Detection of impending perfusion deficits by intraoperative computed tomography (iCT) in aneurysm surgery of the anterior circulation

Background The aim of our study was to evaluate the additional benefit of intraoperative computed tomography (iCT), intraoperative computed tomography angiography (iCTA), and intraoperative computed tomography perfusion (iCTP) in the intraoperative detection of impending ischemia to established methods (indocyanine green videoangiography (ICGVA), microDoppler, intraoperative neuromonitoring (IONM)) for initiating timely therapeutic measures. Methods Patients with primary aneurysms of the anterior circulation between October 2016 and December 2019 were included. Data of iCT modalities compared to other techniques (ICGVA, microDoppler, IONM) was recorded with emphasis on resulting operative conclusions leading to inspection of clip position, repositioning, or immediate initiation of conservative treatment strategies. Additional variables analyzed included patient demographics, aneurysm-specific characteristics, and clinical outcome. Results Of 194 consecutive patients, 93 patients with 100 aneurysms received iCT imaging. While IONM and ICGVA were normal, an altered vessel patency in iCTA was detected in 5 (5.4%) and a mismatch in iCTP in 7 patients (7.5%). Repositioning was considered appropriate in 2 patients (2.2%), where immediate improvement in iCTP could be documented. In a further 5 cases (5.4%), intensified conservative therapy was immediately initiated treating the reduced CBP as clip repositioning was not considered causal. In terms of clinical outcome at last FU, mRS0 was achieved in 85 (91.4%) and mRS1-2 in 7 (7.5%) and remained mRS4 in one patient with SAH (1.1%). Conclusions Especially iCTP can reveal signs of impending ischemia in selected cases and enable the surgeon to promptly initiate therapeutic measures such as clip repositioning or intraoperative onset of maximum conservative treatment, while established tools might fail to detect those intraoperative pathologic changes.

The diagnostic value of Doppler ultrasonography after pediatric kidney transplantation

Ultrasonography (US) plays a major diagnostic role in the pre- and post-transplant evaluation of recipient and donor. In most cases, US remains the only necessary imaging modality. After pediatric kidney transplantation, US can ensure immediate bedside diagnosis of vessel patency and possible postoperative non-vascular complications. Criteria for US diagnosis of kidney vessel thrombosis and stenosis in the transplant will be presented. Non-vascular complications after kidney transplantation include hydronephrosis, hematoma, lymphocele, and abscess. US can detect suggestive, but nevertheless non-specific, acute signs (sudden increase in volume and elevated resistive index), and chronic rejection, which therefore remains a histological diagnosis. US is of little or no help in detection of tubular necrosis or drug toxicity, but it can exclude other differential diagnoses. This educational review provides a practical and systematic approach to a multimodal US investigation of the kidney transplant. It includes a short overview on possible indications for contrast-enhanced ultrasonography (CEUS) in children after kidney transplantation.

180 Improving Wall Access When Using Double Clamps for Microsurgical Anastomosis – A New Technique

Microvascular techniques and instrumentation have continually evolved since the advent of clinical microsurgery in the 1970’s. These refinements and improved patient selection have led to increased vessel patency and flap survival rates. However, a fundamental principle which has not changed over this time period is comfort and proper operating microscope set-up. Both these factors were described as a precondition of microsurgical success by the late pioneer of microsurgery himself, Robert Acland. Suboptimal comfort or set-up can negatively impact on access to the surgical field leading to improper technique and if significant enough, anastomotic thrombosis. We describe a new technique aimed at improving wall access when using double clamps for microsurgical anastomosis.

Acute Coronary Syndromes (ACS)—Unravelling Biology to Identify New Therapies—The Microcirculation as a Frontier for New Therapies in ACS

In acute coronary syndrome (ACS) patients, restoring epicardial culprit vessel patency and flow with percutaneous coronary intervention or coronary artery bypass grafting has been the mainstay of treatment for decades. However, there is an emerging understanding of the crucial role of coronary microcirculation in predicting infarct burden and subsequent left ventricular remodelling, and the prognostic significance of coronary microvascular obstruction (MVO) in mortality and morbidity. This review will elucidate the multifaceted and interconnected pathophysiological processes which underpin MVO in ACS, and the various diagnostic modalities as well as challenges, with a particular focus on the invasive but specific and reproducible index of microcirculatory resistance (IMR). Unfortunately, a multitude of purported therapeutic strategies to address this unmet need in cardiovascular care, outlined in this review, have so far been disappointing with conflicting results and a lack of hard clinical end-point benefit. There are however a number of exciting and novel future prospects in this field that will be evaluated over the coming years in large adequately powered clinical trials, and this review will briefly appraise these.

Pulmonary Vein Stenosis in Children: A Programmatic Approach Employing Primary and Anatomic Therapy

Pulmonary vein stenosis (PVS) is a difficult condition to treat due to recurrence and progression. In 2017, we developed a comprehensive PVS Program at our center to address the multidisciplinary needs of these patients. We discuss the components of our program and our approach to these patients, using a combination of primary (medical) therapy in addition to anatomic therapy to preserve vessel patency. A multidisciplinary approach to treating these challenging patients is critical.

The Evolution of Safe and Effective Coaguligands for Vascular Targeting and Precision Thrombosis of Solid Tumors and Vascular Malformations

In cardiovascular and cerebrovascular biology, control of thrombosis and the coagulation cascade in ischemic stroke, myocardial infarction, and other coagulopathies is the focus of significant research around the world. Ischemic stroke remains one of the largest causes of death and disability in developed countries. Preventing thrombosis and protecting vessel patency is the primary goal. However, utilization of the body’s natural coagulation cascades as an approach for targeted destruction of abnormal, disease-associated vessels and tissues has been increasing over the last 30 years. This vascular targeting approach, often termed “vascular infarction”, describes the deliberate, targeted delivery of a thrombogenic effector to diseased blood vessels with the aim to induce localized activation of the coagulation cascade and stable thrombus formation, leading to vessel occlusion and ablation. As systemic delivery of pro-thrombotic agents may cause consternation amongst traditional stroke researchers, proponents of the approach must suitably establish both efficacy and safety to take this field forward. In this review, we describe the evolution of this field and, with a focus on thrombogenic effectors, summarize the current literature with respect to emerging trends in “coaguligand” development, in targeted tumor vessel destruction, and in expansion of the approach to the treatment of brain vascular malformations.

Selective intra-carotid blood cooling in acute ischemic stroke: A safety and feasibility study in an ovine stroke model

Selective therapeutic hypothermia (TH) showed promising preclinical results as a neuroprotective strategy in acute ischemic stroke. We aimed to assess safety and feasibility of an intracarotid cooling catheter conceived for fast and selective brain cooling during endovascular thrombectomy in an ovine stroke model. Transient middle cerebral artery occlusion (MCAO, 3 h) was performed in 20 sheep. In the hypothermia group (n = 10), selective TH was initiated 20 minutes before recanalization, and was maintained for another 3 h. In the normothermia control group (n = 10), a standard 8 French catheter was used instead. Primary endpoints were intranasal cooling performance (feasibility) plus vessel patency assessed by digital subtraction angiography and carotid artery wall integrity (histopathology, both safety). Secondary endpoints were neurological outcome and infarct volumes. Computed tomography perfusion demonstrated MCA territory hypoperfusion during MCAO in both groups. Intranasal temperature decreased by 1.1 °C/3.1 °C after 10/60 minutes in the TH group and 0.3 °C/0.4 °C in the normothermia group (p < 0.001). Carotid artery and branching vessel patency as well as carotid wall integrity was indifferent between groups. Infarct volumes (p = 0.74) and neurological outcome (p = 0.82) were similar in both groups. Selective TH was feasible and safe. However, a larger number of subjects might be required to demonstrate efficacy.

The Early Outcomes of BeGraft Peripheral Plus in Branched Endovascular Repair of Thoracoabdominal Aneurysms

Objective No bridging stent-graft (BSG) has been specifically designed for branched endovascular aortic repair (BEVAR) and therefore different “off-label” stent-grafts have been used. Recently, a third generation of balloon-expandable stent-graft has become available. Here we evaluate the outcomes of the BeGraft Peripheral Plus (B+) used as a BSG for internal/externalor inner branches during BEVAR. Materials and Methods Consecutive patients undergoing BEVAR using B+ as a BSG since its release in 2017 were included into the study. The primary endpoints were technical success and target vessel patency during follow-up. Secondary endpoints included the need for adjunct extension and relining of the BSG, branch instability rate, including occlusion, reinterventions for restonosis, kink, fracture, or endoleak (types 1 and 3). Results A total of 163 visceral branches in 46 patients were included with a median follow-up 15 months (4–36 months). Primary technical success was achieved in all visceral branches (69 inner branches and 94 internal/external branches) with the exception of 1 BSG that required serial dilatation until full expansion was achieved with overall branch patency was 98% at 2 years. An additional stent-graft was necessary in 35 branches (21%) following deployment of a B+ BSG to cover a longer bridging distance and optimize the distal and proximal sealing. Relining of B+ BSG was not routinely carried out during the index procedure and a self-expanding uncovered nitinol stent was necessary in only 3% of branches to smooth the distal transition zone between the BSG and target vessel. There were 4 events (2.4%) of branch related instability, including 2 occlusions and 2 late reinterventions for a partial in-stent-graft thrombosis. Conclusion Our study findings show satisfactory early outcomes of B+ as a BSG in BEVAR with low occlusion and reintervention rates. Extensions of BSG might be required to achieve adequate seal in the target vessels but routine relining BSG in branches was not required.

Intraoperative Transradial Angiogram

Intraoperative angiogram (IOA) is a valuable tool for cerebrovascular surgery. It confirms surgical outcomes for a variety of pathologies. It allows early identification of any residue or compromise of a parent vessel. This chapter will delve into the advantages, limitations, and technical nuances of IOA via a radial approach. IOA is a valuable tool for cerebrovascular surgery. IOA allows early diagnosis and identification of any residue and obviates the need for postoperative diagnostic angiogram. It confirms surgical outcomes for a variety of pathologies such as aneurysm occlusion and parent vessel patency, arteriovenous malformation resection, dural fistula ligation, bypass patency, and adequate carotid revascularization after endarterectomy. Though there are alternatives, such as indocyanine green fluorescence (ICGA) angiography, formal angiography remains the gold standard as it overcomes the limitations of ICGA. Femoral access has been the main approach for IOA with an excellent safety profile. Recently the radial approach has been gaining wide interest among neurointerventionalists, and there are several advantages for the radial approach over the femoral approach in IOA.