Long-term astigmatism after intraocular pressure sensor implantation and nonpenetrating glaucoma surgery: EYEMATE-SC trial.

PURPOSE: To investigate long-term astigmatism after combined nonpenetrating glaucoma surgery (NPGS) and implantation of the first miniaturized suprachoroidal intraocular pressure (IOP) sensor EYEMATE-SC. SETTING: The study was conducted in 5 medical centers in 2 different countries. DESIGN: Retrospective multicenter clinical study. METHODS: Astigmatism of patients instrumented with the EYEMATE-SC IOP sensor was assessed over a follow-up period of 3 years. Refraction and corrected distance visual acuity (CDVA) were obtained preoperatively, after 6 months, 1, 2, and 3 years. A canaloplasty-operated patient cohort served as control. Astigmatism was evaluated using 3-dimensional power vector analysis involving the spherical equivalent M, and the Jackson crossed cylinder projections J 0 and J 45 . Exclusion criteria included neovascular and angle-closure glaucoma, myopia, axial length outside 22 to 26 mm, other ocular diseases, prior glaucoma surgery, other ocular surgery within 6 months (cataract surgery within 3 months) before NPGS, serious generalized conditions, and other active medical head/neck implants. RESULTS: Multivariate analysis indicated no changes in astigmatism along the observation period in both the EYEMATE-SC (n = 24) and the canaloplasty (n = 24) group ( P > .05 or nonsignificant after Bonferroni correction). Astigmatism was unchanged between the EYEMATE-SC and the canaloplasty group at all timepoints ( P > .05). CDVA did not change along the observation period of 3 years in each of both groups ( P > .05). CONCLUSIONS: Despite its suprachoroidal localization, this study indicated that the miniaturized EYEMATE-SC IOP sensor did not negatively affect long-term astigmatism after combined implantation with NPGS.

Errors in pressure measurements due to changes in pressure transducer levels during adult cardiac surgery: a prospective observational study.

BACKGROUND: Blood pressure measurement is an essential element during intraoperative patient management. However, errors caused by changes in transducer levels can occur during surgery. METHODS: This single center, prospective, observational study enrolled 25 consecutive patients scheduled for elective cardiac surgery with invasive arterial and central venous pressure (CVP) monitoring. Hydrostatic pressures caused by level differences (leveling pressure) between a reference point (on the center of the left biceps brachii muscle) and the transducers (fixed on the right side of the operating table) for arterial and central lines were continuously measured using a leveling transducer. Adjusted pressures were calculated as measured pressure - leveling pressure. Hypotension (mean arterial pressure < 80, <70, and < 60 mmHg), and CVP (< 6, ≥6 and < 15, or ≥ 15 mmHg) and pulmonary artery pressure (PAP, mean > 20 mmHg) levels were determined using unadjusted and adjusted pressures. RESULTS: Twenty-two patients were included in the analysis. Leveling pressure ≥ 3 mmHg and ≥ 5 mmHg observed at 46.0 and 18.7% of pooled data points, respectively. Determinations of hypotension using unadjusted and adjusted pressures showed disagreements ranging from 3.3 to 9.4% depending on the cutoffs. Disagreements in defined levels of CVP and PAP were observed at 23.0 and 17.2% of the data points, respectively. CONCLUSIONS: The errors in pressure measurement due to changes in transducer level were not trivial and caused variable disagreements in the determination of MAP, CVP, and PAP levels. To prevent distortions in intraoperative hemodynamic management, strategies should be sought to minimize or adjust for these errors in clinical practice. TRIAL REGISTRATION: cris.nih.go.kr (KCT0006510).

A Multimodal Sensory Apparatus for Robotic Prosthetic Feet Combining Optoelectronic Pressure Transducers and IMU.

Timely and reliable identification of control phases is functional to the control of a powered robotic lower-limb prosthesis. This study presents a commercial energy-store-and-release foot prosthesis instrumented with a multimodal sensory system comprising optoelectronic pressure sensors (PS) and IMU. The performance was verified with eight healthy participants, comparing signals processed by two different algorithms, based on PS and IMU, respectively, for real-time detection of heel strike (HS) and toe-off (TO) events and an estimate of relevant biomechanical variables such as vertical ground reaction force (vGRF) and center of pressure along the sagittal axis (CoPy). The performance of both algorithms was benchmarked against a force platform and a marker-based stereophotogrammetric motion capture system. HS and TO were estimated with a time error lower than 0.100 s for both the algorithms, sufficient for the control of a lower-limb robotic prosthesis. Finally, the CoPy computed from the PS showed a Pearson correlation coefficient of 0.97 (0.02) with the same variable computed through the force platform.

Resuscitative endovascular balloon occlusion of the aorta management guided by a novel handheld pressure transducer.

BACKGROUND: Management of noncompressible truncal hemorrhage using resuscitative endovascular balloon occlusion of the aorta (REBOA) requires arterial pressure monitoring that can be logistically challenging in austere or emergency settings. Novel pressure transducer devices such as the Centurion Compass device (CD) (Medline, Northfield, IL) offer an alternative to traditional monitoring systems. We sought to assess the feasibility of maintaining permissive hypotension during intermittent REBOA in a porcine model guided by CD monitoring. METHODS: Eight Yorkshire swine underwent 20% hemorrhage with an uncontrolled iliofemoral vascular injury. Time-based intermittent zone 1 REBOA was performed with volume-based resuscitation to maintain permissive hypotension. Proximal mean arterial pressures (MAPs) from a carotid arterial line (AL) were obtained and compared with CD readings from the proximal REBOA port. The operator was blinded to AL MAP, and the REBOA was managed with exclusively the CD. RESULTS: Mean survival time was 100 minutes (range, 41-120 minutes) from injury. Arterial line and CD measurements were closely correlated (r = 0.94, p < 0.001). Bland-Altman analysis for comparison of clinical measurements demonstrated a mean difference of 6 mm Hg (95% confidence interval, -22 to 34 mm Hg) for all MAPs, with a mean difference of 3 mm Hg (95% confidence interval, -6 to 12 mm Hg) in a clinically relevant MAP of <65 mm Hg subset. CONCLUSION: The CD represents a miniaturized and portable arterial pressure monitor that provides an accurate alternative to logistically burdensome AL monitoring to guide REBOA use. The device is highly accurate even at hypotensive pressures and can be used to guide intermittent REBOA strategies.

Insights from intravascular pressure measurement of renal artery revascularization in patients with fibromuscular dysplasia: The DYSART study.

OBJECTIVE: The indication of percutaneous renal transluminal angioplasty (PTRA) in fibromuscular dysplasia (FMD) is mainly based on renal artery stenosis (RAS) due to atherosclerosis criteria, which are not specific to FMD. Consequently, the selection of patients who could benefit from this treatment and its effectiveness remain uncertain. The aims of this study were to: (1) report the effects of PTRA guided by trans-stenotic pressure measurements on hypertension 7 months after treatment; (2) assess the impact of pressure measurement to guide treatment efficacy in comparison to visual angiographic parameters; and (3) evaluate the reproducibility and accuracy of the stenosis measurement using a 4F catheter in comparison to a pressure guidewire. METHODS: This prospective multi-centric study analyzed 24 patients with hypertension with RAS due to FMD that required PTRA. Clinical, duplex ultrasound, and angiographic indices were collected, and patients were followed up for 7 months (±1 month). Angiographic indices were measured twice both by a pressure guidewire and a 4F catheter. Assessment of procedural and clinical success of angioplasty was performed for all patients. RESULTS: Twenty-three patients (96%) had procedural success (considered as a post-PTRA translesional systolic gradient ≤10 mmHg or reduced by at least 80%) with a significant decrease in the systolic gradient after angioplasty (26.50 mmHg; [interquartile range, 16.75-38.75] vs 0.00 [interquartile range, 0.00-2.00]; P < .01). Three patients (12%) had complications, including two renal artery dissections and one partial renal infarction. Twenty-one patients (88%) were clinical responders to angioplasty at follow-up. Visual stenosis assessment showed a poor correlation with systolic gradient measurement before and after PTRA (R from -0.05 to 0.41; P = 0.06-0.82). High correlations were found between pressure measurements made by a 4F catheter and guidewire (R from 0.64 to 0.89; P ≤ .003). CONCLUSIONS: In patients selected by clinical indicators and duplex ultrasound, reaching a translesional systolic gradient ≤10 mmHg or reduced by at least 80% after angioplasty, promotes a high success rate for PTRA in hypertension due to FMD RAS.

Treatment of posterolateral tibial plateau fractures with a rotational support plate and special pressurizer: technical note and retrospective case series.

BACKGROUND: In tibial plateau fractures, the posterolateral segment of the tibia plateau is frequently affected and challenging to treat. Although there are many surgical approaches and fixation methods for the treatment of these fractures, all of these methods have limitations. We designed a new rotational support plate (RSP) and a special pressurizer that can fix the fracture directly via the anterolateral approach. This method is advantageous because it leads to little trauma, involves a simple operation, and has a reliable fixation effect. This study details the technique of treating these fractures with the RSP and special pressurizer and provides the outcomes. METHODS: From May 2016 to January 2019, the data of 12 patients with posterolateral tibial plateau fractures treated with the RSP and special pressurizer in our hospital were retrospectively analyzed. Postoperative rehabilitation was advised, knee X-rays were taken at follow-ups, and fracture healing, complications, and knee range of motion were assessed. The Hospital for Special Surgery (HSS) knee score and Knee Injury and Osteoarthritis Outcome Score (KOOS) were used to evaluate knee function at the last follow-up. RESULTS: The average follow-up time of all patients was 16.5 months (range, 12-25 months). The average bony union time was 3.2 months (range, 3-4.5 months). At the last follow-up, the average knee range of motion was 138° (range, 107-145°). The average HSS score was 91 (range, 64-98). The average KOOS Symptoms score was 90 (range, 75-96). The average KOOS Pain score was 91 (range, 72-97). The average KOOS ADL score was 91 (range, 74-97). The average KOOS sport/recreation score was 83 (range, 70-90). The average KOOS QOL score was 88 (range, 69-93). Skin necrosis, incision infections, and fixation failure did not occur during the follow-up period. CONCLUSIONS: With our newly designed RSP and special pressurizer, posterolateral tibial plateau fractures can be easily and effectively reduced and fixed through the anterolateral approach, which serves as a novel treatment for posterolateral tibial plateau fractures.

Good urodynamic practice: Pressure signal quality immediately after catheter insertion for cystometry with a water-filled pressure transducer system and its relevance for the ICS zero procedure.

AIM: This study aims to evaluate the intracorporeal pressures immediately after the insertion of the catheters for urodynamic testing with a water-filled urodynamic pressure transducer system to determine the relevance of the International Continence Society (ICS) zeroing principles. METHODS: Here, a retrospective analysis of a random series of urodynamic recordings is performed. The initial pressures, immediately after the insertion of the catheters, have been compared with the pressures after some milliliters of filling and flushing away of the gel, used with insertion, and/or the mucus and debris from the inserted catheters. Differences of initially recorded intravesical and intrarectal pressures from those after flushing and filling are analyzed and associated with the ICS standard practice of zeroing. RESULTS: Statistically and clinically significant differences between the initial pressures and the pressures after filling and flushing are observed, with nonphysiological initial pressures in 62% of the studies. Some filling (20 ml or more in the bladder) and flushing of the pressure channels resulted in the registration of physiological pressures and synchronous response from both lines on abdominal pressure increases. CONCLUSIONS: The pressure signal quality of a water-filled urodynamic system immediately after catheter insertion is low with inaccurately displayed pressure values, but it changes to normal after flushing the pressure channels and some filling. Rezeroing of the intracorporeal pressures immediately after catheter insertion for cystometry is the inappropriate correction procedure that misleadingly modifies the false initial pressures, resulting in ongoing unrealistic urodynamic study pressures.

Measurement of airway pressure during high-flow nasal therapy in apnoeic oxygenation: a randomised controlled crossover trial.

It is recognised that high-flow nasal therapy can prevent desaturation during airway management. Studies in spontaneously breathing patients show an almost linear relationship between flow rate and positive airway pressure in the nasopharynx. Positive airway pressure has been suggested as one of the possible mechanisms explaining how high-flow nasal therapy works. However, data on pressures generated by high-flow nasal therapy in apnoeic adults under general anaesthesia are absent. This randomised controlled crossover trial investigated airway pressures generated by different flow rates during high-flow nasal therapy in anaesthetised and paralysed apnoeic patients, comparing pressures with closed and open mouths. Following induction of anaesthesia and neuromuscular blockade, a continuous jaw thrust was used to enable airway patency. Airway pressure was measured in the right main bronchus, the middle of the trachea and the pharynx, using a fibreoptically-placed catheter connected to a pressure transducer. Each measurement was randomised with respect to closed or open mouth and different flow rates. Twenty patients undergoing elective surgery were included (mean (SD) age 38 (18) years, BMI 25.0 (3.3) kg.m-2 , nine women, ASA physical status 1 (35%), 2 (55%), 3 (10%). While closed mouths and increasing flow rates demonstrated non-linear increases in pressure, the pressure increase was negligible with an open mouth. Airway pressures remained below 10 cmH2 O even with closed mouths and flow rates up to 80 l.min-1 ; they were not influenced by catheter position. This study shows an increase in airway pressures with closed mouths that depends on flow rate. The generated pressure is negligible with an open mouth. These data question positive airway pressure as an important mechanism for maintenance of oxygenation during apnoea.

A Novel Aortic Regurgitation Model from Cusp Prolapse with Hemodynamic Validation Using an Ex Vivo Left Heart Simulator.

Although ex vivo simulation is a valuable tool for surgical optimization, a disease model that mimics human aortic regurgitation (AR) from cusp prolapse is needed to accurately examine valve biomechanics. To simulate AR, four porcine aortic valves were explanted, and the commissure between the two largest leaflets was detached and re-implanted 5 mm lower to induce cusp prolapse. Four additional valves were tested in their native state as controls. All valves were tested in a heart simulator while hemodynamics, high-speed videography, and echocardiography data were collected. Our AR model successfully reproduced cusp prolapse with significant increase in regurgitant volume compared with that of the controls (23.2 ± 8.9 versus 2.8 ± 1.6 ml, p = 0.017). Hemodynamics data confirmed the simulation of physiologic disease conditions. Echocardiography and color flow mapping demonstrated the presence of mild to moderate eccentric regurgitation in our AR model. This novel AR model has enormous potential in the evaluation of valve biomechanics and surgical repair techniques. Graphical Abstract.

A Comparison of the Required Bronchial Cuff Volume Obtained by 2 Cuff Inflation Methods, Capnogram Waveform-Guided Versus Pressure-Guided: A Prospective Randomized Controlled Study.

BACKGROUND: Double-lumen endobronchial tubes (DLTs) are used for one-lung ventilation (OLV) during thoracic surgery. Overinflation into the bronchial cuff causes damage to the tracheobronchial mucosa, whereas underinflation leads to an incomplete collapse of the nonventilated lung or incomplete ventilation of the ventilated lung. However, how to determine the appropriate bronchial cuff volume and pressure during OLV is unclear. The objective of this study is to compare the required bronchial cuff volume for lung separation obtained by 2 different cuff inflation methods under closed- and open-chest conditions. METHODS: A total of 64 patients scheduled to undergo elective thoracic surgery requiring OLV were recruited. Left DLTs were used for both right- and left-sided surgery. The patients were randomly assigned to 1 of 2 inflation-type groups to estimate the bronchial cuff volume. In the capnogram waveform-guided bronchial cuff inflation group (capno group, n = 27), the bronchial cuff was inflated until a capnometer sampling gas containing CO2 from the nonventilated lung displayed a flat line. The corresponding bronchial cuff volume and pressure were then recorded. In the pressure-guided bronchial cuff inflation group (pressure group, n = 29), the bronchial cuff was inflated by a cuff inflator to a pressure of 20 cm H2O. Lung separation was confirmed when a flat line of a capnometer was observed after gas sampling from the nonventilated lung. RESULTS: Under closed-chest conditions, the bronchial cuff sealing volume for the capno group was significantly lower than that for the pressure group (mean [standard deviation {SD}], 1.00 [0.65] mL vs 1.44 [0.59] mL, mean difference, -0.44; 97.5% confidence interval [CI], -0.78 to -0.11; P = .010). Under open-chest conditions, the bronchial cuff sealing volume for the capno group was also significantly lower than that for the pressure group (mean [SD], 0.65 [0.66] mL vs 1.22 [0.45] mL, mean difference, -0.58; 97.5% CI, -0.88 to -0.27; P < .001). CONCLUSIONS: The lowest cuff volume providing an air-tight bronchial seal was obtained by the capnogram waveform-guided bronchial cuff inflation method. Since the cuff volume required to achieve an air-tight seal decreases after opening the chest, readjustment of the bronchial cuff volume to prevent bronchial cuff damage to the tracheobronchial mucosa after opening the chest may be advisable.

Real-Time Injection Pressure Sensing and Minimal Intensity Stimulation Combination During Ultrasound-Guided Peripheral Nerve Blocks: An Exploratory Observational Trial.

BACKGROUND: Nerve damage can occur after peripheral nerve block (PNB). Ultrasound guidance does not eliminate the risk of intraneural injection or nerve injury. Combining nerve stimulation and injection pressure (IP) monitoring with ultrasound guidance has been suggested to optimize needle tip location in PNB. In this prospective observational study, we hypothesized that measured pairs of IP and minimum intensity of stimulation (MIS) might differentiate successive needle tip locations established by high-resolution ultrasound during PNB. METHODS: For this exploratory study, 240 observations for 40 ultrasound-guided PNBs were studied in 28 patients scheduled for orthopedic surgery. During the progression of the needle to the nerve observed by ultrasonography, the IP was measured continuously using a computerized pressure-sensing device with a low flow rate of solution. Stimulation thresholds and electrical impedance were obtained by an impedance analyzer coupled to the nerve stimulator at 6 successive needle positions. The median (quartile) or mean (95% confidence interval [CI]) was reported. A mixed model analysis was used, and the sample was also explored using a classification and regression tree (CART) algorithm. RESULTS: Specific combinations of IP and MIS were measured for subcutaneous, epimysium contact, intramuscular, nerve contact (231 mm Hg [203-259 mm Hg] and 1.70 mA [1.38-2.02 mA]), intraneural location (188 mm Hg [152-224 mm Hg] and 0.58 mA [0.46-0.70 mA]), and subparaneural location (47 mm Hg [41-53 mm Hg] and 1.35 mA [1.09-1.61 mA]). The CART algorithm shows that the optimal subparaneural needle tip position might be defined by the lowest pressure (<81.3 mm Hg) and MIS (<1.5 mA) cutoffs. CONCLUSIONS: Our exploratory study evaluated concepts to generate hypotheses. The combinations of IP and MIS might help the physician during a PNB procedure. A low IP and low MIS might confirm a subparaneural location, and a high IP and a low MIS might be an alert for the intraneural location of the needle tip.

Subchondral pressures and perfusion during weight bearing.

BACKGROUND: Joints withstand huge forces, but little is known about subchondral pressures and perfusion during loading. We developed an in vitro calf foot model to explore intraosseous pressure (IOP) and subchondral perfusion during weight bearing. METHODS: Freshly culled calf forefeet were perfused with serum. IOP was measured at three sites in the foot using intraosseous needles, pressure transducers, and digital recorders. IOP was measured during perfusion, with and without a tourniquet and with differing weights, including static loading and dynamic loading to resemble walking. RESULTS: IOP varied with perfusion pressure. Static loading increased subchondral IOP whether the bone was non-perfused, perfused, or perfused with a proximal venous tourniquet (p < 0.0001). Under all perfusion states, IOP was proportional to the load (R2 = 0.984). Subchondral IOP often exceeded perfusion pressure. On removal of a load, IOP fell to below the pre-load value. Repetitive loading led to a falling IOP whether the foot was perfused or not. CONCLUSION: Superimposed on a variable background IOP, increased perfusion and physiological loading caused a significant increase in subchondral IOP. Force was thereby transmitted through subchondral bone partly by hydraulic pressure. A falling IOP with repeat loading suggests that there is an intraosseous one-way valve. This offers a new understanding of subchondral perfusion physiology.

Esophageal Functional Lumen Imaging Probe (FLIP): How Can FLIP Enhance Your Clinical Practice?

Recent innovations in esophageal diagnostic testing have enhanced gastroenterology clinical practice by facilitating more nuanced and advanced evaluation of esophageal symptoms. Among these pivotal advances is the FDA-approved functional lumen imaging probe (FLIP), which utilizes impedance planimetry via volumetric distension of a catheter-mounted balloon at the time of sedated upper endoscopy, to acquire esophageal dimensions and pressures. In real time, FLIP can display cross-sectional areas (CSA) and distensibility indices (ratios of CSA to intra-balloon pressures) throughout the esophagus, most notably at the esophagogastric junction, as well as secondary peristaltic esophageal body contractile patterns. As the use of FLIP has progressively spread and permeated into the practice of clinical gastroenterology since its introduction, increasing data on and experiences with its applications have accumulated to guide its utility in clinical practice. In this current review developed for gastroenterologists and foregut surgeons across clinical practice, we provide an introduction to FLIP technology and metrics and discuss the clinical scenarios in which performance of or referral for FLIP may be helpful in the evaluation and management of patients with commonly encountered esophageal symptoms and disorders. Specifically, we discuss the potential applications and limitations of FLIP as a complementary diagnostic modality in patients with non-obstructive dysphagia, established or suspected achalasia spectrum disorders, eosinophilic esophagitis, gastroesophageal reflux disease and those undergoing esophageal surgery.

A Noninvasive Assistant System in Diagnosis of Lumbar Disc Herniation.

The purpose of this study is the application of pressure sensors in diagnostics and evaluation of the accuracy diagnostics of lumbar disc herniation at levels L4/L5 and L5/S1 using the aforementioned platform. The motivation behind the idea to apply the pressure measurement platform is the fact that the motor weakness of plantar and dorsal flexia of the feet is one of the absolute indications for the operative treatment of patients with lumbar disc herniation at the indicated levels. In patients, MRI diagnosis of the lumbosacral spine served as the ground truth in the diagnosis of herniation at L4/L5 and L5/S1 levels. The inclusive criteria for the study were the proven muscle weakness based on manual muscle tests performed prior to surgery, after seven days of surgery and after physical therapy. The results obtained with the manual muscular test were compared with the results obtained using our platform. The study included 33 patients who met the inclusion criteria. The results of the measurements indicate that the application of our platform with pressure sensors has the same sensitivity diagnostics as a manual muscle test, when done preoperatively and postoperatively. After physical therapy, pressure sensors show statistically significantly better sensitivity compared to the clinical manual muscle test. The obtained results are encouraging in the sense that the pressure platform can be an additional diagnostic method for lumbar disc herniation detection and can indicate the effectiveness of operative treatment and physical therapy after operation. The main advantage of the system is the cost; the whole system with platform and sensors is not expensive.

Novel Indices of Coronary Physiology: Do We Need Alternatives to Fractional Flow Reserve?

Fractional flow reserve is the current invasive gold standard for assessing the ischemic potential of an angiographically intermediate coronary stenosis. Procedural cost and time, the need for coronary vessel instrumentation, and the need to administer adenosine to achieve maximal hyperemia remain integral components of invasive fractional flow reserve. The number of new alternatives to fractional flow reserve has proliferated over the last ten years using techniques ranging from alternative pressure wire metrics to anatomic simulation via angiography or intravascular imaging. This review article provides a critical description of the currently available or under-development alternatives to fractional flow reserve with a special focus on the available evidence, pros, and cons for each with a view towards their clinical application in the near future for the functional assessment of coronary artery disease.

Benefit of Contact Force-Guided Catheter Ablation for Treating Premature Ventricular Contractions.

We evaluated whether an irrigated contact force-sensing catheter would improve the safety and effectiveness of radiofrequency ablation of premature ventricular contractions originating from the right ventricular outflow tract. We retrospectively reviewed the charts of patients with symptomatic premature ventricular contractions who underwent ablation with a contact force-sensing catheter (56 patients, SmartTouch) or conventional catheter (59 patients, ThermoCool) at our hospital from August 2013 through December 2015. During a mean follow-up of 16 ± 5 months, 3 patients in the conventional group had recurrences, compared with none in the contact force group. Complications occurred only in the conventional group (one steam pop; 2 ablations suspended because of significantly increasing impedance). In the contact force group, the median contact force during ablation was 10 g (interquartile range, 7-14 g). Times for overall procedure (36.9 ± 5 min), fluoroscopy (86.3 ± 22.7 s), and ablation (60.3 ± 21.4 s) were significantly shorter in the contact force group than in the conventional group (46.2 ± 6.2 min, 107.7 ± 30 s, and 88.7 ± 32.3 s, respectively; P <0.001). In the contact force group, cases with a force-time integral <560 gram-seconds (g-s) had significantly longer procedure and fluoroscopy times (both P <0.001) than did those with a force-time integral ≥560 g-s. These findings suggest that ablation of premature ventricular contractions originating from the right ventricular outflow tract with an irrigated contact force-sensing catheter instead of a conventional catheter shortens overall procedure, fluoroscopy, and ablation times without increasing risk of recurrence or complications.

Correlation Between Doppler Derived Carotid Artery Corrected Flow Time and Pressure Transducer Derived Radial Artery Corrected Flow Time: A Prospective Observational Study.

PURPOSE: Carotid artery corrected flow time (cFT) derived from Doppler USG is a known predictor of volume responsiveness. However, it can't be obtained continuously, and is operator dependent. In this prospective study, correlation between Doppler derived carotid artery cFT and pressure transducer derived radial artery cFT was evaluated in adult patients undergoing surgery under general anaesthesia. METHODS: Doppler derived carotid artery cFT were obtained from n = 51 adult patients at n = 125 time points. Simultaneously, pressure transducer waveforms were saved at the time of measurement of carotid artery cFT. Later, images were analyzed by an image processing computer software; both pulse pressure variation and cFT were estimated from pressure transducer waveform. RESULTS: Radial artery flow times measured by two independent observers, were significantly correlated (r2 = 0.99, p < 0.00001). Bland-Altman analysis found limits of agreement - 8.3 to 6.3 ms [mean difference (95% CI) - 0.98 (- 1.63, - 0.32)]. Doppler derived carotid artery cFT & pressure transducer derived radial artery cFT were also significantly correlated [r2 = 0.78, p < 0.0001]. However, radial artery cFT was significantly higher than carotid artery cFT [p < 0.0001, paired sample t test]. Radial artery cFT > 404.4 ms had an sensitivity and specificity of 87.34% and 85% respectively with a grey zone was between 393.7 and 417 ms to predict PPV ≥ 12%. CONCLUSION: Pressure transducer derived radial artery cFT correlated with Doppler derived carotid artery cFT and may be a reasonable predictor of volume responsiveness. Further studies are required to confirm its role in various clinical scenario for prediction of volume responsiveness.

Safety and efficacy of the ThermoCool SmartTouch SurroundFlow catheter for atrial fibrillation ablation: A meta-analysis.

BACKGROUND: The ThermoCool Smarttouch Surroundflow catheter (STSFc) is an advanced catheter, which integrating contact force sensing and surroundflow technology. However, comparative data between STSFc and contact force sensing catheter (Thermocool SmartTouch catheter [STc]) are limited. HYPOTHESIS: We thought that STSFc might bring more clinical benefits. The aim of this meta-analysis was to compare the safety and efficiency between the STSFc and the STc for treatment of atrial fibrillation (AF). METHODS: The Medline, PubMed, Embase, and Cochrane Library databases were searched for studies comparing STSFc and STc. RESULTS: Four trials involving 727 patients were included in the study. Pool-analyses demonstrated that, as compared STc ablation, STSFc ablation was more beneficial in terms of procedural times (standard mean difference [SMD]: -0.22; 95% confidence interval [CI], -0.37 to -0.07, P = .005) and irrigation fluid volume (SMD: -1.94; 95% CI, -2.65 to -1.22, P < .0001). There was no significant difference between STSFc and STc (risk ratio [RR]: 1.02; 95% CI: 0.86 to 1.21, P = .79) for free from AF. Evidence of complications were low and similar for both groups (RR: 0.83; 95% CI: 0.19-3.55, P = .80). Additionally, patients administered STSFc ablation tended to have shorter fluoroscopic times (SMD: -0.20; 95% CI, -0.63-0.23, P = .21). CONCLUSIONS: STSFc ablation was associated with reducing procedural times and irrigation fluid volume. Further, STSFc ablation tended to shorten fluoroscopic times. Therefore, STSFc ablation would be a better choice for AF patients especially in patients with heart failure.

Porous tip contact force-sensing catheters for pulmonary vein isolation: performance in a clinical routine setting.

PURPOSE: In catheter ablation of atrial fibrillation (AF), contact force (CF)-sensing catheters with an irrigated tip are used to deliver radiofrequency (RF) energy to the tissue. The ThermoCool® Smarttouch™ Surroundflow catheter (STSF) integrates CF-sensing technology and a new porous tip for advanced external cooling. The aim was to evaluate the performance and safety of STSF in a clinical setting of pulmonary vein isolation (PVI) in comparison with standard contact force-sensing catheter (ST). METHODS: We assigned consecutive patients (n = 80, prospectively, open-label, non-randomized) with symptomatic AF to either PVI with STSF (n = 60) or ST (n = 20). RESULTS: Total ablation time to achieve PVI was significantly shorter in STSF compared to that in ST (STSF, 1556 ± 435 s vs. ST, 1922 ± 961 s; p = 0.045). Ablation time to achieve loss of pace capture of left pulmonary veins was shorter using STSF (left veins, 155 ± 140 s vs. 291 ± 188 s; p = 0.01; right veins, 208 ± 196 s vs. 369 ± 306 s; p = 0.09). Furthermore, administered irrigation fluid was significantly reduced in STSF (241.4 ± 79.6 ml vs. 540.3 ± 229.5 ml; p < 0.01). CF was lower during ablation of left pulmonary veins. One steam pop occurred in STSF, which did not lead to pericardial effusion (vs. no steam pop in ST). The Kaplan-Meier estimate 12-month AF recurrence was 34.3% and 37.7% (p = 0.8). CONCLUSIONS: Integrating CF technology and the porous tip technology enables effective energy transfer to the tissue resulting in shorter ablation time and less irrigation fluid administration. In our cohort, PVI using the STSF was not associated with an increased complication rate or AF recurrence rate after 12-month follow-up when compared with the ST.