Stabilization of Rapidly Progressive Cardiac Allograft Vasculopathy Using mTOR Inhibition After Heart Transplantation.

BACKGROUND: Inhibition of the mammalian target of rapamycin (mTor) pathway after heart transplantation has been associated with reduced progression of coronary allograft vasculopathy (CAV). The application of low-dose mTOR inhibition in the setting of modern immunosuppression, including tacrolimus, remains an area of limited exploration. METHODS: This retrospective study included patients who received heart transplantation between January 2009 and January 2019 and had baseline, 1-year and 2-3-year coronary angiography with intravascular ultrasound (IVUS). Intimal thickness in 5 segments along the left anterior descending artery was compared across imaging time points in patients who were transitioned to low-dose mTOR inhibitor (sirolimus) vs standard treatment with mycophenolate on a background of tacrolimus. Long-term adverse cardiovascular outcomes (revascularization, severe CAV, retransplant, and cardiovascular death) were also assessed. RESULTS: Among 216 patients (mean age 51.5 ± 11.9 years, 77.8% men, 80.1% white), 81 individuals (37.5%) were switched to mTOR inhibition. mTOR inhibition was associated with a reduction in intimal thickness by 0.05 mm (95% CI 0.02-0.07; P < 0.001). This reduction was driven by patients who met the criteria for rapidly progressive CAV 1-year post-transplant (0.12 mm; P = 0.016 for interaction). After a median follow-up of 8.6 (IQR 6.6-11) years, 40 patients had major adverse cardiovascular outcomes. The use of mTOR inhibitors was not significantly associated with cardiovascular outcomes (P = 0.669). CONCLUSION: Transitioning patients after heart transplantation to an immunosuppression regimen composed of low-dose mTOR inhibition and tacrolimus was associated with a lack of progression of CAV, particularly in those with rapidly progressive CAV at 1 year, but not with long-term cardiovascular outcomes.

PCSK9 and Coronary Artery Plaque-New Opportunity or Red Herring?

PURPOSE OF REVIEW: Although the clinical benefit of reducing low-density lipoprotein cholesterol (LDLc) in patients with coronary artery disease (CAD) is well-established, the impact on plaque composition and stability is less clear. Our narrative review aimed to assess the clinical effects of proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors on coronary plaque characteristics specifically focusing from atheroma progression to regression and stabilization. RECENT FINDINGS: The combination of statin therapy and PCSK9 inhibitors (evolocumab and alirocumab) promotes plaque stability in patients following an acute coronary syndrome. The GLAGOV study highlighted the relationship between achieved LDLc levels and changes in percentage atheroma volume. Similarly, the PACMAN-AMI study concluded that the qualitative and quantitative changes in coronary plaque were associated with the levels of LDLc. Assessing the severity of coronary artery stenosis and the extent of atherosclerotic burden by means of imaging techniques (e.g., IVUS, OCT and near-infrared spectroscopic) have significantly advanced our understanding of the benefits from promoting plaque regression and achieving to features of plaque stabilization through increasingly intensive lipid-lowering strategies.

Outcomes of ultra-low contrast percutaneous coronary intervention in patients with advanced chronic kidney disease.

BACKGROUND: Coronary angiography and percutaneous coronary intervention (PCI) in patients with chronic kidney disease (CKD) is associated with increased risk of contrast induced nephropathy (CIN) and requirement for renal replacement therapy (RRT). OBJECTIVES: We aimed to evaluate our single center experience of ultra-low contrast PCI in patients with CKD and to characterize 1 year outcomes. METHODS: We performed a retrospective analysis of ultra-low contrast PCI at our institution between 2016 and 2022. Patients with CKD3b-5 (eGFR <45 mL/min/1.73m2), not on RRT who underwent ultra-low contrast PCI ( < 30 mL of contrast during PCI) were included. Primary outcomes included change in eGFR post-procedurally, and death, RRT requirement, and major adverse cardiac events (MACE) at 1 year follow-up. RESULTS: One hundred patients were included in the study. The median age was 67 years old and 28% were female. The median baseline eGFR was 21.5 mL/min/1.73m2 (IQR 14.08-32.0 mL/min/1.73m2). A median of 8.0 mL (IQR 0-15 mL) of contrast was used during PCI. Median contrast use to eGFR ratio was 0.37 (IQR 0-0.59). There was no significant difference between pre-and postprocedure eGFR (p = 0.84). At 1 year, 8% of patients died, 11% required RRT and 33% experienced MACE. The average time of RRT initiation was 7 months post-PCI. Forty-four patients were undergoing renal transplant evaluation, of which 17 (39%) received a transplant. CONCLUSIONS: In patients with advanced CKD, ultra-low contrast PCI is feasible and safe with minimal need for peri-procedural RRT. Moreover, ultra-low contrast PCI may allow for preservation of renal function in anticipation of renal transplantation.

Successful revascularization of coronary occlusion due to lotus root-like plaques by IVUS-based real-time three-dimensional wiring using the tip detection method in a patient with cardiac arrest.

A 32-year-old man, who was treated for T-cell lymphoma, presented in cardiac arrest. He had been treated for heart failure with reduced ejection fraction. Veno-arterial extracorporeal membrane oxygenation was initiated immediately. We diagnosed him as non-ST elevated myocardial infarction. Coronary angiography demonstrated the occlusion of the trifurcation in the proximal left anterior descending artery (LAD). We failed to advance the first guidewire into the distal LAD by angio-based conventional wiring. Intravascular ultrasonography (IVUS) of the proximal diagonal branch revealed two diaphragms separating the distal lumen without connection, which looks like lotus root-like appearance. We quickly penetrated the plaque using IVUS-based real-time 3D wiring using the tip detection method. The contrast injection via the microcatheter showed the distal diagonal branch (D2). After the balloon dilation in D2, IVUS image revealed a torn plaque between D2 and the distal LAD. Subsequently we advanced the guidewire to the distal LAD using IVUS-based real-time 3D wiring using the tip detection method through the tear of the plaque. Finally, we successfully performed the revascularization of LAD in a preferable procedure time. The patient recovered well and was discharged 39 days after cardiac arrest. This case highlights the efficacy of IVUS-based real-time 3D wiring using the tip detection method even in the emergent and challenging situation.

Intravascular ultrasound-guided STAR 2.0: A new technique for chronic total occlusion recanalization.

The use of the subintimal space has allowed a massive advancement in the field of chronic total occlusion percutaneous coronary intervention (PCI). The STAR technique is the first of subintimal techniques. Despite a high acute success rate, follow-up results showed unfavorable outcomes with half of the treated patients showing restenosis/reocclusion at 6 months. We present three cases in which a modification of the STAR technique guided by intravascular ultrasound (IVUS), namely the STAR 2.0, was used as a bailout for successful PCI of chronic total occlusions.

Cardiovascular outcomes of complex bifurcation lesions following double kissing crush or nano-crush techniques: The multicenter EVOLUTE-CRUSH V study.

BACKGROUND: Double kissing crush (DKC) and nano-crush (NC) techniques are frequently used, but the comparison for both techniques is still lacking. The goal of this multicenter study was to retrospectively assess the midterm clinical results of DKC and NC stenting in patients with complex bifurcation lesions (CBLs). METHODS: A total of 324 consecutive patients [male: 245 (75.6%), mean age: 60.73 ± 10.21 years] who underwent bifurcation percutaneous coronary intervention between January 2019 and May 2023 were included. The primary endpoint defined as the major cardiovascular events (MACE) included cardiac death, target vessel myocardial infarction (TVMI), or clinically driven target lesion revascularization (TLR). Inverse probability weighting (IPW) was performed to reduce treatment selection bias. This is the first report comparing the clinical outcomes of DKC and NC stenting in patients with CBL. RESULTS: The initial revascularization strategy was DKC in 216 (66.7%) cases and NC in 108 (33.3%) patients. SYNTAX scores [25.5 ± 6.73 vs. 23.32 ± 6.22, p = 0.005] were notably higher in the NC group than the DKC group. The procedure time (76.98 ± 25.1 vs. 57.5 ± 22.99 min, p = 0.001) was notably higher in the DKC group. The incidence of MACE (18.5 vs. 9.7%, p = 0.025), clinically driven TLR (14.8 vs. 6%, p = 0.009), and TVMI (10.2 vs. 4.2%, p = 0.048) were notably higher in the NC group than in the DKC group. The midterm MACE rate in the overall population notably differed between the NC group and the DKC group (adjusted HR (IPW): 2.712, [95% CI: 1.407-5.228], p = 0.003). CONCLUSION: In patients with CBLs, applying the DKC technique for bifurcation treatment had better ischemia-driven outcomes than the NC technique.

Predictor of left main coronary artery size: an intravascular ultrasound study in Southeast Asia population.

Left main (LM) percutaneous coronary intervention (PCI) has expanded rapidly in the past decade, with up to fourfold increase annually. Recent trials found that intravascular imaging (IVI)-guided LM PCI resulted in lower risks of cardiac death and stent failure due to suboptimal PCI compared to angiography-guided PCI. IVI usage has increased in recent years; however, its utilization remains variable across regions and is still incredibly low in developing countries. Furthermore, to date, there is no data about LM size in the Southeast Asian population. This study aims to determine the mean external elastic membrane (EEM) diameter, cross-sectional area (CSA) of LM, and its predictor. This is a cross-sectional observational study on 100 patients with coronary artery disease (CAD) who underwent IVUS-guided PCI with a pullback to LM in Dr. Hasan Sadikin General Hospital Bandung, Indonesia, from January 2020 until December 2022. Linear regression was used to determine the predictors of LM size. There were 100 segments of LM. LM's mean EEM diameter and CSA were 5.02 ± 0.43 mm and 19.93 ± 3.48 mm2. Body surface area (BSA) is an independent predictor of EEM diameter and CSA with a positive linear relationship (p 0.001 and p 0.0001). Hypertension is an independent predictor of EEM diameter with a positive linear relationship (p 0.034). The linear equation to predict EEM diameter and CSA were (2.741 + 1.272BSA(m2) + 0.165 hypertension (yes)) and (2.745 + 9.601BSA(m2)), respectively. The LM coronary artery size of the Southeast Asian population was comparable with the previous studies. BSA and hypertension are independent predictors of EEM diameter, with BSA being stronger than hypertension. Neither sex nor other cardiovascular risk factors affect the LM size. The knowledge of coronary artery size will help the clinician have a reference for intervention, especially when no intravascular imaging is available.

Cost-effectiveness analysis of intravascular ultrasound-guided peripheral vascular interventions in patients with femoropopliteal peripheral artery disease.

Background: Intravascular ultrasound (IVUS)-guided percutaneous transluminal angioplasty (PTA) might offer clinical benefits compared to angiography-guided PTA in patients with peripheral artery disease (PAD). A cost-effectiveness model was developed to examine the benefits and costs of IVUS-guided PTA versus angiography-guided PTA in PAD patients with femoropopliteal (FP) occlusive disease. Methods: A two-step model (a one-year decision tree followed by a lifetime semi-Markov model) was developed from a German healthcare payer perspective to estimate the costs and outcomes over a one-year and lifetime horizon. Clinical events included target lesion revascularization (TLR), amputation, and death. Transition probabilities and utility values were derived from published literature. Healthcare costs were based on German Diagnosis Related Groups (DRG) codes. Costs and outcomes were discounted at a rate of 3% per year. The incremental cost-effectiveness ratio (ICER) was calculated, and sensitivity analyses were performed to assess the robustness of the results. Results: In the one-year horizon, IVUS-guided PTA resulted in incremental quality-adjusted life-years (QALY) and costs of 0.02 and €919 per patient respectively, with a corresponding ICER of €45,195/QALY gained versus angiography-guided PTA. In the lifetime horizon, IVUS-guided PTA outperforms angiography-guided PTA; it was associated with a cost saving of €46 per patient and incremental QALY of 0.22. Utility value for post-TLR, as well as probabilities of death and TLR had the greatest impact on the one-year ICER, while cost of TLR and probabilities of TLR and amputation influenced the lifetime ICER most. The probability of IVUS-guided PTA being cost-effective at a willingness-to-pay (WTP) threshold of €50,000/QALY was 50.4% in the one-year horizon and increased to 85.9% in the lifetime horizon. Conclusions: In this analysis IVUS-guided PTA among patients with symptomatic FP atherosclerosis was cost-saving in a lifetime horizon from the German healthcare payer perspective.

Diagnostic Performance of 60 MHz High-Definition Intravascular Ultrasound versus Fourier Domain Optical Coherence Tomography for Identifying Plaque Rupture, Plaque Erosion, and Thrombosis in a Rabbit Model.

Background: Most acute coronary syndromes occur due to coronary thrombosis caused by plaque rupture (PR) and plaque erosion (PE). Precise in vivo differentiation between PR and PE is challenging for intravascular imaging. This study is the first to determine the diagnostic performance of the novel 60 MHz high-definition intravascular ultrasound (HD-IVUS) for differentiating atherosclerotic plaque morphology influenced by local hemodynamic flow in rabbits. This study evaluated the diagnostic performance of 60 MHz HD-IVUS in identifying thrombosis in rabbits. Methods: We established 60 rabbit models of atherosclerosis with left common carotid artery (LCCA) stenosis and 30 FeCl 3 -induced LCCA thrombosis. Intravascular imaging was assessed with 60 MHz HD-IVUS and fourier-domain optical coherence tomography (FD-OCT). The present study investigated the diagnostic accuracy of 60 MHz HD-IVUS for PR and PE, as well as thrombosis, using OCT-diagnosis as a standard reference. Results: 60 MHz HD-IVUS for identifying atherosclerotic plaque morphology using plaque cavity and minor intimal irregularities showed high sensitivity and specificity; 92.0 and 90.0% for identifying OCT-defined PR, and 80.0 and 70.0% for OCT-defined PE, respectively. In a rabbit thrombus model, 60 MHz HD-IVUS showed high sensitivity (88.0%) and specificity (80.0%) in identifying OCT-defined thrombosis. Conclusions: 60 MHz HD-IVUS can accurately identify PR and thrombosis. Further studies should confirm the clinical value of this novel technique in PE diagnosis.

Imaging of Left Main Coronary Artery; Untangling the Gordian Knot.

Left Main Coronary Artery (LMCA) disease is considered a standout manifestation of coronary artery disease (CAD), because it is accompanied by the highest mortality. Increased mortality is expected, because LMCA is responsible for supplying up to 80% of total blood flow to the left ventricle in a right-dominant coronary system. Due to the significant progress of biomedical technology, the modern drug-eluting stents have remarkably improved the prognosis of patients with LMCA disease treated invasively. In fact, numerous randomized trials provided similar results in one- and five-year survival of patients treated with percutaneous coronary interventions (PCI) -guided with optimal imaging and coronary artery bypass surgery (CABG). However, interventional treatment requires optimal imaging of the LMCA disease, such as intravascular ultrasound (IVUS) and optical coherence tomography (OCT). The aim of this manuscript is to review the main pathophysiological characteristics, to present the imaging techniques of LMCA, and, last, to discuss the future directions in the depiction of LMCA disease.

Intravascular coronary lithotripsy for the treatment of iatrogenic calcium embolization: The "block and crack" technique.

Intracoronary calcium embolization during percutaneous procedure is a very rare and unpredictable event, that  can lead to serious complications and even expert operators could face some technical issues to solve it. This case report presents a technique called "block and crack" used to manage iatrogenic intracoronary calcium embolization of left anterior descending coronary artery. The technique involves implanting a drug eluting stent (DES) to block the embolus against the vessel wall, followed by the use of lithotripsy balloon inflated inside the DES to crack the calcium and achieve a better stent expansion. This technique allowed to avoid further distal calcium embolization as well as to minimize residual stenosis degree after stent implantation.

Comparison of intravascular ultrasound, optical coherence tomography, and conventional angiography-guided percutaneous coronary interventions: A systematic review, network meta-analysis, and meta-regression.

BACKGROUND: Intracoronary imaging modalities, including intravascular ultrasound (IVUS) and optical coherence tomography (OCT), provide valuable supplemental data unavailable on coronary angiography (CA) and have shown to improve clinical outcomes. We sought to compare the clinical efficacy of IVUS, OCT, and conventional CA-guided percutaneous coronary interventions (PCI). METHODS: Frequentist and Bayesian network meta-analyses of randomized clinical trials were performed to compare clinical outcomes of PCI performed with IVUS, OCT, or CA alone. RESULTS: A total of 28 trials comprising 12,895 patients were included. IVUS when compared with CA alone was associated with a significantly reduced risk of major adverse cardiovascular events (MACE) (risk ratio: [RR] 0.74, 95% confidence interval: [CI] 0.63-0.88), cardiac death (RR: 0.64, 95% CI: 0.43-0.94), target lesion revascularization (RR: 0.68, 95% CI: 0.57-0.80), and target vessel revascularization (RR: 0.64, 95% CI: 0.50-0.81). No differences in comparative clinical efficacy were found between IVUS and OCT. Rank probability analysis bestowed the highest probability to IVUS in ranking as the best imaging modality for all studied outcomes except for all-cause mortality. CONCLUSION: Compared with CA, the use of IVUS in PCI guidance provides significant benefit in reducing MACE, cardiac death, and revascularization. OCT had similar outcomes to IVUS, but more dedicated studies are needed to confirm the superiority of OCT over CA.

Multimodality imaging results of TAP versus novel modified TAP stenting in coronary bifurcation: From bench testing to first-in-man investigation.

OBJECTIVES: We investigated the results of T and small protrusion (TAP) versus a novel modification of TAP (mTAP) stenting by multimodality imaging in bench testing and in patients with coronary bifurcation lesions (CBL). BACKGROUND: TAP stenting is a suboptimal technique for bailout side branch (SB) stenting. METHODS: In a bench model, optical coherence tomography (OCT), microscopic examinations (ME), and computational fluid dynamics (CFD) were performed after TAP and mTAP stenting. In 20 patients with CBL, 80 intravascular ultrasound (IVUS) examinations were performed during mTAP stenting in which the SB stent was pulled-back to indent the inflated main vessel (MV) balloon and deployed while deflating it. For TAP stenting, the tip of the SB stent was positioned in the MV and deployed. RESULTS: In bench testing, OCT showed neocarina length (NL) was shorter and minimum stent area (MSA) was larger after mTAP versus TAP stenting (2.84 ± 0.70 vs. 4.80 ± 020 mm; 6.75 ± 1.50 vs. 4.5 ± 2.2 mm2 ; respectively; p < 0.05). By ME, NL was shorter and shear rate trended lower after mTAP versus TAP stenting. In patients, IVUS showed MSA was larger after versus before mTAP stenting (6.32 ± 0.58 vs. 5.21 ± 0.56 mm2 ; p < 0.01); NL was 1.43 ± 0.22 mm with SB ostium coverage. The Seattle Angina questionnaire (SAQ) score was higher at 6 months versus baseline (85 ± 4.0 vs. 48 ± 6.0, respectively; p < 0.001). CONCLUSIONS: This multimodality imaging study showed, for the first time, mTAP stenting resulted in larger stent area and shorter neocarina than TAP stenting in bench testing. In patients with CBL, mTAP stenting led to larger stent area, short neocarina with complete SB ostium coverage, and improved the SAQ score at follow-up.

Modified leopard-crawl technique using intravascular lithotripsy balloon in calcified coronary lesions.

Intravascular lithotripsy (IVL) has emerged as a novel therapy for the treatment of coronary calcification. Numerous studies have reported the safety and efficacy of IVL in calcified coronary lesions, while IVL balloon-uncrossable calcified coronary lesions are sometimes encountered in clinical practice. This case report represents a novel technique called "modified leopard-crawl" to advance the IVL balloon antegradely by creating significant calcium cracking forward when the enhanced stent visualization system reveals that the distal emitter seems adjacent to calcification. This technique might be a valuable alternative when conventional procedures fail and has the potential to enhance the clinical applicability of IVL in daily practice.

Intracoronary imaging guided percutaneous coronary intervention outcomes among individuals with cardiogenic shock.

BACKGROUND: Limited data exist around the utility of intracoronary imaging (ICI) during percutaneous coronary intervention (PCI) in patients with acute coronary syndrome (ACS) and cardiogenic shock (CS), who are inherently at a high risk of stent thrombosis (ST). METHODS: All PCI procedures for ACS patients with CS in England and Wales between 2014 and 2020 were retrospectively analysed, stratified into two groups: ICI and angiography-guided groups. Multivariable logistic regression analyses were performed to examine odds ratios (OR) of in-hospital outcomes, including major adverse cardiovascular and cerebrovascular events (MACCE; composite of all-cause mortality, acute stroke/transient ischaemic attack (TIA), and reinfarction) and major bleeding, in the ICI-guided group compared with angiography-guided PCI. RESULTS: Of 15,738 PCI procedures, 1240(7.9%) were ICI-guided. The rate of ICI use amongst those with CS more than doubled from 2014 (5.7%) to 2020 (13.3%). The ICI-guided group were predominantly younger, males, with a higher proportion of non-ST-elevation ACS and ST. MACCE was significantly lower in the ICI-guided group compared with the angiography-guided group (crude: 29.8% vs. 38.2%, adjusted odds ratio (OR) 0.65 95% confidence interval [CI] 0.56-0.76), driven by lower all-cause mortality (28.6% vs. 37.0%, OR 0.65 95% CI 0.55-0.75). There were no differences in other secondary outcomes between groups. CONCLUSION: ICI use among CS patients has more than doubled over 6 years but remains significantly under-utilized, with less than 1-in-6 patients in receipt of ICI-guided PCI by 2020. ICI-guided PCI is associated with prognostic benefits in CS patients and should be more frequently utilized to increase their long-term survival.

Anomalous right coronary artery originating from the opposite sinus of Valsalva: Fractional flow reserve and intravascular ultrasound-guided management.

There remains significant controversy in the risk stratification and management of patients with anomalous right coronary artery originating from the opposite sinus (R-ACAOS). We present the case of a patient with an inferior ST-elevation myocardial infarction, found to have R-ACAOS and severe atherosclerotic right coronary artery disease, treated with fractional flow reserve and intravascular ultrasound-guided percutaneous coronary intervention.

Clinical and procedural outcomes of percutaneous coronary intervention for de novo lesions involving the ostial left circumflex coronary artery.

BACKGROUND: Percutaneous treatment for ostial left circumflex artery (LCx) lesions is known to be associated with suboptimal results. AIMS: The present study aims to assess the procedural and long-term clinical outcomes of percutaneous coronary intervention (PCI) for de novo ostial LCx lesions overall and according to the coronary revascularization strategy. METHODS: Consecutive patients undergoing PCI with second generation drug eluting stents or drug coated balloons for de novo ostial LCx lesions in three high-volume Italian centers between 2012 and 2021 were retrospectively evaluated. The primary endpoint was target-vessel revascularization (TVR) at 2 years. Secondary endpoints included major adverse cardiovascular and cerebrovascular events (MACCE), target lesion revascularization, myocardial infarction, stroke, all-cause death, and repeat revascularization. RESULTS: A total of 366 patients were included in the analysis with a median follow-up of 901 (IQR: 450-1728) days. 79.5% of the patients were male, 33.6% were diabetic, 49.7% had a previous PCI, and 23.1% a prior surgical revascularization. Very ostial LCx stenting was performed in 34.1%, crossover from left main to LCx in 17.3%, and a two-stent strategy in 48.6% of cases, respectively. In the overall population, the incidence of TVR at 2 years was 19.0% while MACCE rate was 25.7%. No major differences in clinical outcomes were found according to the stenting strategy. Use of intracoronary imaging was associated with fewer MACCE (HR: 0.47, 95% CI: 0.25-1.13, p = 0.01), while the diameter of the stent implanted in the ostial LCx was associated with less TVR (HR: 0.43, 95% CI: 0.25-0.75, p = 0.002). CONCLUSIONS: Percutaneous revascularization of the ostial LCx is associated with a high rate of TVR, regardless of the stenting strategy. Intracoronary imaging and proper stent sizing may reduce the failure rates.

Zero-contrast IVUS-guided complex PCI in a patient with NSTE-ACS and severe renal impairment.

A 76-year-old male with severe comorbidities and multiple cardiovascular risk factors including stage IV chronic kidney disease presents with non-ST-elevation myocardial infarction. An ultra-low contrast invasive coronary angiography using the DyeVert system and iso-osmolar contrast agent revealed a multivessel disease with heavy calcifications involving the left main stem and its bifurcation requiring a complex percutaneous coronary intervention. Because of the high risk of contrast-induced acute kidney injury, a zero-contrast intervention was performed using intravascular ultrasound guidance and dedicated stenting techniques with optimal imaging, clinical, and renal outcomes. Zero-contrast policies can be safely implemented even in complex clinical scenarios but at least two orthogonal angiographic projections should always be acquired to rule out distal complications.

Intravascular Ultrasound Versus Computed Tomography Angiography in Sizing and Operative Management of Endovascular Aortic Aneurysm Repair.

OBJECTIVES: An abdominal aortic aneurysm (AAA) is a potentially life-threatening condition, the management of which has dramatically evolved over the past 2 decades with an increasing tendency toward endovascular repair (EVAR) rather than open surgical repair. Classically, contrast-enhanced multislice computed tomography (CT) angiography (CTA) is performed preoperatively for procedure sizing and EVAR planning. This entails voluminous contrast injection with risk of allergic reaction, nephropathy, and radiation exposure. Intra-vascular ultrasound (IVUS) has been increasingly used to guide EVAR procedures intraoperatively. The aim of this study is to investigate the accuracy of IVUS in sizing AAAs, device selection, and EVAR planning compared to the gold standard CTA. DESIGN: This is a prospective observational study enrolling 10 patients who underwent standard infrarenal EVAR procedures performed for unruptured infrarenal AAAs over the course of 1 year. All patients had a preoperative CTA done upon which aneurysm sizing and device planning were performed, and the measurements obtained were compared to those obtained from intraoperative IVUS. METHODS: All participating patients had unruptured infrarenal AAA, had no renal impairment, and had anatomical suitability for EVAR according to the instructions for use (IFU) of the device manufacturer. Primary endpoint was comparing anatomical measurements recorded by IVUS with those obtained from the preoperative CTA. RESULTS: Mean age was 65.6 (±6.19), all patients were males and hypertensives and 4 (40%) had a positive family history for AAA. On comparing mean measurements taken by CTA and IVUS, there was no statistically significant differences with exception of maximal aortic diameter and aortic diameter at site of bifurcation (both p-values <.001). There were no statistically significant differences in length measurements between the 2 imaging modalities. Computed tomography angiography was more associated with neck thrombus detection, and IVUS was more associated with calcification detection. CONCLUSION: Although CT angiography is still the gold standard imaging modality for AAA, IVUS use is very beneficial in EVAR sizing and planning, in addition to intra-operative guidance of the procedure, saving the patient significant time, contrast administration, and radiation exposure, especially in patients with renal impairment and contrast allergy. CLINICAL IMPACT: A preoperative CT angiogram is the gold standard required investigation for planning and sizing EVARs, with subsequent contrast injection entailing a risk of contrast induced nephropathy and allergic reactions. IVUS has been used as an adjuvant technique to guide EVAR stent graft deployment. However, our study concluded that it can also be reliably used in sizing and planning of the EVAR stent graft along with complementary non contrast imaging, especially in patients with high risk for contrast induced nephropathy and contrast allergy.

Preprocedural imaging modalities in patients undergoing iliocaval venous recanalization and stent placement.

PURPOSE: To determine the diagnostic accuracy of preinterventional imaging modalities in patients being evaluated for iliocaval venous recanalization and stent placement. METHODS: Consecutive patients with iliocaval postthrombotic obstructions or nonthrombotic iliac vein lesions (NIVL), who were scheduled for recanalization, underwent duplex ultrasound (DUS), magnetic resonance venography (MRV), multiplanar venography (MPV), and intravascular ultrasound (IVUS). The diagnostic accuracies of DUS, MRV, and MPV were analyzed using IVUS as reference. RESULTS: A total of 216 limbs in 108 patients (80 patients with postthrombotic obstructions, 28 patients with NIVL) were examined. In patients with postthrombotic obstructions, the diagnostic sensitivities for the detection of lesions of the common femoral vein were 81% (95% CI 71-89%) for DUS, 76% (95% CI 65-85%) for MRV, and 86% (95% CI 76-93%) for MPV. The sensitivities for detecting lesions of the iliac veins were 96% (95% CI 89-99%) for DUS, 99% (95% CI 92-100%) for MRV, and 100% (95% CI 94-100%) for MPV. Regarding the inferior vena cava, the sensitivities were 44% (95% CI 24-65%) for DUS, 52% (95% CI 31-73%) for MRV, and 70% (95% CI 47-86%) for MPV. The sensitivities for detecting NIVL were 58% (95% CI 34-79%) for DUS, 90% (95% CI 68-97%) for MRV, and 95% (95% CI 73-99%) for MPV. CONCLUSION: In patients scheduled for recanalization of iliocaval postthrombotic obstructions, the sensitivities of DUS, MRV, and MPV were similar. In patients with suspected inferior vena cava involvement and in patients with NIVL, additional imaging with MR or conventional venography is required.