Amount Of Contrast Medium Research Articles

A method for improving iodine contrast enhancement in abdominal computed tomography: experimental study in a pig model

To investigate the improvement in diagnostic image quality of an iodine contrast enhancement tool in an animal model for computed tomography (CT). One pig was examined over several consecutive days with a CT system. The quantity of iodine as contrast medium (0.6-1.2 ml/kg) varied among different acquisitions. The contrast enhancement in the reconstructed slices was improved via a post-processing tool. The post-processing tool is an algorithm designed for enhancement of iodine contrast in CT data. Contrast-to-noise ratio (CNR), the detectability between soft-tissue and vascular structures, and quantitative image analysis were assessed. When reducing the quantity of contrast medium, our subjective image quality assessment revealed that it is visually possible to generate similar enhancement with less iodine. This observation was confirmed quantitatively in our CNR results. While employing the algorithm, the CNR between vascular structures and subcutaneous fat significantly improved. For unenhanced regions, we identified no change in HU values and no significant strengthening of artefacts. With post-processing there was a significantly improved diagnostic image quality compared with non-processed data. In particular, similar contrast enhancement could be achieved with a reduced quantity of contrast medium injected during the CT acquisition.

Three-Dimensional Guided Renal Denervation to Treat Drug-Resistant Arterial Hypertension in a Patient With Renal Insufficiency

HomeHypertensionVol. 60, No. 4Three-Dimensional Guided Renal Denervation to Treat Drug-Resistant Arterial Hypertension in a Patient With Renal Insufficiency Free AccessLetterPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissionsDownload Articles + Supplements ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toSupplemental MaterialFree AccessLetterPDF/EPUBThree-Dimensional Guided Renal Denervation to Treat Drug-Resistant Arterial Hypertension in a Patient With Renal Insufficiency Thorsten Lewalter and Turgut Brodherr Thorsten LewalterThorsten Lewalter Isar Heart Center Munich, Munich, Germany Search for more papers by this author and Turgut BrodherrTurgut Brodherr Isar Heart Center Munich, Munich, Germany Search for more papers by this author Originally published20 Aug 2012https://doi.org/10.1161/HYPERTENSIONAHA.112.201467Hypertension. 2012;60:e33Other version(s) of this articleYou are viewing the most recent version of this article. Previous versions: January 1, 2012: Previous Version 1 To the Editor:A 68-year–old diabetic women was transferred to our department for renal denervation to treat drug-resistant arterial hypertension. A known diabetic nephropathy deteriorated after an abdominal computed tomography scan in the external hospital with an increase of the serum creatinine (baseline, 1.3 mg/dL; 5 days after computed tomography, 2.1 mg/dL; at admission to our hospital, 1.4 mg/dL). To reduce or even eliminate the amount of necessary contrast medium during the denervation procedure we decided to perform a 3D guided ablation procedure.For this purpose, the external abdominal computed tomography scan was used to reconstruct the 3D anatomy of the renal arteries. The impedance-based NavX system (St Jude), used routinely in arrhythmia ablation, was used to create a virtual anatomy of both renal arteries by touching the vessel walls. For image fusion, critical anatomic landmarks like, for example, an orifice of the renal arteries or areas of vessel bifurcation, were determined by comparing the position of the catheter in the native x-ray and the 3D image based on computed tomography anatomy. A decapolar steerable electrode catheter in the renal venous system served as the local reference catheter (Figure A and B, video).Download figureDownload PowerPointFigure. Anterolateral view (A) and posterior view (B) of the 3D image of the renal artery (red), the renal vein (blue), and kidney parenchyma (gray). The reference decapolar catheter is positioned in a side branch of the renal vein. The ablation catheter can be located in the proximal portion of the renal artery. The green dots indicate ablation spots.To perform the ablation, a cooled tip 7F quadripolar radiofrequency ablation (IBI/St Jude) catheter with a flow of 17 mL/min and a maximum of 10 watts was used in a power-controlled mode (IBI/St Jude RF generator). In the right renal artery 11 ablation points and in the left 13 ablation points were delivered in a spiral manner from the distal until the proximal portion of both renal arteries. To check the distal catheter position once for the fusion process, a single contrast medium injection was performed in each renal vein (7 mL for the left and 8 mL for the right), leading to a total contrast medium volume of 15 mL for the entire procedure. To reduce the risk of vasospasm, we performed the procedure in deep sedation (propofol infusion). No creatinine increase could be detected after the ablation procedure. A postprocedural Doppler sonography of both renal arteries revealed no evidence for a stenotic process. At 3 months after the procedure, a drop in the mean systolic blood pressure of 9 mm Hg and in the mean diastolic pressure of 4 mm Hg in a 24-hour measurement could be documented.To our knowledge, this is the first report about a cooled tip renal denervation using a 3D nonfluoroscopic guiding system. This approach allows an ablation requiring only a minimal amount of contrast medium. Even a procedure without any contrast medium appears feasible with this technique. Therefore, this approach is of special interest in patients with drug-resistant arterial hypertension and concomitant renal insufficiency with the aim of reducing their exposure to contrast medium to a minimum.Thorsten LewalterTurgut BrodherrIsar Heart Center MunichMunich, GermanyFootnotesLetters to the Editor will be published, if suitable, as space permits. They should not exceed 1000 words (typed double-spaced) in length and may be subject to editing or abridgmentThe online-only Data Supplement is available with this article at http://hyper.ahajournals.org/lookup/suppl/doi:10.1161/HYPERTENSIONAHA.112.201467/-/DC1. Previous Back to top Next FiguresReferencesRelatedDetailsCited By Tölle M and van der Giet M (2013) Renale Denervation als Therapieoption, CardioVasc, 10.1007/s15027-013-0022-1, 13:1, (38-44), Online publication date: 1-Feb-2013. Xiao Y, Zhou S and Liu Q (2012) Ablation Points of Renal Sympathetic Denervation: The More, the Better?, Hypertension, 60:6, (e47-e47), Online publication date: 1-Dec-2012. October 2012Vol 60, Issue 4 Advertisement Article InformationMetrics © 2012 American Heart Association, Inc.https://doi.org/10.1161/HYPERTENSIONAHA.112.201467PMID: 22914794 Originally publishedAugust 20, 2012 PDF download Advertisement SubjectsArrhythmiasCatheter Ablation and Implantable Cardioverter-DefibrillatorHypertensionTreatment

Subarachnoid Hyperattenuation on Flat Panel Detector–Based Conebeam CT Immediately after Uneventful Coil Embolization of Unruptured Intracranial Aneurysms

Flat panel detector-based CBCT can provide CT-like images of the brain without transferring patients from the angiography suite to a conventional CT facility. Conventional brain CT after uneventful endovascular treatment sometimes shows focal subarachnoid hyperattenuation with contrast leakage, mimicking SAH. Differentiating this finding from SAH is important for immediate postprocedural medical management. We investigated CBCT for detecting subarachnoid hyperattenuation immediately after coil embolization of unruptured cerebral aneurysms. Thirty-six patients with unruptured cerebral aneurysms undergoing CBCT immediately after uncomplicated coil embolization were included. The relationship between the presence of subarachnoid hyperattenuation and total volume of contrast medium injected, aneurysm size and location, and balloon and stent assistance during embolization was investigated. Statistical analyses were performed with the χ(2) test (P < .05). Nine of the 36 patients (25.0%) showed focal subarachnoid hyperattenuation within the relevant parent artery territory harboring the aneurysm. Subarachnoid hyperattenuation locations included the ipsilateral superior frontal sulcus (n = 5), the bilateral superior frontal sulcus (n = 1), and the ipsilateral superior frontal and precentral sulci (n = 3). Statistically significant differences were observed between the presence of a subarachnoid hyperattenuation and the total volume of contrast medium injected (P < .001) and aneurysm size (P < .05). Subarachnoid hyperattenuation can be detected by CBCT immediately after coil embolization for unruptured aneurysms. The increased amounts of contrast medium to be given before CBCT and the specific location of the hyperattenuation may help differentiate benign subarachnoid contrast leakage from SAH.

Simultaneous Dual Vascular Access Site for the Treatment of Coronary Artery Bifurcation Lesions by Complex 2‐Stent Technique

To propose an original approach based on simultaneous dual vascular access site (DAS) using 2 small-size guiding catheters to easily perform complex 2-stent techniques for bifurcation coronary lesions (BL). Simultaneous kissing stenting and classic crush technique require large 7 or 8Fr guiding catheters leading to large amounts of contrast medium, vascular access site complications, and sometimes frictions or criss-cross of the 2-stent delivery systems. DAS was used in 30 patients with BL (11 radio-radial, 16 radio-femoral, and 3 femoro-femoral). Among 60 guiding catheters, the size was 5Fr in 28, 6Fr in 30, and 7Fr in 2 cases of double adjacent BL. When 2 different size catheters were used, contrast medium injections were done using the smallest size catheter. DAS patients were compared with a group of 30 BL patients treated using a single femoral vascular access site (SAS) with 7 or 8Fr catheters. Success rate was 100% in all patients. Contrast volume used was smaller in DAS than in SAS patients (277 ± 156 cc vs. 380 ± 165 cc,P = 0.01). No vascular access site complication occurred in the sub-group of the 11 DAS radio-radial patients. Postintervention hospitalization duration was shorter in DAS than in SAS (1.9 ± 2 vs. 2.8 ± 2 days,P = 0.048). DAS allows to successfully perform complex stenting technique of BL using small-size guiding catheters leading to decreased contrast medium volume, decreased vascular access site complications rates, and shortened hospitalization duration.

Anatomic Distribution of Gadolinium Contrast Medium by High-Resolution Magnetic Resonance Imaging After Peribulbar and Retrobulbar Injections

To examine the anatomic distribution of gadolinium contrast medium by high-resolution surface-coil magnetic resonance imaging after peribulbar and retrobulbar injection. Comparative case series in which 4 healthy volunteers were randomized to peribulbar (n = 2) or retrobulbar (n = 2) injection of gadolinium and lidocaine hydrochloride, 2%, without epinephrine. Magnetic resonance imaging was performed before injection and at 5 minutes and 90 minutes after injection. The peribulbar injection technique resulted in contrast medium primarily in the extraconal space, with no gadolinium observed at the orbital apex; surprisingly, a small amount of contrast medium was observed in the pterygopalatine fossa immediately after peribulbar injection. The retrobulbar injection technique resulted in gadolinium signal diffusely enhancing the intraconal space, orbital apex, optic nerve sheath, and optic canal. The signal intensity was clearly observed in the cavernous sinus surrounding the cavernous portion of the internal carotid artery. A small amount of contrast medium was detected in the pterygopalatine fossa. The retrobulbar injection technique localizes to the intraconal space, with access to intracranial and central nervous system structures via the optic canal, superior orbital fissure, and cavernous sinus. In contrast, the peribulbar injection technique produces a mostly extraconal distribution; however, intraconal solution may communicate with the central nervous system via the inferior orbital fissure and pterygopalatine fossa. This novel finding suggests that peribulbar anesthesia has a readily accessible route for central nervous system toxic effects. Magnetic resonance imaging with gadolinium contrast medium administration provides an important methodological advantage over previously described techniques and is a safe, reproducible, and superior method of orbital imaging.

Optical tracking of contrast medium bolus to optimize bolus shape and timing in dynamic computed tomography

One of the biggest challenges in dynamic contrast-enhanced CT is the optimal synchronization of scan start and duration with contrast medium administration in order to optimize image contrast and to reduce the amount of contrast medium. We present a new optically based approach, which was developed to investigate and optimize bolus timing and shape. The time-concentration curve of an intravenously injected test bolus of a dye is measured in peripheral vessels with an optical sensor prior to the diagnostic CT scan. The curves can be used to assess bolus shapes as a function of injection protocols and to determine contrast medium arrival times. Preliminary results for phantom and animal experiments showed the expected linear behavior between dye concentration and absorption. The kinetics of the dye was compared to iodinated contrast medium and was found to be in good agreement. The contrast enhancement curves were reliably detected in three mice with individual bolus shapes and delay times of 2.1, 3.5 and 6.1 s, respectively. The optical sensor appears to be a promising approach to optimize injection protocols and contrast enhancement timing and is applicable to all modalities without implying any additional radiation dose. Clinical tests are still necessary.

Adjunctive ultrasonography during carotid artery stenting to minimize iodine contrast use

Carotid artery stenting (CAS) in patients with chronic kidney disease carries a significant risk of contrast-induced nephropathy. We report a case of CAS with adjunctive sonography to reduce the amount of contrast medium during angiography. A 71-year-old man presented with a symptomatic right carotid stenosis. He was selected for CAS due to significant medical comorbidity, which included severe renal impairment. A preoperative noncontrast CT was performed to assess anatomical suitability and to plan arch vessel cannulation. We undertook CAS with the use of intraoperative ultrasound. Sonography was used to monitor the manipulation of wires, catheters, and stents. Four milliliters of contrast was required to complete the procedure successfully with no deterioration in postoperative renal function. Adjunctive ultrasound is feasible to reduce contrast use in patients with severe renal impairment undergoing CAS.

AS-189: Percutaneous Coronary Intervention for Chronic Total Occlusion in Patients with Chronic Renal Insufficiency

Patients with chronic total occlusive (CTO) have higher prevalence of diabetes and chronic renal insufficiency (CRI) and further, CTO intervention is definitely higher chance to use larger amount of contrast media due to longer procedure time. Thus, CTO intervention objectively can be more frequently associated acute exacerbation of CRI or new onset acute renal insufficiency. There have been limited data regarding the impact of chronic renal insufficiency on major angiographic and clinical outcomes following percutaneous coronary intervention (PCI) with drug-eluting stents (DES) for CTO lesions.

Protective Embolization of the Gastroduodenal Artery with a One-HydroCoil Technique in Radioembolization Procedures

Protective occlusion of the gastroduodenal artery (GDA) is required to avoid severe adverse effects and complications in radioembolization procedures. Because of the expandable features of HydroCoils, our goal was to occlude the GDA with only one HydroCoil to provide particle reflux protection. Twenty-three subjects with unresectable liver tumors, who were scheduled for protective occlusion of the GDA before radioembolization therapy, were included. The primary end point was to achieve a proximal occlusion of the GDA with only one detachable HydroCoil. Evaluated parameters were duration of deployment, and early (during the intervention) and late (7-21days) occlusion rates of GDA. Secondary end points included complete duration of the intervention, amount of contrast medium used, fluoroscopy rates, and adverse effects. In all cases, the GDA was successfully occluded with only one HydroCoil. The selected diameter/length range was 4/10mm in 2 patients, 4/15mm in 6 patients, and 4/20mm in 15 patients. HydroCoils were implanted, on average, 3.75mm from the origin of the GDA (range 1.5-6.8mm), with an average deployment time of 2:47 (median 2:42, range 2:30-3:07) min. In 21 (91%) of 23 patients, a complete occlusion of the GDA was achieved during the first 30min after the coil implantation; however, in all patients, a late occlusion of the GDA was present after 6 to 29days. No clinical or technical complications were reported. We demonstrated that occlusion of the GDA with a single HydroCoil is a safe procedure and successfully prevents extrahepatic embolization before radioembolization.

CORONARY CT ANGIOGRAPHY USING ULTRA-LOW DOSE CONTRAST MEDIA: RADIATION DOSE AND IMAGE QUALITY

The radiation dose and the amount of contrast media are the limitation of coronary CT angiography (CTCA). Low dose protocol of contrast media using 80kV has not been elucidated. We compared the radiation dose and image quality of the ultra-low dose protocol using 80kV and standard protocol using

Comparison of the surgical and transcatheter aortic valve replacement in high-risk patients

Introduction: Transcatheter aortic valve implantation (TAVI) has evolved as an alternative method for surgical valve replacement in high-risk patients. Initially the transfemoral (TF) approach was used, later the transapical (TA) approach was adopted as an option for selected patients. The aim of our study was to compare the safety and anatomical and functional success of TAVI procedures with surgical aortic valve replacement (SAVR).Material and methods: The study included 45 consecutive high-risk patients with symptomatic severe aortic stenosis indicated for aortic valve intervention who met the entry criteria (age >75 years; logistic Euroscore >15%). The patients were allocated to one of three groups according the type of procedure: SAVR (n=15), TAVI TA (n=15) and TAVI TF (n=15). The groups did not differ in their preoperative characteristics except for myocardial infarction, which was more common in the TAVI groups. The Edwards Sapien valve was implanted in the TAVI patients and Edwards Perimount bioprosthesis was used in the SAVR patients. The TA approach was used in patients who were not eligible for the TF approach.Results: All procedures were technically successful. The prostheses used in the SAVR group were smaller in size than those implanted in the TA and TF groups (SAVR, 22.2(21.7;22.8); TA, 24.0(23.6;24.3); TF, 25.0(24.6;25.3)). The TA group patients were exposed to radiation for a shorter period and received a larger amount of contrast medium (TA, 9.7(9.0;10.5)min and 278.3(238.5;318.1)ml; TF, (15.0(13.7;16.4)min, 200.7(179.2;222.1)ml) in TF group). There were no statistically significant differences in the duration of procedures, stay in the intensive care unit and in the hospital, and intra- and post-operative complications among the groups. Early mortality (30 days) was 2.2%. One patient died of clostridium sepsis on day 12 (early mortality, 2.2%). Another patient died due to the multi-organ failure on the 58th day of hospital stay. Five other patients died during one-year follow-up (one-year survival rate, 86.3%). The functional class highly improved in all the patients, of whom 80% were with NYHA classes I or II.Conclusion: Our results show that TAVI is a safe method for treatment of aortic stenosis in high-risk patients and its early results are comparable with surgical aortic valve replacement. The TF and TA approaches are equally efficient, with similar outcomes and complication rates. Provided these results are confirmed at long-term follow-up, it can be assumed that the indication criteria for TAVI approaches will expand.

Type IB and type III endoleak 8 years after endovascular aneurysm repair

An 86-year-old man was admitted to our hospital for abdominal pain and underwent an AneurRx bifurcated endograft (Medtronic AVE, Sunnyvale, Calif) implantation 8 years earlier for a 7-cm-diameter abdominal aortic aneurysm (AAA). His comorbidities were chronic atrial fibrillation, diabetes, dyslipidemia, chronic renal failure, hypertension, severe chronic obstructive pulmonary disease, and coronary artery disease. This patient also underwent an appendicectomy, inguinal hernioplasty, and cholecystectomy. An expandible abdominal mass was found during a clinical examination. Doppler ultrasound imaging and a computed tomography scan showed a severe increase of AAA diameter to 11 cm, associated with a type IB endoleak from the right leg displaced into the aneurysmal sac itself and to a type III endoleak due to detachment of the contralateral leg (A-C). Similar patients reported in the literature underwent open or endovascular treatment. Our patient was assessed by the anesthesiologist and cardiologist as being in American Society of Anesthesiologist class IV and therefore unfit for surgical repair, so an endovascular approach was planned. Through a left transaxillary access, a hydrophilic guidewire was introduced first into the endograft main body and its right leg and, thereafter, was captured by means of an Amplatz GooseNeck (EV3, Plymouth, Minn) introduced through the right common femoral artery. This was exchanged with a stiff guidewire, and a right aorto-uni-iliac Zenith Cook endograft (Cook Inc, Bloomington, Ind) was deployed. After surgical exposure of the left common femoral artery, an endovascular plug (Iliac Plug Cook Zip-20) was inserted in the ipsilateral common iliac artery. A femoro-femoral crossover bypass was completed with a 7-mm external-supported polytetrafluoroethylene graft (Vascutek Ltd, Inchinnan, Scotland). The procedure was performed with spinal anesthesia, the operating time was 135 minutes, and the contrast medium amount was 250 mL. The patient’s postoperative period was uneventful and he was discharged after 8 days, with no worsening of renal condition. A computed tomography scan at 6 months showed a good result of the procedure, with no endoleak and reduction of the AAA diameter (D).

Simultaneous bilateral contrast injection in computed tomography pulmonary angiography

Computed tomography pulmonary angiography (CTPA) has evolved as the gold standard for diagnosing pulmonary embolism. However, subsegmental arteries are often not assessed to do insufficient attenuation. To evaluate the influence of simultaneous bilateral versus unilateral injection of a fixed amount of contrast media on pulmonary artery opacification and image quality in CTPA. In this institutional review board-approved prospective study, 180 patients (91 women, mean age 61.9 ± 16.5 years) referred for CTPA (100 kV) due to suspected pulmonary embolism were randomized in groups of 45 patients each, with either unilateral (A:4 mL/s; B:6 mL/s) or bilateral (C: 6 mL/s; D: 8 mL/s) (Y-shaped line) injection of 50 mL contrast media. Attenuation was assessed including the subsegmental arteries (4th order). Image quality was evaluated by two readers in consensus using a three-point grading scale (3 = excellent image quality, no artifacts, 1 = non-diagnostic). Mean pulmonary artery attenuation was significantly higher with bilateral injection (1st to 3rd order: A: 303.6 ± 8.8HU; B: 371.1 ± 11.0HU vs. C: 443.2 ± 24.1HU; D: 562.3 ± 15.3HU, P < 0.001). Evaluation of subsegmental arteries was feasible for all patients in groups B-D, but only in 36/45 (80%) patients in group A. Subsegmental attenuation was significantly higher with bilateral injection (A: 284.7 ± 12.1HU; B: 367.4 ± 12.1HU vs. C: 494.2 ± 21.5HU; D: 562.3 ± 26.7HU, P < 0.001). Image quality was diagnostic for all patients but best for group C (A: 2.15 ± 0.4; B: 2.14 ± 0.5; C: 2.92 ± 0.3, and D: 2.51 ± 0.5). Using the same amount of contrast media, bilateral injection yields higher pulmonary artery attenuation and better image quality than unilateral injection. This technique may improve subsegmental pulmonary artery assessment.

In vitro three‐dimensional aortic vasculature modeling based on sensor fusion between intravascular ultrasound and magnetic tracker

It is desirable to reduce aortic stent graft installation time and the amount of contrast media used for this process. Guidance with augmented reality can achieve this by facilitating alignment of the stent graft with the renal and mesenteric arteries. For this purpose, a sensor fusion is proposed between intravascular ultrasound (IVUS) and magnetic trackers to construct three-dimensional virtual reality models of the blood vessels, as well as improvements to the gradient vector flow snake for boundary detection in ultrasound images. In vitro vasculature imaging experiments were done with hybrid probe and silicone models of the vasculature. The dispersion of samples for the magnetic tracker in the hybrid probe increased less than 1 mm when the IVUS was activated. Three-dimensional models of the descending thoracic aorta, with cross-section radius average error of 0.94 mm, were built from the data fusion. The development of this technology will enable reduction in the amount of contrast media required for in vivo and real-time three-dimensional blood vessel imaging.

Coronary Angiography with Gadolinium in Patients with Severe Allergy to Iodinated Contrast Media

The use of iodinated contrast media is contraindicated in some patients due to serious life-threatening adverse events. In such cases, there are reports that gadolinium (gadobutrol), which is commonly employed in magnetic resonance imaging, may be used as contrast media for coronary angiography. We report two cases with a history of severe allergy to iodinated contrast agent who underwent coronary angiography with gadolinium. The procedures were well tolerated, the amount of contrast media did not exceed 0.3-0.4 ml/kg and the images obtained were of acceptable quality for diagnostic purposes. Cinecoronariografia com Gadolínio em Pacientes com Alergia Grave ao Contraste Iodado Em alguns pacientes a utilização dos meios de contraste iodados é contraindicada pela possibilidade de desencadearem efeitos colaterais graves ameaçadores da vida. Nesses casos, existem relatos em que o gadolínio (gadobutrol), comumente empregado na ressonância nuclear magnética, pode ser usado como meio de contraste para coronariografia. Relatamos dois casos com antecedente de alergia grave ao contraste iodado, que realizaram coronariografia com gadolínio. Os procedimentos foram bem tolerados, a quantidade de contraste não excedeu 0,30,4 ml/kg e as imagens obtidas foram de qualidade aceitável para efeitos de diagnóstico.

Cinecoronariografia com gadolínio em pacientes com alergia grave ao contraste iodado

Em alguns pacientes a utilização dos meios de contraste iodados é contraindicada pela possibilidade de desencadearem efeitos colaterais graves ameaçadores da vida. Nesses casos, existem relatos em que o gadolínio (gadobutrol), comumente empregado na ressonância nuclear magnética, pode ser usado como meio de contraste para coronariografia. Relatamos dois casos com antecedente de alergia grave ao contraste iodado, que realizaram coronariografia com gadolínio. Os procedimentos foram bem tolerados, a quantidade de contraste não excedeu 0,3-0,4 ml/kg e as imagens obtidas foram de qualidade aceitável para efeitos de diagnóstico.

Incorporation of a Balloon-Cushion Stenting Technique into the Culotte Stenting Technique in Left Main Coronary Artery Bifurcation Interventions

Background: Percutaneous coronary intervention (PCI) for a left main coronary artery (LMCA) with its distal bifurcation lesions remains a challenge. Acute sidebranch occlusion after main branch stenting can potentially lead to catastrophic events. Here we describe a novel balloon-cushion stenting technique to be incorporated into the culotte stenting technique for true LMCA bifurcation lesions to prevent acute sidebranch occlusion. Methods and Results: 1) Predilatation with 2 balloons with kissing for better sidebranch preparation. 2) Balloonstent simultaneous kissing inflation, with a stent in the dominant artery and a 1.5/20 mm balloon from LMCA to the sidebranch. 3) After the stent deployment, a Crusade microcatheter was introduced via wire in the dominant vessel for wire re-crossing of the stent strut. The standard culotte technique and final kissing balloon inflation were then performed. Twelve patients were treated with this balloon-cushion stenting technique (Group A) and 18 patients with the conventional double-stent techniques (Group B). One case of acute sidebranch occlusion occurred in Group B. The amount of contrast medium and procedural time did not differ statistically between the 2 groups. Conclusions: The present study suggests that incorporation of the balloon-cushion stenting technique into the culotte stenting technique for LMCA bifurcation intervention is feasible and effective in avoiding acute sidebranch occlusion.

Increased Plasma Osmolar Gap Is Predictive of Contrast-Induced Acute Kidney Injury

Contrast-induced acute kidney injury (CIAKI) is a common complication after percutaneous coronary artery intervention (PCI). It is urgent to find a novel, easily measurable and accurate predictor for the early detection of CIAKI. Hyperosmolarity and large amounts of contrast media are risk factors for CIAKI. However, there is no study on plasma osmolar gap as a predictor of CIAKI. We enrolled 89 patients undergoing elective PCI and tested changes of serum sodium, osmolar gap, and renal function at 0, 6, 12 and 24 hours. Plasma osmolar gap was calculated using the following formula: measured plasma osmolarity - [2(Na) + serum urea nitrogen/2.8 + glucose/18]. CIAKI was defined as follows: increase in serum creatinine of ≥ 50%, increase in serum creatinine of ≥ 0.3 mg/dL, or decrease in estimated glomerular filtration rate of ≥ 25% within 24 hours after PCI. The incidence of CIAKI was 13.5% (12/89 patients). The CIAKI group had higher plasma osmolar gaps 6 hours after PCI. The adjusted hazard ratio of the plasma osmolar gap from hour 6 (1-mOsm/L increments) to the development of CIAKI was 1.12 (95% confidence interval [CI], 1.01-1.26; P = 0.041). Sensitivity and specificity of 7 mOsm/L or higher plasma osmolar gap at hour 6 were 70.0% and 76.6%, respectively (area under the ROC curve = 0.77 [95% CI, 0.65-0.89]). Increased plasma osmolar gap may precede the development of CIAKI in patients undergoing PCI. In conclusion, plasma osmolar gap may be a useful predictor for the development of CIAKI.

Comparison of Contrast Media and Low-Molecular-Weight Dextran for Frequency-Domain Optical Coherence Tomography

Although an intracoronary frequency-domain optical coherence tomography (FD-OCT) system overcomes several limitations of the time-domain OCT (TD-OCT) system, the former requires injection of contrast media for image acquisition. The increased total amount of contrast media for FD-OCT image acquisition may lead to the impairment of renal function. The safety and usefulness of the non-occlusion method with low-molecular-weight dextran L (LMD-L) via a guiding catheter for TD-OCT image acquisition have been reported previously. The aim of the present study was to compare the image quality and quantitative measurements between contrast media and LMD-L for FD-OCT image acquisition in coronary stented lesions. Twenty-two patients with 25 coronary stented lesions were enrolled in this study. FD-OCT was performed with the continuous-flushing method via a guiding catheter. Both contrast media and LMD-L were infused at a rate of 4 ml/s by an autoinjector. With regard to image quality, the prevalence of clear image segments was comparable between contrast media and LMD-L (97.9% vs. 96.5%, P=0.90). Furthermore, excellent correlations were observed between both flushing solutions in terms of minimum lumen area, mean lumen area, and mean stent area. The total volumes of contrast media and of LMD-L needed for OCT image acquisition were similar. FD-OCT image acquisition with LMD-L has the potential to reduce the total amount of contrast media without loss of image quality.

Renal impairment and transapical aortic valve implantation: impact of contrast medium dose on kidney function and survival

Patients undergoing transapical aortic valve implantation (TA-AVI) are usually over 80 years old and have a high prevalence of chronic kidney disease. However, transcatheter valve therapies require the use of contrast injections with the risk of nephrotoxicity. The aim of this study was to evaluate post-operative kidney function and survival in patients with pre-existing renal impairment with regard to the amount of contrast media used during TA-AVI. From January 2008 to March 2011, 50 patients (52% females, mean age 80.7 ± 5.3 years) with a serum creatinine level of >1.3 mg/dl were investigated. Patients receiving a dose of <100 ml of a contrast agent (low-dose group, n = 24) were separated from those who received >100 ml of a contrast agent (high-dose group, n = 26). An acute contrast-induced nephropathy (CIN) was defined as a serum creatinine increase of 0.5 mg/dl or by >25% of a baseline value within 48 h from contrast medium administration. Patients in both groups had similar characteristics in terms of age, sex, body mass index and comorbidities. The median pre-contrast creatinine was 1.67 (1.37-1.83) mg/dl in the low-dose group and 1.51 (1.26-1.98) mg/dl in the high-dose group (P = 0.76). The post-contrast creatinine at 48 h was 1.53 (1.33-2.05) and 2.29 (1.67-2.86) mg/dl in the groups receiving low- and high-dose contrast agents, respectively (P = 0.007). CIN occurred in 41.7% (n = 10) of patients in the low-dose contrast group and in 69.2% (n = 18) in the high-dose contrast group (P = 0.046). Haemodialysis is necessary for 16.7% of the low-dose group and 38.5% of the high-dose group (P = 0.12). Trends towards longer intensive care unit and hospital stay were seen in patients with an extensive use of contrast media [4.3 (2.5-6.5) vs. 5 (3-7.8) days and 12 (9-14.3) vs. 13 (9-18) days, P = 0.091 vs. P = 0.546, respectively]. Regarding death, 3-month and 3-year mortality were significantly higher in the high-dose group (8.3 vs. 30.8%, P = 0.036 and 25 vs. 61.5%, P = 0.004, respectively). Our results indicate a possible association between higher CIN and mortality rate and the extensive use of contrast media during TA-AVI among high-risk patients with pre-existing renal impairment.