Comparison of diagnostic and therapeutic value of transesophageal echocardiography, intravascular ultrasonic imaging, and intraluminal phased-array imaging in aortic dissection with tear in the descending thoracic aorta (type B)

Transesophageal echocardiography (TEE) and conventional intravascular ultrasound (IVUS) have limited capabilities in type B aortic dissection. To evaluate its diagnostic value, intraluminal phased-array imaging (IPAI) was compared with IVUS and TEE. In 23 patients with type B aortic dissection, IPAI was tested with respect to its ability to depict true lumen (TL) and false lumen (FL), to localize which abdominal arteries originate from the TL and FL, and to identify all entries and reentries. After the completion of TEE, 2 additional examiners performed angiography and positioned an AcuNav catheter inside the TL. An IVUS catheter was then introduced into the TL by a fourth examiner. All examiners were blinded to one another. Four additional patients with type B aortic dissection developed peripheral malperfusion due to TL collapse. Transvenous IPAI was used to guide emergency fenestration of the intimal flap. TL and FL could be equally well identified by all diagnostic methods. IPAI detected more entries than IVUS (3.0 +/- 1.2 vs 0.8 +/- 0.5, p <0.001), and thoracic IPAI depicted more entries than TEE (1.8 +/- 1.0 vs 1.2 +/- 0.5, p <0.001). IPAI and IVUS showed >90% of the abdominal side branches. In all patients with peripheral malperfusion, successful emergency intimal flap fenestration was safely guided by IPAI. In conclusion, in the detailed diagnostic evaluation of type B aortic dissection, IPAI is superior to IVUS and TEE in detecting communications between the TL and FL. IPAI is also highly useful as a guiding tool for emergency intimal flap fenestration.     

Subintimal angioplasty of an aortoiliac occlusion: re-entry site created using a transseptal needle under intravascular ultrasound guidance.

PURPOSE: To report the use of a transseptal needle to cross the intimal flap in subintimal angioplasty of a flush aortoiliac occlusion via a retrograde approach. CASE REPORT: A 53-year-old man with claudication of the right lower limb and an angiographically documented right aortoiliac occlusion was treated with subintimal angioplasty via an ipsilateral retrograde approach. After puncture of the right common femoral artery, a 0.035-inch hydrophilic guidewire was advanced via the subintimal space toward the aortic true lumen, but the wire could not re-enter the true lumen. A transseptal needle was used to puncture the intimal flap under intravascular ultrasound (IVUS) guidance. Angioplasty/stenting was performed successfully, and the patient's symptoms were relieved. Computed tomography at 15 months revealed patent stents. CONCLUSION: The use of a transseptal needle to cross the intimal flap in total aortoiliac occlusions is technically feasible under IVUS guidance and enables successful angioplasty.     

Successful stent implantation guided by intravascular ultrasound and a Doppler guidewire without contrast injection in a patient with allergy to iodinated contrast media

Presence of allergy to iodinated contrast may prevent percutaneous coronary intervention (PCI) to be performed. We present a 76-year-old male with a history of allergic reaction to iodinated contrast who successfully underwent intravascular ultrasound (IVUS) and a Doppler guidewire-guided PCI. Stent size was determined based on IVUS. After PCI, stent expansion and a lack of edge dissection or incomplete apposition were confirmed by IVUS and a good antegrade coronary flow was confirmed by a Doppler guidewire. Thus, PCI without contrast injection under IVUS and a Doppler guidewire-guidance may be feasible in selected patients with allergy to iodinated contrast.     

In vivo antegrade fenestration of abdominal aortic stent-grafts.

PURPOSE: To examine in a canine model the feasibility of antegrade fenestration of abdominal aortic stent-grafts to preserve the patency of the renal arteries. METHODS: Two large dogs underwent antegrade fenestration of stent-grafts in the perirenal aorta. Before fenestration, bare stents were inserted in both renal arteries as fluoroscopic landmarks. A 12-mm iliac extension served as the canine aortic endograft. The first procedure was done under ultrasound and fluoroscopic guidance, using an intravascular ultrasound (IVUS) probe inserted in the vena cava and a Pioneer IVUS catheter. The second was performed exclusively under fluoroscopic guidance with a Brockenbrough needle. Angiograms and duplex ultrasound were planned for 1 month, after which the dogs would be sacrificed for autopsy. The explanted endograft was subjected to biomaterials analysis, with a focus on fabric tear. RESULTS: Perforation of the aortic graft and catheterization of the renal arteries with a floppy guidewire were possible in both animals. In dog 1, aortic graft dilation and subsequent fenestration were not possible, and the experiment was terminated. However, the procedure was successful in both renal arteries of dog 2. At 1-month follow-up in this dog, both renal arteries were patent. Stent fractures were observed bilaterally. There was no extension of the damage to the fabric beyond the area of fenestration. CONCLUSION: In vivo antegrade fenestration of aortic endografts is technically feasible. However, improvements in technique, instrumentation, and materials are required to make it a reliable and reproducible way of allowing stent-graft vascularization of aortic side branches.     

Ultrasound navigation through the heart for off-pump aortic valved stent implantation: new tools for new goals.

PURPOSE: To validate the use of simultaneous intracardiac and intravascular ultrasound (IVUS) guidance for periprocedural dimension assessment, Residual-Coronary/Sinus-Stent Index (RCSSI) estimation, target site identification, deployment monitoring, and quality control of off-pump aortic Valved Stent implantation. METHODS: Five pigs (56+/-5 kg) underwent off-pump orthotopic aortic valve implantation using a custom-made self-expanding Valved Stent. Intracardiac ultrasound (AcuNav) was introduced via the right femoral vein. After left-sided thoracotomy, pursestring sutures were placed on the left ventricular apex. Following heparinization, a guidewire was inserted through the apex and advanced over the aortic valve under fluoroscopy. A wire-guided IVUS catheter transducer (6-F, 12.5-MHz) was inserted and the aortic target site identified. IVUS probe location was tracked with AcuNav, and measures of the aortic root were taken by both. After removal of the IVUS, the Valved Stent delivery system was introduced over the guidewire under fluoroscopy and AcuNav monitoring; the Valved Stent was deployed over the native valves. In vivo assessment included leaflet motion, planimetric valve orifice and RCSSI (stent to aortic wall distance/coronary diameter) calculations, coronary blood flow characteristics, transvalvular gradient, regurgitation, and paravalvular leaking in combination with continuous cardiac output measures. Macroscopic analysis was performed at necropsy. RESULTS: IVUS dimensions of the aortic root were equal to AcuNav and necropsy dimensions. Both tools showed good valvular function, with full valvular opening and closing in 3 of 5 valves. At necropsy, the 3 aortic Valved Stents were safely anchored. One Valved Stent was placed supra-annularly; 2 dislodged into the left ventricle because of size mismatch. One Valved Stent showed a moderate to severe paravalvular leak. CONCLUSIONS: Simultaneous intracardiac and intravascular ultrasound-guided off-pump orthotopic aortic Valved Stent implantation via left sided thoracotomy is feasible in an animal model. IVUS and intracardiac ultrasound allow adequate aortic dimension assessment and Valved Stent delivery monitoring, as well as postimplantation coronary flow evaluation.     

Novel intravascular ultrasound-guided method to create transintimal arterial communications: initial experience in peripheral occlusive disease and aortic dissection.

PURPOSE: To report our experience using a commercially available catheter-based system equipped with an intravascular ultrasound (IVUS) transducer to achieve controlled true lumen re-entry in patients undergoing subintimal angioplasty for chronic total occlusions (CTO) or aortic dissections. METHODS: During an 8-month period, 10 patients (6 men; mean age 73.4 years) with lower extremity (LE) ischemia from CTOs (n=7) or true lumen collapse from aortic dissections (n=3) were treated. Subintimal access and controlled re-entry of the CTOs were performed with a commercially available 6.2-F dual-lumen catheter, which contained an integrated 64-element phased-array IVUS transducer and a deployable 24-G needle through which a guidewire was passed once the target lumen was reached. The occluded segments were balloon dilated; self-expanding nitinol stents were deployed. In the aortic dissections, fenestrations were performed using the same device, with the IVUS unit acting as the guide. The fenestrations were balloon dilated and stented to support the true lumen. RESULTS: Time to effective re-entry ranged from 6 to 10 minutes (mean 7) in the CTOs; antegrade flow was restored in all 7 CTOs, and the patients were free of ischemic symptoms at up to 8-month follow-up. In the aortic dissection cases, the fenestrations equalized pressures between the lumens and restored flow into the compromised vessels. There were no complications related to the use of this device in any of the 10 patients. CONCLUSIONS: Our preliminary results demonstrate the feasibility of using this catheter-based system for subintimal recanalization with controlled re-entry in CTOs and for aortic flap fenestrations in aortic dissections. This approach can improve the technical success rate, reduce the time of the procedure, and minimize potential complications.     

Novel technique using intravascular ultrasound-guided guidewire cross in coronary intervention for uncrossable chronic total occlusions.

The experience of using a novel application of intravascular ultrasound (IVUS)-guided percutaneous coronary interventions for chronic total occlusions is reported in 2 cases. In the first case, an IVUS catheter was advanced into a side branch to identify the entry point of the major branch. In the second case, IVUS-guided penetration of the guidewire from the false lumen to the true lumen after causing a dissection was successful.     

The principles of ultra-low contrast percutaneous coronary intervention

Ultra-low contrast percutaneous coronary intervention (ULCPCI) can be performed electively in advanced chronic kidney disease. Engage guide catheter and advance guidewire into the coronary artery without using contrast. IVUS-guided PCI can reduce the contrast load. Perform co-registration of distal and proximal radio-opaque marker bands of intravascular ultrasound (IVUS) catheter. Deploy the stent at the target lesion under fluoroscopic guidance of these co-registered position of the IVUS-marking images. Complete the ULCPCI procedure with a final angiography using minimal contrast. Newer contrast sparing techniques and intravascular imaging technologies provide opportunities to perform ULCPCI efficiently with good results and the least complications.     

Successful fenestration using a chronic total occlusion-dedicated guidewire in a patient with catheter-induced dissection of the right coronary artery

Guiding catheter-induced coronary artery dissection is a rare, but hazardous complication of percutaneous coronary intervention (PCI) and is associated with the potential risk of impairment of coronary blood flow. Therefore, occurrence of this complication mandates a prompt revascularization procedure. A 68-year-old female patient with acute myocardial infarction caused by total occlusion of the proximal right coronary artery (RCA) underwent PCI. After revascularization by thrombus aspiration, catheter-induced dissection of the ostium of the right coronary artery (RCA) occurred when the guiding catheter and guidewire were accidentally removed. An attempt to engage the guiding catheter and guidewire into the true lumen failed because of total occlusion of the right coronary ostium. A chronic total occlusion (CTO)-dedicated guidewire was then used to create a fenestration of the intimal flap, and after it penetrated into the distal true lumen, a low-profile balloon catheter was dilated, and coronary flow from the false to the true lumen was established. After balloon dilatation, stents were deployed at both the dissection site and in the distal lesion. The final angiogram revealed restoration of coronary blood flow. We propose that application of a CTO-dedicated guidewire to create a fenestration of the intimal flap in the region of the coronary dissection is a feasible and effective alternative to conventional procedures.     

Intravascular ultrasound in patients with suspected aortic dissection: comparison with transesophageal echocardiography]

Thirteen patients with suspected aortic dissection (two women, 11 men, age 61 +/- 10.8 years) underwent transesophageal echocardiography (TEE), intravascular ultrasound (IVUS), angiography, and in part computed tomography (CT). TEE was performed using 3.5 or 3.75 MHz ultrasound transducers. IVUS examination was done using a 6F 20 MHz "rotational-tip" IVUS catheter (Boston Scientific) advanced over a guiding-wire positioned in the ascending aorta by the "side-saddle" technique. In two patients it was not possible to advance the catheter into the abdominal aorta. Of the remaining 11 patients, eight had aortic dissection (six Typ III, one Typ II, and one Typ I, de Bakey classification). Two patients had aortic aneurysms without dissection and one patient had a perforation of the ascending aorta. TEE, CT, and angiography led to the correct diagnosis in all patients, while IVUS failed to provide precise information within the ascending aorta and the aortic arch. Reasons were the limited scanfield of the 20 MHz transducer and the inability to steer and position the IVUS catheter. Contrary to the limited value in the ascending aorta, IVUS could successfully scan the entire descending aorta, including the dissection membrane and the originating vessels, if the max. diameter was less than 4 cm. No adverse effects occurred. Intravascular ultrasound allows to scan the entire aorta in patients with suspected aortic dissection. The current limitations can be solved only by the introduction of steerable and/or low frequency catheters.     

Invasive human magnetic resonance imaging: feasibility during revascularization in a combined XMR suite.

We tested the feasibility and safety of invasive magnetic resonance imaging (MRI) during peripheral angioplasty. Real-time MRI can image soft tissue and may potentially guide therapeutic procedures without ionizing radiation or nephrotoxic contrast. MRI-guided diagnostic catheterization has been described recently, but safe and conspicuous catheter devices are not widely available. An active guidewire, which serves as an MRI receiver antenna, might be useful to guide catheterization or even to image atheroma. We describe a combined interventional suite offering both X-ray fluoroscopy and real-time MRI. We used a 0.030' active guidewire receiver coil for invasive MRI after X-ray lesion traversal in patients undergoing percutaneous iliofemoral artery revascularization. Intravascular MRI was compared with noninvasive MRI, X-ray angiography, and intravascular ultrasound (IVUS). Seven eligible patients consented to participate, but three were excluded because of lengthy revascularization procedures. Four remaining patients safely underwent combined X-ray fluoroscopy and real-time magnetic resonance imaging (XMR) transport, continuous monitoring, and all imaging modalities. There was no device dislodgment, contamination or evidence of heating. The intravascular MRI coil was well visualized except at the tip, but did not provide superior mural imaging compared with IVUS. Therefore, because an adequate safety and workflow experience was obtained, enrollment was terminated after only four subjects. Invasive MRI is feasible and apparently safe during peripheral angioplasty. Patients can safely be transported and monitored in an XMR interventional suite. An active quarter-wavelength guidewire coil does not provide superior imaging compared with IVUS, but provides satisfactory guidewire visualization. These tools may prove useful for advanced therapeutic procedures in the future.     

Interventional Management of Aortic Dissection

BACKGROUND: Modern high-resolution imaging techniques have provided new insights into the pathogenesis of aortic dissection during recent years. Distinct pathologic entities or potential precursors of classic false-lumen aortic dissection such as intramural hematoma or penetrating atherosclerotic ulcer have been identified. As a result, a novel classification according to Svensson used in addition to the standard differentiation according to DeBakey or Stanford has been introduced. Due to improved diagnostic imaging, preoperative mortality has decreased but mortality remains substantial (up to 1.4% per hour within the first 2 days) related to complications of aortic dissection such as aortic rupture, bleeding, pericardial tamponade, critical branch vessel ischemia, multiorgan failure, and myocardial infarction. EXAMINATIONS: Transesophageal echocardiography, angiography, magnetic resonance imaging or computed tomography as well as intravascular ultrasound are used for a complete vascular "staging" of patients with aortic dissection after initial stabilization (with or without surgery).New catheter-based interventional techniques have been developed to improve the poor prognosis of aortic dissection: 1 Percutaneous balloon fenestration (PTF) of the intimal flap improves perfusion in case of bowel, limb, or renal ischemia. 2. Aortic stent-graft placement allows for occlusion of the intimal entry tear by implantation of a membrane-covered, self-expanding stent-graft to initiate progressive thrombus formation within the false lumen. Compared to the traditional surgical approaches, both techniques have a low complication rate. The development of these techniques may help to further improve to decrease patients' morbidity and mortality.     

ViewIT improves intravascular ultrasound‐guided wiring in coronary intervention of chronic total occlusion

Terumo intravascular ultrasound (IVUS) ViewIT facilitates IVUS‐guided wiring in percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) due to its low profile and surface coating. In PCI for CTO, the first guidewire is sometimes inserted into the subintimal space, and observation by IVUS through the first guidewire in the subintima can allow the second guidewire to be led visually into the true lumen. We describe a case of CTO in which ViewIT was inserted into the subintimal space of the CTO lesion and scanning from the coronary ostium to the CTO subintimal space allowed the second guidewire to be led into the true lumen. © 2010 Wiley‐Liss, Inc.     

Percutaneous fenestration of dissecting intima with a transseptal needle. A new therapeutic technique for visceral ischemia complicating acute aortic dissection.

Noncardiac visceral ischemia is a major complication with acute aortic dissection and is caused by obstruction of the major visceral arteries by dissecting intima. Two patients with this condition underwent emergency percutaneous fenestration of dissecting intima, and the blood flow to the lower extremity and kidney was restored. A transseptal needle and peripheral angioplasty balloon catheter were used for fenestration. There were no associated complications in either patient. One patient was treated medically and another had ascending aortic replacement surgery the day after percutaneous fenestration. Clinical follow-up of 10 and 5 months, respectively, revealed good clinical outcomes. Percutaneous fenestration should be considered the treatment of choice for visceral ischemia due to acute aortic dissection.     

Percutaneous fenestration of dissecting intima with a transseptal needle. A new therapeutic technique for visceral ischemia complicating acute aortic dissection

Noncardiac visceral ischemia is a major complication with acute aortic dissection and is caused by obstruction of the major visceral arteries by dissecting intima. Two patients with this condition underwent emergency percutaneous fenestration of dissecting intima, and the blood flow to the lower extremity and kidney was restored. A transseptal needle and peripheral angioplasty balloon catheter were used for fenestration. There were no associated complications in either patient. One patient was treated medically and another had ascending aortic replacement surgery the day after percutaneous fenestration. Clinical follow-up of 10 and 5 months, respectively, revealed good clinical outcomes. Percutaneous fenestration should be considered the treatment of choice for visceral ischemia due to acute aortic dissection. © 1992 Wiley-Liss, Inc.     

主动脉夹层动脉瘤的外科治疗

目的 :总结 1992年 6月至 2 0 0 2年 6月对 2 5例主动脉夹层动脉瘤病人的外科治疗经验。方法 :采用Cabrol手术 10例 ,Bentall手术 7例 ,升主动脉与腹主动脉搭桥转流手术 6例 ,升主动脉与双髂总动脉搭桥转流结合动脉内膜开窗手术 1例 ,升主动脉夹层缝闭加主动脉瓣成形术 1例。结果 :2 4例生存 ,1例Bentall手术左冠状动脉吻合口出血而死亡。结论 :主动脉夹层病人 ,手术中当冠状动脉开口直接缝合于人工血管有困难时 ,采用Cabrol手术 ,使吻合口无张力而且对合严密 ,避免了冠状动脉开口周围内膜撕脱和吻合口漏血。对于DeBakeyⅢ型的病人 ,采用升主动脉与腹主动脉或双髂总动脉搭桥转流术结合动脉内膜开窗术 ,治疗效果满意。对于手术中无法止血的主动脉漏血和左心室漏血 ,采用瘤袋或自体心包包裹漏血区 ,然后与右心房进行搭桥吻合 ,将漏血引入右心房而达到止血目的。     

Outcome from balloon induced coronary artery dissection after intracoronary beta radiation

OBJECTIVE: To evaluate the healing of balloon induced coronary artery dissection in individuals who have received beta radiation treatment and to propose a new intravascular ultrasound (IVUS) dissection score to facilitate the comparison of dissection through time. DESIGN: Retrospective study. SETTING: Tertiary referral centre. PATIENTS: 31 patients with stable angina pectoris, enrolled in the beta energy restenosis trial (BERT-1.5), were included. After excluding those who underwent stent implantation, the evaluable population was 22 patients. INTERVENTIONS: Balloon angioplasty and intracoronary radiation followed by quantitative coronary angiography (QCA) and IVUS. Repeat QCA and IVUS were performed at six month follow up. MAIN OUTCOME MEASURES: QCA and IVUS evidence of healing of dissection. Dissection classification for angiography was by the National Heart Lung Blood Institute scale. IVUS proven dissection was defined as partial or complete. The following IVUS defined characteristics of dissection were described in the affected coronary segments: length, depth, arc circumference, presence of flap, and dissection score. Dissection was defined as healed when all features of dissection had resolved. The calculated dose of radiation received by the dissected area in those with healed versus non-healed dissection was also compared. RESULTS: Angiography (type A = 5, B = 7, C = 4) and IVUS proven (partial = 12, complete = 4) dissections were seen in 16 patients following intervention. At six month follow up, six and eight unhealed dissections were seen by angiography (A = 2, B = 4) and IVUS (partial = 7, complete = 1), respectively. The mean IVUS dissection score was 5.2 (range 3-8) following the procedure, and 4.6 (range 3-7) at follow up. No correlation was found between the dose prescribed in the treated area and the presence of unhealed dissection. No change in anginal status was seen despite the presence of unhealed dissection. CONCLUSION: beta radiation appears to alter the normal healing process, resulting in unhealed dissection in certain individuals. In view of the delayed and abnormal healing observed, long term follow up is indicated given the possible late adverse effects of radiation. Although in this cohort no increase in cardiac events following coronary dissections was seen, larger populations are needed to confirm this phenomenon. Stenting of all coronary dissections may be warranted in patients scheduled for brachytherapy after balloon angioplasty.     

Coronary stenting with cardiogenic shock due to acute ascending aortic dissection

A 65-year-old man developed chest pain under cardiogenic shock. Coronary angiography revealed severe stenosis from the ostium of the left main coronary artery(LMCA) to the left anterior descending artery(LAD). Intravascular ultrasound(IVUS) identified a large hematoma that originated from the aorta and extended into the LAD, thereby compressing the true lumen. Type A aortic dissection(TAAD) that involved the LMCA was diagnosed by IVUS. Coronary stenting was performed via the LMCA to the proximal LAD, which resulted in coronary blood flow restoration and no further propagation of dissection. Elective surgical aortic repair was performed 2 wk after the stenting. LMCA stenting under IVUS guidance is effective for prompt diagnosis and precise stent deployment in patients with cardiogenic shock due to TAAD with LMCA dissection.     

Optical coherence tomography in the diagnosis and treatment of spontaneous coronary artery dissection

The diagnosis of spontaneous coronary artery dissection (SCAD) is not always readily apparent on coronary angiography. Even if the diagnosis is suspected, angiography often conveys limited information about the underlying pathology, much of which is crucial for successful percutaneous coronary intervention (PCI). Due to the dissection flap and the resultant double lumen, SCAD poses unique challenges for PCI, specifically in securing wire access to the true lumen without propagation of the dissection. Optical coherence tomography (OCT) is a wire-based intravascular imaging modality with a high resolution of 10-20 μm. We present a case demonstrating the use of OCT in emergency PCI of SCAD, where OCT was integral not only to the diagnosis of SCAD, but also to successful PCI of the condition. It is a valuable aid to PCI in cases where there is uncertainty regarding the precise guidewire location, proving its use in the cardiac catheterization laboratory beyond that of merely a diagnostic tool.     

Intracoronary ultrasound evaluation of interventional technologies

The feasibility and applicability of intravascular ultrasound (IVUS) of the coronary arteries were evaluated in 65 patients undergoing 70 coronary interventional procedures. Morphologic and quantitative analyses were performed with a mechanically rotated IVUS catheter (4.8Fr, 20 MHz) and with orthogonal view cineangiography. A semiautomated edge-detection algorithm was used for cineangiographic quantification. Coronary interventions included 45 percutaneous transluminal coronary angioplasties, 9 excimer lasers, 11 directional coronary atherectomies, 3 rotational atherectomies and 2 stents. Most lesions consisted of a mixture of plaque composition (hard, n = 30; soft, n = 64). Other unique morphologic data by IVUS were plaque topography (eccentric, n = 34; concentric, n = 36) and vessel dissection (IVUS [n = 29] versus angiography [n = 14], p less than 0.05). Postprocedure minimal lumen diameter and cross-sectional area measured by IVUS were larger and poorly correlated with angiography (r = 0.28, standard error of the estimate = 0.52 mm; r = 0.08, standard error of the estimate = 1.0 cm2, respectively). IVUS is more sensitive than angiography when assessing postintervention lesion characteristics including vessel dissection and plaque morphology. Catheter-based ultrasound appears to be a useful adjunct to contrast angiography when evaluating and comparing the therapeutic impact of conventional percutaneous transluminal coronary angioplasty with new technologies.