The Pathophysiology and the Management of Radiocontrast-Induced Nephropathy

Contrast-induced nephropathy (CIN) is an impairment of renal function that occurs after the administration of an iodinated contrast medium (CM). Kidney dysfunction in CIN is considered transient and reversible in most cases. However, it is the third most common cause of hospital-acquired acute kidney injury and is associated with increased morbidity and mortality, especially in high-risk patients. Diagnostic and interventional procedures that require intravascular CM are being used with increasing frequency, especially among the elderly, who can be particularly susceptible to CIN due to multiple comorbidities. Therefore, identifying the exact mechanisms of CIN and its associated risk factors is crucial not only to provide optimal preventive management for at-risk patients, but also to increase the feasibility of diagnostic and interventional procedure that use CM. CM induces kidney injury by impairing renal hemodynamics and increasing the generation of reactive oxygen species, in addition to direct cytotoxicity. Periprocedural hydration is the most widely accepted preventive strategy to date. Here, we review the latest research results on the pathophysiology and management of CIN.

Surgical Management of Lymphatic Leakage

Lymphatics are found in almost every organ in the body, and they produce a variety of waste products that must be eliminated. lymphatic leakage is a typical occurrence. It can cause immunodeficiency as well as nutritional issues. Furthermore, it has a significant morbidity and death rate, depending on the existence of an underlying illness. Lymphatic leakage can be congenital, traumatic, or cancerous, and occurs when the lymphatic system is disrupted. It might take the following forms: Chylothorax, Lymphatic Fistula, Chylous Ascites. treatment of lymph leaks includes: reduction of lymphatic flow through physiological or pharmacological manipulation; replacement of fluid and electrolytes, as well as interventional procedure and/or direct surgical closure. In this review we’ll be discussing lymphatic system anatomy, its leakage and its management.

Validation of the Turkish version of the Pain Sensitivity Questionnaire in patients with chronic pain

Objective The Pain Sensitivity Questionnaire (PSQ) is a clinically beneficial instrument that has been proven to be correlated with various experimental pain sensitivity assessments in healthy people and in patients with chronic pain. In this study, we aimed to translate the PSQ into Turkish (PSQ-T) and validate it for the measurement of pain sensitivity among Turkish people. Methods Seventy-three patients with chronic back pain who were planning to undergo an interventional procedure completed the Brief Pain Inventory-Short Form (BPI-SF), Beck Depression Inventory (BDI), Beck Anxiety Inventory, Pain Catastrophizing Scale, and PSQ prior to their procedure. Subcutaneous infiltration of lidocaine was used as a standardized experimental pain stimulus. Pain was evaluated using a visual analog scale (VAS 1: infiltration in the hand, and VAS 2: infiltration in the procedure area) Results Scores on the PSQ-T were significantly correlated with those on the BPI-SF. A significant positive relationship was observed between VAS 1 and VAS 2 values and the PSQ-T score, BPI pain score, and BPI interference score. Conclusions The PSQ-T can be used as a valid and reliable tool for the assessment of pain sensitivity in the Turkish population.

Interventional Treatment of Access Site Complications During Transfemoral TAVI: A Single Center Experience

Introduction: Transcatheter aortic valve implantation (TAVI) has rapidly developed over the last decade and is nowadays the treatment of choice in the elderly patients irrespective of surgical risk. The outcome of these patients is mainly determined not only by the interventional procedure itself, but also by its complications.Material and Methods: We analyzed the outcome and procedural events of transfemoral TAVI procedures performed per year at our institution. The mean age of these patients is 79.2 years and 49% are female. All the patients underwent duplex ultrasonography of the iliac arteries and inguinal vessels before the procedure and CT of the aorta and iliac arteries.Results: Transfemoral access route is associated with a number of challenges and complications, especially in the patients suffering from peripheral artery disease (PAD). The rate of vascular complications at our center was 2.76% (19/689). Typical vascular complications (VC) include bleeding and pseudoaneurysms at the puncture site, acute or subacute occlusion of the access vessel, and dissection or perforation of the iliac vessels. In addition, there is the need for primary PTA of the access pathway in the presence of additional PAD of the common femoral artery (CFA) and iliac vessels. Balloon angioplasty, implantation of covered and uncovered stents, lithoplasty, and ultrasound-guided thrombin injection are available to treat the described issues.Conclusion: Interventional therapy of access vessels can preoperatively enable the transfemoral approach and successfully treat post-operative VC in most of the cases. Training the heart team to address these issues is a key focus, and an interventional vascular specialist should be part of this team.

Successful integration of interdisciplinary pain rehabilitation and spinal cord stimulation for chronic naive back pain

Spinal cord stimulation for naive back pain is a therapeutic option that is rarely considered, especially when conventional stimulation parameters are used. Interdisciplinary pain rehabilitation program is another less feasible but effective therapeutic approach for the management of chronic pain that is not usually used in conjunction with interventional procedures.This case report presents a successful integration of an interdisciplinary pain rehabilitation program with an interventional procedure spinal cord stimulation using conventional stimulation parameters in a patient with chronic, predominantly nociceptive to nociplastic, naïve back pain.

An adaptive optimal viewing angle determination algorithm for TEVAR operation

Background The determination of the right x-ray angiography viewing angle is an important issue during the treatment of thoracic endovascular aortic repair (TEVAR). An inaccurate projection angle (manually determined today by the physicians according to their personal experience) may affect the placement of the stent and cause vascular occlusion or endoleak. Methods Based on the acquisition of a computed tomography angiography (CTA) image before TEVAR, an adaptive optimization algorithm is proposed to determine the optimal viewing angle of the angiogram automatically. This optimal view aims at avoiding any overlapping between the left common carotid artery and the left subclavian artery. Moreover, the proposed optimal procedure exploits the patient-specific morphology to adaptively reduce the potential foreshortening effect. Results Experimental results conducted on thirty-five patients demonstrate that the optimal angiographic viewing angle based on the proposed method has no significant difference when compared with the expert practice (p = 0.0678). Conclusion We propose a method that utilizes the CTA image acquired before TEVAR to automatically calculate the optimal C-arm angle. This method has the potential to assist surgeons during their interventional procedure by providing a shorter procedure time, less radiation exposure, and less contrast injection.

Investigation of the Pressure and Flow Dynamics during Aspiration Thrombectomy: A Mathematical Modelling Study

Aspiration thrombectomy is a life-saving interventional procedure to remove a blood clot from the brain of stroke patients. The pressure and blood flow dynamics during this procedure are crucial in determining the clinical outcomes. A mathematical model based on Hagen-Poiseuille law of fluid flow in a tube is adapted to simulate the pressure and fluid flow characteristics in an in vitro model of an occluded and unoccluded cerebrovascular network that mimics a poor (unilateral) and good (symmetrical) collateral flow within the Circle of Willis. The results show that in the absence of an occlusion, the pressure and pressure drop are higher in the symmetrical network compared to that in the unilateral network. This is due to the additional limb in the symmetrical network that must be supplied, which is absent in the unilateral network. In the presence of an occlusion, the flow reduces in the obstructed vessel, the collateral flow, overall pressure and pressure drop increases in both systems, but is higher for the symmetrical network. The results compare qualitatively with those observed in in vitro studies and with clinical observations. The theoretical framework lays the foundation for more advanced models for the pressure and blood flow dynamics towards clinical applicability.

Interventional cardiology in times of COVID-19: impact on a terciary centre

Introduction Cardiovascular diseases are the leading cause of death worldwide and the pandemic caused by coronavirus disease 2019 (COVID-19) has forced profound changes in the care of patients with cardiac conditions. In Portugal, an increase in mortality beyond that attributed solely to COVID-19 was observed. We aimed to realize how COVID-19 has changed the activity of our Interventional Cardiology Unit. Methods We retrospectively assessed all patients submitted to any interventional procedure in 2019 and 2020 in our hospital. A total of 7621 patients and 9163 procedures were evaluated. The mean weekly numbers of coronarography, angioplasty, right heart catheterization and structural heart intervention during 2019 were assessed and were compared with the first COVID-19 wave (comprising March and April 2020) and the second COVID-19 wave (including the time period from October to end of December 2020). Results Mean age was 65.2±16.6 years with 72% being male. In the first COVID-19 wave there was a significant reduction in the mean weekly numbers of all procedures, with a 64% decline in coronarographies (30.9±29.3 vs 87.2±12.9, P<0.001), 48% in angiographies (15.7±10.9 vs 30.2±5.7, P=0.004), 51% in right heart catheterizations (5.3±5.9 vs 10.9±4.5, P=0.002) and 57% in structural heart interventions (1.1±1.9 vs 2.6±2, P=0.044). Although there was an evident recovery in activity (figure 1), comparing to 2019, the second wave also showed a significant lower number of procedures, with 24% fewer coronarographies (66.6±20.6 vs 87.2±12.9, P=0.003) and 13% fewer angiographies (26.4±7.6 vs 30.2±5.7, P=0.004). Contrariwise, in the second wave there was no difference in the number of right heart catheterizations (7.3±6.1 vs 10.9±4.5, P=0.055) or structural heart interventions (1.6±1.6 vs 2.6±2, P=0.106). Conclusions In our Interventional Cardiology Unit, COVID-19 led to a significant reduction of procedures in the first and second pandemic waves. The effect on the increase in morbidity and mortality has yet to be determined. Health authorities should focus attention in defining measures to amend the consequences of this documented activity reduction. FUNDunding Acknowledgement Type of funding sources: None. Figure 1

Fiber-optic laser energy for pulmonary artery denervation: results of an experimental study

Background/Introduction Pulmonary artery denervation (PADN) is an interventional procedure aiming to modulate and correct pulmonary artery (PA) pressure. New technologies and energy sources are being tested currently. However, the effects of laser energy on the PA wall are unknown. Purpose To assess the acute effects and impact of laser energy for PADN procedure in normotensive sheep by applying different power settings and session times. Methods A total of 10 normotensive Katumsky sheep were included in the experiment. Percutaneous vascular access was performed under general anesthesia. A fiberoptic open-irrigated non-steerable catheter was introduced via a femoral vein through a steerable sheath. Laser applications were applied in the PA trunk and the proximal areas of the right and left PA under fluoroscopic guidance with a 5mm distance between points in the anterior, posterior and lateral walls. Applications were delivered with power 10–30W, 10–35s in duration; irrigation flow 40ml/min. After the procedure, experimental animals were euthanized and underwent an autopsy. PA samples were obtained regardless of the absence of visible laser-related lesions for histological analysis (hematoxylin staining) and immunohistochemical labelling (S100). Results A total of 108 ablation sessions were performed, 33 in the right PA, 30 in the left PA and 42 in the PA trunk. During macroscopic examination, laser-related lesions described as irregular brown hemorrhage spots and rough defects observed in the PA endothelium were not homogenous in all experimental animals. Thermal injuries either in the left or right lung lobes were identified in 5 (50%) experimental animals when using 30W during 10–20sec. In 5 (50%) sheep no collateral lung injuries were identified when using 10–20W from 20–35s. A total of 64 PA fragments underwent microscopic examination, acute thermal tissue lesions were observed in all experimental animals despite the absence of laser-related lesions in the PA endothelium; dissection, edema, disruption trough tunica layers, hemorrhage and necrosis at different depth walls. The most frequent nerve damage was obtained with 20W ablation: 5/8 PAs vs, 1/6 with 10–15W and 1/14 with 25–30W (P=0.01). At the same time, there was no difference in intima necrosis between the groups (1/6, 2/8 and 4/14 for 10–15, 20 and 25–30W groups, respectively). Conclusion(s) Percutaneous PA laser ablation is feasible, reduction of perivascular nerve expression is seen most frequently, when 20W/20–35 s ablation is performed. PA lesions may differ in depth and characteristics, and perivascular nerve damage might be seen in cases with preserved intima. FUNDunding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Grant of the Ministry of Science and Higher Education of the Russian Federation

The role of epidural steroid injections in the treatment of pain in patients with degenerative changes in the lumbar spine

Epidural steroid injections of the lumbar spine are a common interventional procedure that is used to alleviate radicular pain resulting from degenerative changes in the spine. Although several studies have compared epidural steroid injections with placebo with favorable outcomes, randomized controlled trials in this direction are needed. The purpose of the study was to evaluate the effectiveness of the use of epidural steroid injections in the treatment of pain in patients with degenerative lesions of the lumbar spine. During the study, 262 patients with degenerative lesions of the spine at one or two levels of the vertebral-motor segment (VMS) were selected. Epidurally transforaminally under fluoroscopic control all patients received steroid injections at the appropriate level (s) of VMS on the basis of the rehabilitation department of the Institute of Traumatology and Orthopedics of the National Academy of Medical Sciences of Ukraine during 2017-2019. Of the 262 patients who received epidural steroid injections, 204 were able to reduce pain and avoid surgery within one year. However, 58 patients experienced only slight pain relief and were recommended surgical treatment. In our study, patients with negative results were offered surgery after 1.98 ESI procedures with an interval of 3.7 months. In the group of operated patients, the preliminary use of steroid injections did not bring relief by the results of Oswestry Disability Index (ODI) and Visual Analog scale (VAS), however, the condition of these patients improved significantly after surgery (p<0.05). The use of epidural injections is possible as a first-line therapy in patients with moderate functional limitations, which can subsequently be directed to surgery in the absence of a positive result.