A contemporary assessment of devices for Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA): resource-specific options per level of care.

PURPOSE: Use of Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) as adjunct for temporary hemorrhage control in patients with exsanguinating torso hemorrhage is increasing. Characteristics of aortic occlusion balloons (AOB) are diverse and evolving as efforts are made to improve the technology. It is important to select a device that fits the requirements of the medical situation to minimize the risk of failure and complications. The aim of this study is to appraise guidance in the choice of an AOB in a specific situation. METHODS: We assessed 29 AOB for differences and outline possible advantages and disadvantages of each. Bending stiffness was measured with a three-point bending device. RESULTS: Diameter of the AOB ranged from 6 (ER-REBOA™) to 10 (Coda®-46) French. However, some need large-bore access sheaths up to 22 French (Fogarty®-45 and LeMaitre®-45) or even insertion via cut-down (Equalizer™-40). Bending stiffness varied from 0.08 N/mm (± 0.008 SD; Coda®-32) to 0.72 N/mm (± 0.024 SD; Russian prototype). Rescue Balloon™ showed kinking of the shaft at low bending pressures. The only non-compliant AOB is REBOA Balloon®. ER-REBOA™, Fogarty®, LeMaitre®, REBOA Balloon®, and Rescue Balloon™ are provided with external length marks to assist blind positioning. CONCLUSION: In resource-limited settings, a guidewire- and fluoroscopy-free, rather stiff device, such as ER-REBOA™, Fogarty®, and LeMaitre®, is warranted. Of these devices, ER-REBOA™ is the only catheter compatible with seven French sheaths and specifically designed for emergency hemorrhage control. Of the over-the-wire devices, Q50® has several features that facilitate use and reduce the risk of malplacement or vessel damage.

Affordable and low-maintenance obstetric devices.

OBJECTIVE: Adequate obstetric care requires the availability of essential diagnostic and management equipment; however, for centers with budget restrictions, the acquisition and maintenance of these devices can pose major challenges. The purpose of the present paper is to disseminate knowledge about the availability of affordable and low-maintenance obstetric devices, which might help to save lives in low- and medium-resource countries. METHOD: Over the course of 2015-2018, the International Federation of Gynecology and Obstetrics (FIGO) Safe Motherhood and Newborn Health Committee acquired information from different clinical and commercial sources regarding the availability of affordable and low-maintenance essential obstetric devices. RESULTS: The Committee identified several devices that met the criteria of low cost and ease of maintenance: a winding handheld Doppler device for intermittent auscultation; a portable continuous fetal heart rate monitor; a validated semi-automated blood pressure monitor; the Foley catheter balloon for labor induction in women with an unfavorable cervix; reusable metal and plastic vacuum cups and manual pumps; an intrauterine tamponade balloon; and the non-pneumatic anti-shock garment. CONCLUSION: Several affordable and low-maintenance obstetric devices are currently available that offer the potential to save lives in resource-constrained settings.

Design of a cost-effective, hemodynamically adjustable model for resuscitative endovascular balloon occlusion of the aorta (REBOA) simulation.

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is an adjunct technique for salvaging patients with noncompressible torso hemorrhage. Current REBOA training paradigms require large animals, virtual reality simulators, or human cadavers for acquisition of skills. These training strategies are expensive and resource intensive, which may prevent widespread dissemination of REBOA. We have developed a low-cost, near-physiologic, pulsatile REBOA simulator by connecting an anatomic vascular circuit constructed out of latex and polyvinyl chloride tubing to a commercially available pump. This pulsatile simulator is capable of generating cardiac outputs ranging from 1.7 to 6.8 L/min with corresponding arterial blood pressures of 54 to 226/14 to 121 mmHg. The simulator accommodates a 12 French introducer sheath and a CODA balloon catheter. Upon balloon inflation, the arterial waveform distal to the occlusion flattens, distal pulsation within the simulator is lost, and systolic blood pressures proximal to the balloon catheter increase by up to 62 mmHg. Further development and validation of this simulator will allow for refinement, reduction, and replacement of large animal models, costly virtual reality simulators, and perfused cadavers for training purposes. This will ultimately facilitate the low-cost, high-fidelity REBOA simulation needed for the widespread dissemination of this life-saving technique.

Device closure of interatrial communications: peri-interventional echocardiographic assessment.

The interventional closure of interatrial communications requires peri-interventional echocardiographic assessment and guidance to make those treatments as safe as possible. Transoesophageal echocardiography (TEE) including real-time three-dimensional (RT-3D) imaging, later complemented and in part replaced by intracardiac echocardiography (ICE), has become established as the standard approach to prepare for and to guide the interventional treatment of interatrial communications. Accurate imaging of the anatomic features of the particular communication is critical for case selection, planning, and intraprocedural guidance. Especially in the atrial septal defect (ASD) closure, which tends to be more challenging than the patent foramen ovale (PFO) closure, a certain risk of severe complications remains and may result from suboptimal device performance. Other complications may be related to discontinuous use of echocardiographic monitoring. Image fusion and RT-3D ICE are currently under clinical testing and might be suitable to facilitate spatial orientation. Nowadays, two-dimensional ICE is the method of choice for guiding percutaneous device closure, especially of ASDs and 'complex' PFOs. Uninterrupted TEE under deep sedation is an alternative. In contrast, the closure of 'simple' PFOs will often require nothing but final confirmation of the result, and therefore, short echocardiographic viewing is sufficient in many cases.

Clinical value of stereoscopic three-dimensional echocardiography in assessment of atrial septal defects: feasibility and efficiency.

Stereoscopic three-dimensional echocardiography(S-3DE) is a novel displaying technology based on real-time 3-dimensional echocardiography (RT-3DE). Our study was to evaluate the feasibility and efficiency of S-3DE in the diagnosis of atrial septal defect (ASD) and its use in the guidance for transcatheter ASD occlusion. Twelve patients with secundum ASD underwent RT-3DE examination and 9 of the 12 were subjected to transcatheter closure of ASD. Stereoscopic vision was generated with a high-performance volume renderer with red-green stereoscopic glasses. S-3DE was compared with standard RT-3D display for the assessment of the shape, size, and the surrounding tissues of ASD and for the guidance of ASD occlusion. The appearance rate of coronary sinus and the mean formation time of the IVC, SVC were compared. Our results showed that S-3DE could measure the diameter of ASD accurately and there was no significant difference in the measurements between S-3DE and standard 3D display (2.89+/-0.73 cm vs 2.85+/-0.72 cm, P>0.05; r=0.96, P<0.05). The appearance of coronary sinus for S-3DE was higher as compared with the standard 3D display (93.3% vs 100%). The mean time of the IVC, SVC for S-3DE monitor was slightly shorter than that of the standard 3D display (11.0+/-3.8 s vs 10.3+/-3.6 s, P>0.05). The mean completion time of interventional procedure was shortened with S-3DE display as compared with standard 3D display (17.3+/-3.1 min vs 23.0+/-3.9 min, P<0.05). Stereoscopic three-dimensional echocardiography could improve the visualization of three-dimensional echocardiography, facilitate the identification of the adjacent structures, decrease the time required for interventional manipulation. It may be a feasible, safe, and efficient tool for guiding transcatheter septal occlusion or the surgical interventions.

Distal filtration versus flow reversal: An ex vivo assessment of the choices for carotid embolic protection.

OBJECTIVES: Choices for embolic protection during carotid stent procedures include distal filtration (DF) and proximal occlusion with flow reversal (POFR). DF devices are widely used but have produced only modest improvements in clinical outcomes. There is less experience with POFR devices but single center reports suggest reduced emboli detected by transcranial Doppler (TCD). To determine if POFR offers a significant improvement in embolic protection, we tested five DF devices and two POFR devices with 8F and 10F sheath design in an ex vivo angioplasty system using human carotid plaques excised en bloc. Physiologic pressures and flows were used and the efficiency of plaque fragment removal by these devices compared. METHODS: Thirty-three human carotid plaques removed en bloc were secured in tailored polytetrafluoroethylene (PTFE) grafts. The distal PTFE was either 6 mm or 5 mm inner diameter (ID). Saline was delivered through the excised carotid plaque as follows: a cleaning 50 mL flush was done prior to the angioplasty procedure and discarded; further flushes of forward flow were done with five pressurized "pulsations" of 10 mL each (50 mL), peak pressure 140 mm Hg. Balloon angioplasty was done with a 4 mm and then a 6 mm balloon. DF flushes were applied after each angioplasty and "postprocedure" after the device was removed. With POFR, 50 mL were collected through the sheath after balloon angioplasty by either back-pressure of 20 mm Hg, 40 mm Hg or 60 mm Hg, or by aspiration. Postangioplasty pressurized forward flush of 50 or 100 mL was done as described. Each flush was collected, centrifuged, and examined for plaque fragments. Fragments greater than 60 microns were sized and counted on a 100 micron grid. RESULTS: When DF devices were used in 6 mm lumen PTFE, the percent of fragments trapped was poor (13.7% to 27.8%). There were no statistically significant differences between the devices. The capture of fragments improved (22% vs 51.4%, P < .001) when devices appropriate for a 6 mm lumen were used in a 5 mm PTFE "ICA", functionally over-sizing the devices. POFR efficiency improved with increasing back-pressures and with repeated aspirations. Postprocedure, successive flushes of pressurized forward flow yielded additional plaque fragments and when the efficiency of POFR was assessed with forward flushing volumes similar to those used for DF, the efficiencies were similar, although larger fragments were more efficiently removed with POFR. CONCLUSION: In our model, both protection strategies were less than ideal. For POFR, high back pressures or multiple aspirations improve the efficiency of cerebral protection but additional fragments were released by pressurized flow even after aspiration of 150 mL of saline. DF devices create a pressure gradient and fragments apparently went around the device with pressurized flow in our PTFE lumen. Over-sizing of DF devices partially corrected this problem and increased over all DF efficiency to be comparable to POFR for smaller fragments but not for larger fragments.

Endoscopic fiberoptic assessment of balloon occlusion of the pulmonary vein ostium in humans: comparison with phased-array intracardiac echocardiography.

BACKGROUND: Anatomic pulmonary vein (PV) variants may affect the ability to position balloon catheter systems at the left atrium (LA)-PV junction with complete circumferential contact, resulting in ineffective PV isolation. OBJECTIVES: This feasibility study was performed to assess the use of the fiberoptic endoscopic light ring balloon catheter (ELRBC) in accessing the PVs and achieving adequate contact at the LA-PV junction, as visualized by phased-array intracardiac echocardiography (ICE). METHODS: We enrolled five men (mean age 59 +/- 8 years) with drug-refractory atrial fibrillation. The ELRBC consisted of a 25-mm balloon catheter with an integral endoscope contained within the balloon and a custom deflectable sheath. At the end of conventional PV isolation, the ELRBC was inserted into the LA in an attempt to position the balloon at each PV ostium. The real position of the ELRBC at this level was assessed by ICE in all patients. RESULTS: All but two PVs (right inferior PVs) (89%) were accessed with the ELRBC in a mean time of 17 +/- 3 minutes, and complete circumferential contact was visualized with the fiberoptic endoscopic component in 15 of 16 PVs accessed (94%). Contact was also confirmed by the absence of color Doppler flow through the balloon-occluded PV, as seen on ICE. On two occasions a gap was seen with the fiberoptic endoscope and visualized by the ICE only after optimization of the echo window. No complications were observed. CONCLUSIONS: The ELRBC is able to access the PV without complications. The endoscope and ICE were complementary for positioning of the balloon at the LA-PV junction and for the definition of circumferential contact.

Assessment of atrial septal defect size with 3D-transesophageal echocardiography: comparison with balloon method.

BACKGROUND: Transcatheter closure of atrial septal defect (ASD) is an alternative approach to surgery in selected patients. Balloon stretched diameter (BSD) is considered as the standard way of measuring ASD size. Three-dimensional transesophageal echocardiography (3D-TEE) provides views of the ASD allowing its measurement and identifying its spatial relation with neighboring structures. Our aim was to compare the BSD and 3D-TEE methods to measure the ASD size before transcatheter closure. METHODS AND RESULTS: Seventy-six consecutive patients were enrolled for ASD device closure. Three-dimensional transesophageal echocardiography and balloon sizing were adequately performed in 70 patients before the defect closure. The mean maximal diameter measured by 3D-TEE was 20 +/- 15 mm (range 10-28) while the mean BSD was 22 +/- 4.8 mm (range 9-31). When comparing the 3D-TEE and transcatheter measurements, there was a good correlation between the two methods (y = 3.15 + 0.77x; r = 0.8). The defect as viewed by 3D-TEE was unique in 54 patients and multiple in 16 patients. In patients with a single defect, the correlation between the two methods was high (y = 1.74 + 0.84x; r = 0.85) while patients with multiple ASDs, the correlation was poor (y = 12.4 + 0.4x; r = 0.45). Transcatheter closure was performed successfully in 86%. The mean size of the Amplatzer device was 23 +/- 4.8 mm (range 4-32). The reference to choose the size of the device was the BSD in single defects and the 3D-TEE maximal diameter in multiple defects. CONCLUSION: Three-dimensional transesophageal echocardiography and transcatheter methods are two complementary techniques for the success of transcatheter ASDs closure.

Echocardiographic assessment and percutaneous closure of multiple atrial septal defects.

Atrial septal defect closure is now routinely performed using a percutaneous approach under echocardiographic guidance. Centrally located, secundum defects are ideal for device closure but there is considerable morphological variation in size and location of the defects. A small proportion of atrial septal defects may have multiple fenestrations and these are often considered unsuitable for device closure. We report three cases of multiple atrial septal defects successfully closed with two Amplatzer septal occluders.

Surgical and transcatheter (Amplatzer) closure of atrial septal defects: a prospective comparison of results and cost.

OBJECTIVE: To compare effectiveness, complications, and cost of Amplatzer with surgical atrial septal defect (ASD) closure. DESIGN: Prospective study. SETTING: Tertiary cardiac referral centre. PATIENTS: 43 consecutive patients (excluding non-UK residents) aged between 2.1 and 56.8 years (median 7) undergoing ASD closure. MAIN OUTCOME MEASURES: Procedural success, complications, regression of right ventricular dilatation (up to one year postprocedure), cost, inpatient stay, and home convalescent time. RESULTS: Amplatzer ASD closure was successful in 24 of 27 (89%) patients. Surgical closure was successful in all 19 cases. Cardiac complications affecting management occurred in three (11%) of the Amplatzer group (two procedural failures, one device embolisation) and 4 of 19 (21%) surgical patients (one pericardial pain, one global pericardial effusion requiring drainage, and one patient with anaemia requiring haematinics in addition to an incidental pericardial effusion and one further incidental pericardial effusion) (p = NS). There were complications that did not affect management in a further 5 of 19 surgical patients. There was no significant difference in regression of right ventricular dilatation by six months postprocedure (median right ventricular end diastolic diameter decrease: Amplatzer group 17.5%, surgical group 15.1%; median cardiothoracic ratio decrease: Amplatzer 7.9%, surgical 7.5%). Both hospital stay and home convalescent times were significantly shorter after Amplatzer closure (median hospital stay: Amplatzer one day, surgery six days; median convalescent time: Amplatzer two weeks, surgery 5.5 weeks). Median cost was similar for both groups (Amplatzer pound5375, surgical pound5412). CONCLUSIONS: Amplatzer ASD closure has a lower chance of success with a single procedure than surgery. Overall, there were more complications in the surgical group but the majority of these were minor and did not require any change in management. Resolution of right ventricular dilatation over the study period was similar for both techniques. Time spent in hospital and away from work or school was shorter for the Amplatzer group. The cost of both techniques was similar.