcomes pre-procedure, post-procedure and at 1-month, as well as quality of life parameters at 1-month post-procedure (EQ5D-5L, Visual Analogue Scale and Functional Assessment of Cancer Therapy-Enteral Feeding questionnaires). Complications occurring up to 6-months post-procedure were recorded.

RESULTS

Sixty patients were randomized to the gastropexy group (n = 30) or non-gastropexy (n = 30) group. One non-gastropexy patient was withdrawn from the study due to failed insertion. PRG procedural time was significantly longer when using gastropexy (mean 11.4 ± 7.19 min) compared with non-gastropexy (mean 6.79 ± 4.63 min; p < 0.05). Pain scores did not differ between the two groups pre-procedure, post-procedure and at 1-month follow-up, nor did 1-month quality of life parameters. Six (20%) minor complications occurred in the gastropexy group and nine (31%) minor complications in the non-gastropexy group (p = 0.330). Two (6.9%) major complications occurred in the non-gastropexy group (p = 0.458).

CONCLUSION

There is comparable patient tolerability when balloon-retention PRG insertion is performed with or without gastropexy sutures. This study also demonstrated a trend towards fewer complications when gastropexy is utilized. However, further larger trials are required to compare complications of the two approaches for PRG insertion.

LEVEL OF EVIDENCE

Level 2, randomized trial.

Midazolam for sedation before procedures in adults and children: a systematic review update

BACKGROUND

Midazolam is used for sedation before diagnostic and therapeutic medical procedures by several routes including oral, intravenous, intranasal and intramuscular. This is an update of a Cochrane review published in 2016, which aimed to determine the evidence on the effectiveness of midazolam for sedation when administered before a diagnostic or therapeutic procedure in adults and children.

METHODS

We searched CENTRAL, MEDLINE, Embase and two trials registers up to May 2020 together with reference checking to identify additional studies. We imposed no language restrictions. Randomized controlled trials of midazolam in comparison with placebo or other medications used for sedation were included. Two authors independently extracted data and assessed risk of bias for each included study.

RESULTS

Eight new trials were included in this update, which resulted in changed conclusions for the intravenous midazolam versus placebo, oral midazolam versus chloral hydrate and oral midazolam versus placebo comparisons. Effect estimates for all outcomes within the intravenous midazolam versus placebo (7 trials; 633 adults and 32 children) are uncertain due to concerns about imprecision and risk of bias. Midazolam resulted in a higher level of sedation than placebo (mean difference (MD) 1.05; 95% confidence interval (95% CI) 0.69 to 1.41; 1 study; 100 adults). There was no difference in anxiety (RR 0.43, 95% CI 0.09 to 1.99; I² = 75%; 2 studies; 123 adults). Risk of difficulty performing procedures was lower in the midazolam group (RR 0.5; 95% CI 0.29 to 0.86; I² = 45%; 3 studies; 191 adults and 32 children). There was no difference in discomfort (RR 0.51; 95% CI 0.25 to 1.04; I² = 0%; 2 studies; 190 adults). Five trials with 336 children were included in the oral midazolam versus chloral hydrate comparison. Midazolam was less likely to result in moderate sedation (RR 0.30, 95% CI 0.11 to 0.82; I² = 64%; 2 studies, 228 participants). This effect estimate is highly uncertain due to concerns about the risk of bias, imprecision and inconsistency. There was no difference in ratings of anxiety (SMD - 0.26; 95% CI - 0.75 to 0.23; I² = 0%; 2 studies; 68 participants). Midazolam increased risk of incomplete procedures (RR 4.01; 95% CI 1.92 to 8.40; I² = 0%; 4 studies, 268 participants). This effect estimate is uncertain due to concerns about the risk of bias. There were four trials with 359 adults and 77 children included in the oral midazolam versus placebo comparison. Midazolam reduced ratings of anxiety (SMD - 1.01; 95% CI - 1.86 to - 0.16; I² = 92%; 4 studies; 436 participants). It is unclear if midazolam has an effect on difficulty performing procedures. Meta-analysis was not performed because there was only one incomplete procedure in the midazolam group in one of the trials. Midazolam reduced pain in one study with 99 adults (MD - 2; 95% CI - 2.5 to - 1.6; moderate quality). The effect estimate is uncertain due to concerns about the risk of bias.

CONCLUSION

The additional evidence arising from inclusion of new studies in this updated review has not produced sufficient high-quality evidence to determine whether midazolam produces more effective sedation than other medications or placebo in any specific population included in this review. For adults, there was low-quality evidence that intravenous midazolam did not reduce the risk of anxiety or discomfort/pain in comparison to placebo, but the sedation level was higher. By combining results from adults and children, there was low-quality evidence of a large reduction in the risk of procedures being difficult to perform with midazolam in comparison to placebo. The effect estimates for this comparison are uncertain because there was concern about risk of bias and imprecision. There is moderate-quality evidence suggesting that oral midazolam produces less-effective sedation than chloral hydrate for completion of procedures for children undergoing non-invasive diagnostic procedures. Ratings of anxiety were not different between oral midazolam and chloral hydrate. The extent to which giving oral midazolam to adults or children decreases anxiety during procedures compared with placebo is uncertain due to concerns about risk of bias and imprecision. There was moderate-quality evidence from one study that oral midazolam reduced the severity of discomfort/pain for adults during a brief diagnostic procedure in comparison with placebo.

CT perfusion in peripheral arterial disease-hemodynamic differences before and after revascularisation

Objectives

The purpose of this study was the assessment of volumetric CT perfusion (CTP) of the lower leg musculature in patients with symptomatic peripheral arterial disease (PAD) before and after interventional revascularisation.

Methods

Twenty-nine consecutive patients with symptomatic PAD of the lower extremities requiring interventional revascularisation were assessed prospectively. All patients underwent a CTP scan of the lower leg, and hemodynamic and angiographic assessment, before and after intervention. Ankle-brachial pressure index (ABI) was determined. CTP parameters were calculated with a perfusion software, acting on a no outflow assumption. A sequential two-compartment model was used. Differences in CTP parameters were assessed with non-parametric tests.

Results

The cohort consisted of 24 subjects with an occlusion, and five with a high-grade stenosis. The mean blood flow before/after (BFpre and BFpost, respectively) was 7.42 ± 2.66 and 10.95 ± 6.64 ml/100 ml*min⁻¹. The mean blood volume before/after (BVpre and BVpost, respectively) was 0.71 ± 0.35 and 1.25 ± 1.07 ml/100 ml. BFpost and BVpost were significantly higher than BFpre and BVpre in the treated limb (p = 0.003 and 0.02, respectively), but not in the untreated limb (p = 0.641 and 0.719, respectively).

Conclusions

CTP seems feasible for assessing hemodynamic differences in calf muscles before and after revascularisation in patients with symptomatic PAD. We could show that CTP parameters BF and BV are significantly increased after revascularisation of the symptomatic limb. In the future, this quantitative method might serve as a non-invasive method for surveillance and therapy control of patients with peripheral arterial disease.

Key Points

• CTP imaging of the lower limb in patients with symptomatic PAD seems feasible for assessing hemodynamic differences before and after revascularisation in PAD patients.

• This quantitative method might serve as a non-invasive method, for surveillance and therapy control of patients with PAD.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00330-021-07692-5.