Infrapopliteal Calcium Score for PAD

Clinical Utility of Infrapopliteal Calcium Score for the Evaluation of Severity of Peripheral Artery Disease

Clinical question

To identify associations between computed tomography (CT)–based lower-extremity calcium score (LECS) across different anatomic segments and the presence, severity, and clinical outcomes of peripheral artery disease (PAD).

Take away point

An infrapopliteal calcium score of >188 Agatston units was associated with increased odds of having CLTI and was a potent predictor of CLTI and all-cause mortality among claudicants who were prospectively followed.

Reference

Lee, Sujin, Mari Tanaka, Shiv Patel, Nikolaos Zacharias, Sandeep Hedgire, Rajeev Malhotra, and Anahita Dua. "Clinical Utility of Infrapopliteal Calcium Score for the Evaluation of Severity of Peripheral Artery Disease." Journal of Vascular and Interventional Radiology 35, no. 3 (2024): 370-376.

Click here for abstract

Study design

Retrospective multi-institutional database with a prospective component for model validation

Funding Source

None reported

Setting

Academic

Figure

Kaplan–Meier and Cox proportional hazards analysis of chronic limb-threatening ischemia (CLTI) and death among claudicants. Patients with an infrapopliteal calcium score of ≥188 had a significantly higher risk of progressing to CLTI or death compared with those with a calcium score of <188 (log-rank P = .0036). On the univariate Cox proportional hazards model, an infrapopliteal calcium score of ≥188 was associated with a hazard ratio of 5.58 for CLTI or death (P = .0095). LECS = lower-extremity calcium score.

Summary

Vascular calcification is a key feature of atherosclerotic cardiovascular disease, the leading global cause of morbidity and mortality. In peripheral artery disease (PAD), calcification in the lower extremities correlates with increased severity of ischemia and heightened risk of amputation. Despite evidence linking calcification in specific segments to adverse outcomes, the relationship between calcification at different anatomical sites and peripheral artery disease symptom severity remains unclear. This knowledge gap is particularly relevant as current guidelines recommend intervention only at advanced stages of peripheral artery disease symptoms. There is a need for quantitative markers. This study aims to establish associations between computed tomography-based lower-extremity calcium scores and peripheral artery disease symptom presence and severity, to enhance risk assessment and facilitate timely intervention.

This study utilized a multi-institutional database to evaluate patients who underwent CT angiography of the aorta and bilateral lower-extremity runoff between January 2016 and January 2020. Patients were categorized based on documented symptoms, including claudication, ischemic rest pain, and ulcers. A total of 139 patients met inclusion criteria. Lower-extremity calcium scores (LECSs) were quantified using the Agatston method on CT angiography images. Additionally, ankle-brachial index (ABI) and toe-brachial index (TBI) values obtained within 6 months of the CT scan were included. The optimal cutoff point for infrapopliteal calcium score in identifying patients with chronic limb-threatening ischemia (CLTI) was determined using the Youden J statistic and validated using bootstrapping technique. A prospective cohort of claudicants was followed until October 2022 for CLTI and all-cause mortality.

Multivariable analysis identified only hemodialysis and lower ankle-brachial index (ABI) as independent factors associated with increased odds of claudication. Lower-extremity calcium score in any of the anatomic segments was not independently associated with having claudication. On the other hand, multivariable analysis confirmed the independent association of high infrapopliteal calcium scores with CLTI, along with inability to perform daily activities and absence of hemodialysis dependence. Receiver operating characteristic analysis demonstrated improved predictive accuracy for CLTI when including infrapopliteal calcium scores in the model. Prospective follow-up of claudicants revealed that those with infrapopliteal calcium scores ≥188 Agatston units had a significantly higher risk of progressing to CLTI or death compared to those with lower scores. Cox proportional hazards analysis confirmed infrapopliteal calcium score as a robust predictor of CLTI-free survival, even after adjusting for potential confounders.

Arterial calcification is an independent risk factor for cardiovascular morbidity and mortality, but its impact on lower-extremity vasculature remains less understood. CT-based quantification of lower-extremity arterial calcification provides valuable information for risk stratification in PAD patients. Higher infrapopliteal calcium scores may identify patients at earlier stages of disease progression, enabling timely interventions to prevent CLTI and associated adverse outcomes.

Limitations of the study include its small sample size and retrospective design. Additionally, certain factors such as hemodialysis and surgical bypass procedures may confound the associations observed. Further prospective studies with larger cohorts are needed to validate the utility of infrapopliteal calcium score in evaluating peripheral arterial disease progression and guiding clinical management.

Commentary

This is a well done and well written study on the clinical utility of CT lower extremity calcium score for the evaluation of peripheral arterial disease. The methods and statistical analyses were appropriate and the prospective validation was appreciated. The findings have several implications for the management of peripheral arterial disease. First, infrapopliteal calcium score can serve as a prognostic indicator, enabling clinicians to identify claudicants who are at highest risk of disease progression. Second, infrapopliteal calcium scores can inform clinical decision-making regarding the timing and type of interventions. Overall, this study underscores the potential of CT-based lower-extremity arterial calcium score as a valuable tool in the evaluation and management of peripheral arterial disease. Further research and validation studies are warranted to confirm these findings and integrate infrapopliteal calcium scoring into clinical practice effectively.

Percutaneous Lumbar Discectomy (PLD)

Patient-Reported Outcomes and Return to Work after CT-Guided Percutaneous Lumbar Discectomy: A Prospective Study

Clinical question

What capabilities does percutaneous lumbar discectomy have in reducing pain and increasing functional capacities for patients with symptomatic lumbar disc herniation?

Take away point

87% of employed patients were able to return to work during the follow-up, with a median time of 8 days post procedure.

Reference

Ranc, P.-A., Rudel, A., Bentellis, I., Prestat, A., Elbaze, S., Sala, V., Torre, F., Pavan, L.-J., Uri, I. F., & Amoretti, N. (2024). Patient-reported outcomes and return to work after CT-guided percutaneous lumbar discectomy: A prospective study. Journal of Vascular and Interventional Radiology, 35(3), 390–397. https://doi.org/10.1016/j.jvir.2023.12.007

https://www.jvir.org/article/S1051-0443(23)00896-5/fulltext

Study design

Prospective, observational, descriptive

Funding Source

None

Setting

Academic single center, Pasteur 2 Hospital University Medical Center (Nice, France)

Figure

Evolution of the Oswestry disability index (ODI) during the first 6 months

Summary

The purpose of this study was to understand the effectiveness of percutaneous lumbar discectomy under combined CT and fluoroscopic guidance, specifically its effects on pain relief, the length of recovery through hospital stays and/or time taken to return to work. Evaluation of patient-reported outcomes based on validated functional disability indices was also performed.

This study had 87 patients, 57 of which were employed with a median age of 56. The criteria were lumbar radicular pain visualized on magnetic resonance, failure of conservative treatment, and failure or recurrence after a peri-radicular nerve block. Patients were excluded if they had lumbar stenosis, neurologic deficits, or history of previous surgical discectomy at site of pain.

An initial planning CT was obtained to determine the access and approach for the procedure. Transdural or juxtadural access were preferred for central canal zone or subarticular zone hernias, and posterolateral or lateral approaches for herniation of foraminal and extraforaminal topography. 20-gauge guide needle was introduced to the herniated disc with contrast confirmation of its position. The Herniatome decompression probe was utilized for fragmentation and aspiration. Technical success was defined by correct targeting and tactile feedback.

The data gathered included pain measurements with visual analog scale, duration of the symptoms up to 1 year before treatment, the treated lumbar level, and topography of the herniated disc. The Oswestry disability index was obtained by questionnaire to evaluate the degree of functional disability. The participants were followed-up at 1-month interval with a lumbar MRI to evaluate any complications, then at 3 and 6 months through a blinded observer call.

The median Oswestry disability index decreased from 44 to 20 in 1 month, to 12 within 3 months, and to 7 at 6 months showing a significant increase in functionality (P < .001). At the end of follow-up, for 85% of the patients a decrease in visual analog scale score of >50% was found. With regard to the length of hospital stay, 96.5% were discharged on the same day of procedure, with the remaining patients being discharged the next day. Of the 57 actively working patients, 50 (88%) returned to work after a median time of 8 days. There were no major adverse events.

These results were consistent with those of the study by Liu et al, which evaluated the evolution of Oswestry disability index as well as differences in patients treated with endoscopic discectomy vs. percutaneous discectomy. McCormick et al also showed a 30% decrease in Oswestry indices with a different decompression probe. Ultimately, this study showed a significant decrease in the Oswestry disability index and an improvement in functional capacities after CT-guided percutaneous lumbar discectomy, leading to a faster return to work time which translates to higher patient satisfaction and decreased socioeconomic burden.

Commentary

In light of the increased incidence of younger adults developing disc herniation, this study highlights the medical and economic benefits of minimally invasive techniques in patients with refractory herniated disc syndromes. The effectiveness profile of percutaneous lumbar discectomy was comparable to previously published retrospective studies. But the current prospective study enabled evaluation of the socioeconomic impact. The methods of study were adequate in providing both qualitative and quantitative analyses. Nonetheless, as the authors rightly noted, a control group to analyze the differences compared to surgical or conservative methods would provide more real-world implications. It is clear from the data though that percutaneous lumbar discectomy has clinical and economic significance as illustrated by the median visual analog score decrease of 6 and median return-to-work time of 8 days. Minimally invasive percutaneous approaches are powerful and cost-effective additions to the refractory herniated disc management toolkit.

Post Author

Christopher Loiselle, MS, OMSIV
Lincoln Memorial University-DeBusk College of Osteopathic Medicine
@Caloiselle

Magnetic Anastomosis for Ureteral Obstruction

Magnetic Compression Anastomosis of Benign Short-Segment Ureteral Obstruction

Clinical Question

Is magnetic compression anastomosis safe, effective and feasible in benign short-segment ureteral obstruction.

Take Away Point

Magnetic compression anastomosis is safe and effective technique in combating the short benign ureteral obstruction demonstrating over 90% successful technical rate and no adverse events.

Reference

Ünal E, Çiftçi TT, Akinci D. Magnetic compression anastomosis of benign short-segment ureteral obstruction. Journal of Vascular and Interventional Radiology. 2024;35(3):398-403. doi:10.1016/j.jvir.2023.11.020

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Study Design

Retrospective, observation, descriptive study

Funding Source

No reported funding

Setting

Academic, Hacettepe University School of Medicine, Ankara, Turkey

Figure

Figure 2. A 48-year-old woman with previous history of surgery and radiotherapy for cervical carcinoma developed right hydroureteronephrosis. Cystoscopy-guided ureteral double-J stent placement performed at an outside hospital resulted in misplacement of a double-J stent into the lumen of the inferior vena cava (Video 1, available online at www.jvir.org). Perforation and false passage through the retroperitoneal space resulted in a diffusely narrowed ureter. (a) First, retrograde ureteral access was gained (white arrowheads) with the support of a vascular sheath (black arrow) and angled 5-F catheter (white arrow). (b) Anterograde access was obtained through the indwelling nephrostomy (not shown), and both access routes were used to reach the stricture (arrowheads). The short ureteral obstruction could not be traversed from the anterograde or retrograde access. (c) Magnets were pushed over the stiff guide wires to the ureteral obstruction as far as possible (arrows). (d) When the magnets were close enough to each other, they coupled and exerted pressure on the intervening tissue. On the fourth day, apposition of the magnets was evident radiographically. After magnetic compression anastomosis, the ureteral obstruction could be traversed by a guide wire. (e) Biopsy forceps were advanced through the lumen of a long vascular sheath (arrow) to push or to grab the magnets. (f) The magnets were pushed through the bladder and out of the urethra via through-and-through access (arrow). (g) Magnets (arrowheads) adhered to the guide wire (Amplatz, arrow) because of the ferromagnetic composition of the core and windings of the guide wire. (h) Finally, a double-J stent was placed from below, and the percutaneous nephrostomy tube was removed.

Summary

Magnetic compression anastomosis is becoming more popular due to its effectiveness and ease in tackling certain pathologies such as biliary strictures. The authors of this paper decided to investigate the feasibility, effectiveness, and safety of this technique against benign short-segment ureteral strictures with failed antegrade and retrograde recanalization attempts for double-J stent placement. Favorable results would allow significant improvement in patient’s quality of life, especially among those whom surgery is contraindicated or would otherwise have to tolerate a permanent nephrostomy tube with interval exchanges.

The authors performed a retrospective observational study across the time span from March 2018 to June 2022. Inclusion criteria was the presence of benign ureteral stricture and for whom surgery was contraindicated. Exclusion criteria were as follows: less than 18 years of age, malignant ureteral obstruction, length of ureteral gap of stricture exceeding magnet’s attraction capacity, and urinary tract infection refractive to medical therapy. The study comprised of 11 patients (3 male and 8 female), all of whom had indwelling nephrostomy tubes and had prior difficulty with anterograde/retrograde ureter stent placement. 5 of these patients had ileal conduits.

Technical success rate was defined as successful adherence of the magnets and subsequent ureteral stent placement. Adverse events were classified according to Society of Interventional Radiology classification system. The following parameters were also recorded: length of time of magnetic adherence, single-rotation fluoroscopy times of first and second steps procedure.

The first and second steps of the procedure are summarized below.

First step:
Both retrograde and anterograde access were performed to place the magnets in their respective positions. A combination of hydrophilic wire, 9 French vascular sheath, and 5 French 45 degrees angled catheter was used to gain access into the ureters via retrograde approach with eventual exchange to a stiff guidewire to place the magnet in the caudal portion of the stricture. A combination of 5 French catheter and hydrophilic wire was used during anterograde approach to reach the cranial part of the stricture for placement of the second magnet via stiff guidewire. Magnets’ positions relative to each other were evaluated using serial abdominal plain films until adherence was achieved.

Second step:
Anterograde and retrograde accesses were achieved in the ureters in the same manner as from the first step. Hydrophilic wire was used to traversed the magnets, with contrast injection confirming successful traversal. Balloon catheters or forceps were then used to remove the magnets, either by push or pull maneuvers through the urethra using a through-and-through access stiff guidewire. Afterwards, balloon dilatation was performed at the magnetic compression site and either 8 French double J stent or 8-12 French biliary drainage catheter was placed. Nephrostomy catheters were removed, and no antibiotics were given prior to patient discharge.

Technical success was 91% with no adverse events. 73% of the patients developed microscopic hematuria after the procedure which resolved within 72 hours. The mean time for magnetic adherence was 5.7 days. The mean fluoroscopic time for the first step was 9.45 minutes and the mean time for the second step was 15.7 minutes.

The reason this procedure works is that the magnets cause ischemia of the intervening tissues. The remaining tissues eventually adhere to each other and recanalization is achieved without compromising the integrity of the ureter. This optimizes the chances of subsequent intraluminal guidewire traversal, unlike other procedures such as the rendezvous technique which risks extraluminal traversal.

The study referenced several limitations, namely the retrospective design and the small patient population with only preliminary results provided. The author also emphasized the importance of proper patient selection for this technique as it is potentially useful in only limited context, such as the length of the stricture being within the capacity of the magnets.

Commentary

Magnetic compression anastomosis is not only a cool concept, but is also elegant and efficient when tackling certain problems. As a resident, I lost count of the times I saw my attending frustratingly attempting to pass strictures. Now I wonder how many of those cases could have been ameliorated by this technique, how much shorter the procedural times would have been, and how much radiation we could have minimized.

One thing not to gloss over is the importance of follow-up. The potential long-term complications of intra-abdominal magnets can be dreadful. Other than the abovementioned exclusion criteria, patients who have trouble with medical management compliance may not be optimal candidates for this technique. In the article’s defense, the data presented thus far are preliminary data, inviting opportunities for further research and optimal patient selection can be investigated in future studies.

Post author

Naeem Patel, DO
Radiology Resident, PGY4
Department of Radiology, Interventional Radiology Division
Hartford Hospital, Hartford, CT
@Naeemp7Patel