Pressure Guidewire Research Articles

Serial manual bolus irrigation leads to critical intrarenal pressures during flexible ureterorenoscopy - time to abandon this manoeuvre.

To characterise the effect of solitary and serial manual bolus irrigations on intrarenal pressures (IRPs) and observe the clinical consequences. A pressure guidewire was used for IRP measurement during routine flexible ureterorenoscopy for management of renal stone disease, including manual bolus irrigation when required to maintain vision. The fluid bolus was either as a solitary manual bolus or a series of manual boluses in quick succession. The pre-bolus, maximal and difference between IRPs were calculated. A total of 50 procedures in 46 patients were analysed. In all, 68 solitary manual boluses and 38 serial manual boluses were observed to have been undertaken during these procedures. After a solitary manual bolus, the median (standard deviation [SD], range) increase in IRP was 22.4 (34.0, 0.1-160.8) mmHg, and the mean (SD, range) maximum IRP was 46.1 (41.7, 15.8-190.0) mmHg, with elevated IRPs persisting for a median (range) duration of 19 (4-66) s. After serial manual boluses, the median (SD, range) rise in IRP was 58.4 (64.7, 10.2-242.84) mmHg and the mean (SD, range) maximum IRP reached was 100.8 (69.7, 34.3-303.5) mmHg. The elevated IRPs endured for a median (range) of 42 (9-121 s; P < 0.01 in all comparisons), suggesting a much greater elevation of IRP with instances where serial bolus irrigation was undertaken. Manual bolus irrigation, both solitary but particularly serial boluses, produces significant rises in IRP and could logically result in pyelovenous backflow and sepsis. We suggest that this manoeuvre should be avoided to reduce complications during ureterorenoscopy.

Human in vivo baseline intrarenal pressure, peristaltic activity and response to ureteric stenting.

To assess human in vivo intrarenal pressure (IRP) and peristaltic activity at baseline and after ureteric stent placement, using a narrow calibre pressure guidewire placed retrogradely in the renal pelvis. A prospective, multi-institutional study recruiting consenting patients undergoing ureteroscopy was designed with ethical approval. Prior to ureteroscopy, the urinary bladder was emptied and the COMET™ II pressure guidewire (Boston Scientific) was advanced retrogradely via the ureteric orifice to the renal pelvis. Baseline IRPs were recorded for 1-2 min. At procedure completion, following ureteric stent insertion, IRPs were recorded for another 1-2 min. Statistical analysis of mean baseline IRP, peristaltic waveforms and frequency of peristaltic contractions was performed, thereby analysing the influence of patient variables and ureteric stenting. A total of 100 patients were included. Baseline mean (±SD) IRP was 16.76 (6.4) mmHg in the renal pelvis, with maximum peristaltic IRP peaks reaching a mean (SD) of 25.75 (17.9) mmHg. Peristaltic activity generally occurred in a rhythmic, coordinated fashion, with a mean (SD) interval of 5.63 (3.08) s between peaks. On univariate analysis, higher baseline IRP was observed with male sex, preoperative hydronephrosis, and preoperative ureteric stenting. On linear regression, male sex was no longer statistically significant, whilst the latter two variables remained significant (P = 0.004; P < 0.001). The mean (SD) baseline IRP in the non-hydronephrotic, unstented cohort was 14.19 (4.39) mmHg. Age, α-blockers and calcium channel blockers did not significantly influence IRP, and no measured variables influenced peristaltic activity. Immediately after ureteric stent insertion, IRP decreased (mean [SD] 15.18 [5.28] vs 16.76 [6.4] mmHg, P = 0.004), whilst peristaltic activity was maintained. Human in vivo mean (SD) baseline IRP is 14.19 (4.39) mmHg in normal kidneys and increases with both hydronephrosis and preoperative ureteric stenting. Mean (SD) peristaltic peak IRP values of 25.75 (17.9) mmHg are reached in the renal pelvis every 3-7 s and maintained in the early post-stent period.

Offline Assessment of the Quantitative Flow Ratio: Is it Useful in Clinical Practice?

Fractional flow reserve (FFR) has been established as the gold standard in the physiological assessment of coronary obstructions severity. However, the need to insert an intracoronary pressure guidewire is a factor that limits its use. Quantitative flow ratio (QFR) is a method that infers the value of FFR from 3-dimensional quantitative coronary angiography (3D-QCA), eliminating the use of a pressure wire and coronary hyperemia. The present study aims to evaluate the diagnostic accuracy of QFR and 3D-QCA in comparison with FFR for the identification of significant obstructive coronary lesions (FFR ≤.80) and the feasibility to assess QFR in a cohort of patients without dedicated angiographic acquisition. Consecutive patients with coronary angiography with moderate obstructive lesions that had previous FFR measurement were evaluated. Validation of QFR was assessed by the area under the curve (AUC) and other statistical tools, using FFR as the reference method. Seventy-five arteries from 69 patients were evaluated. The accuracy of the QFR to detect FFR ≤.80 was 84.0% (95% confidence interval, 75.6-92.4). The correlation and agreement between FFR and QFR were r=0.54 (P<.01) and mean difference was -0.02 ± 0.09 (P=.09), respectively. The AUC of QFR and 3D-QCA identifying stenosis >50% was 0.854 and 0.755, respectively (P=.09). QFR demonstrated good accuracy compared with FFR for the assessment of moderate obstructive coronary lesions in an unselected clinical practice population. However, many patients were excluded from the analysis and there was no statistical difference between the receiver operator characteristic curves of the QFR and percent diameter stenosis.

Intrarenal pressure with hand-pump or pressurized-bag irrigation: randomized clinical trial at retrograde intrarenal surgery.

The aim was to ascertain the impact of irrigation technique on human intrarenal pressure during retrograde intrarenal surgery. A parallel randomized trial recruited patients across three hospital sites. Patients undergoing retrograde intrarenal surgery for renal stone treatment with an 11/13-Fr ureteral access sheath were allocated randomly to 100 mmHg pressurized-bag (PB) or manual hand-pump (HP) irrigation. The primary outcome was mean procedural intrarenal pressure. Secondary outcomes included maximum intrarenal pressure, variance, visualization, HP force of usage, procedure duration, stone clearance, and clinical outcomes. Live intrarenal pressure monitoring was performed using a COMETTMII pressure guidewire, deployed cystoscopically to the renal pelvis. The operating team was blinded to the intrarenal pressure. Thirty-eight patients were randomized between July and November 2023 (trial closure). The final analysis included 34 patients (PB 16; HP 18). Compared with PB irrigation, HP irrigation resulted in significantly higher mean intrarenal pressure (mean(s.d.) 62.29(27.45) versus 38.16(16.84) mmHg; 95% c.i. for difference in means (MD) 7.97 to 40.29 mmHg; P = 0.005) and maximum intrarenal pressure (192.71(106.23) versus 68.04(24.16) mmHg; 95% c.i. for MD 70.76 to 178.59 mmHg; P < 0.001), along with greater variance in intrarenal pressure (log transformed) (6.23(1.59) versus 4.60(1.30); 95% c.i. for MD 0.62 to 2.66; P = 0.001). Surgeon satisfaction with procedural vision reported on a scale of 10 was higher with PB compared with HP irrigation (mean(s.d.) 8.75(0.58) versus 6.28(1.27); 95% c.i. for MD 1.79 to 3.16; P < 0.001). Subjective HP usage force did not correlate significantly with transmitted intrarenal pressure (Pearson R = -0.15, P = 0.57). One patient (HP arm) developed urosepsis. Manual HP irrigation resulted in higher and more fluctuant intrarenal pressure trace (with inferior visual clarity) than 100-mmHg PB irrigation. osf.io/jmg2h (https://osf.io/).

Correlations between intravascular pressure gradients and cerebral blood flow in patients with symptomatic, medically refractory, anterior circulation artery stenosis: an exploratory study

BackgroundFractional flow reserve is widely used in coronary disease management, with a threshold of 0.80. However, similar thresholds are unclear in functional assessment of intracranial atherosclerotic stenosis (ICAS).ObjectiveTo investigate the...

Fluid-filled versus sensor-tipped pressure guidewires for FFR and Pd/Pa measurement; PW-COMPARE study

BackgroundFluid-filled pressure guidewires are unaffected by the previously inevitable hydrostatic pressure gradient (HPG). This study aimed to compare simultaneous pressure measurements with fluid-filled and sensor-tipped pressure guidewires. MethodsFifty patients underwent fractional flow reserve (FFR) and Pd/Pa measurement with a fluid-filled and a sensor-tipped pressure guidewire simultaneously. To assess maneuverability, patients were randomized with respect to which pressure guidewire was used to cross the lesion first. Lateral fluoroscopy was used to estimate height difference between catheter tip and distal wire position (and thus HPG). Agreement between pressure measurements was studied. ResultsMeasurements were performed in LM (4% (n = 2)), LAD (44% (n = 22)), LCX (26% (n = 13)), and RCA (26% (n = 13)). Simultaneous pressure measurements showed excellent agreement (mean FFR difference − 0.01 ± 0.03 (r = 0.959, p < 0.001), mean Pd/Pa difference − 0.01 ± 0.04 (r = 0.929, p < 0.001)). FFR was ≤0.80 in 42.6% (n = 20) with fluid-filled FFR measurements versus 46.8% (n = 22) by sensor-tipped FFR measurements. Mean height difference was 15 ± 34 mm, and strongly dependent on the coronary artery (LAD 45 ± 10 mm, LCX −23 ± 16 mm, RCA −13 ± 17 mm). There was a strong correlation between height difference and difference in pressure ratios between sensor-tipped and fluid-filled pressure guidewires (FFR r = −0.850, p < 0.001; Pd/Par = −0.641, p < 0.001). Largest FFR differences were present in the LAD (−0.04 ± 0.02). After HPG correction, mean difference between HPG-corrected sensor-tipped FFR and fluid-filled FFR was 0.00 ± 0.02, mean Pd/Pa difference was 0.01 ± 0.03. ConclusionsThis study shows excellent overall correlation between FFR and Pd/Pa measurements with both pressure guidewires. Differences measured with fluid-filled and sensor-tipped pressure guidewires are vessel-specific and attributable to hydrostatic pressure gradients (NCT04802681).

Impact of Pressure Guidewire on Model-Based FFR Prediction

IntroductionFractional Flow Reserve (FFR) is used to characterize the functional significance of coronary artery stenoses. FFR is assessed under hyperemic conditions by invasive measurements of trans-stenotic pressure thanks to the insertion of a pressure guidewire across the coronary stenosis during catheterization. In order to overcome the potential risk related to the invasive procedure and to reduce the associated high costs, three-dimensional blood flow simulations that incorporate clinical imaging and patient-specific characteristics have been proposed.PurposeMost CCTA-derived FFR models neglect the potential influence of the guidewire on computed flow and pressure. Here we aim to quantify the impact of taking into account the presence of the guidewire in model-based FFR prediction.MethodsWe adopt a CCTA-derived FFR model and perform simulations with and without the guidewire for 18 patients with suspected stable CAD.ResultsPresented results show that the presence of the guidewire leads to a tendency to predict a lower FFR value. The FFR reduction is prominent in cases of severe stenoses, while the influence of the guidewire is less pronounced in cases of moderate stenoses.ConclusionFrom a clinical decision-making point of view, including of the pressure guidewire is potentially relevant only for intermediate stenosis cases.

Diagnostic Performance of Angiography-Derived Quantitative Flow Ratio in Complex Coronary Lesions.

Quantitative flow ratio derived from computed tomography angiography (CT-QFR) and invasive coronary angiography (Murray law-based quantitative flow ratio [μQFR]) are novel approaches enabling rapid computation of fractional flow reserve without the use of pressure guidewires and vasodilators. However, the feasibility and diagnostic performance of both CT-QFR and μQFR in evaluating complex coronary lesions remain unclear. Between September 2014 and September 2021, 240 patients with 30% to 90% coronary diameter stenosis who underwent both coronary computed tomography angiography and invasive coronary angiography with fractional flow reserve within 60 days were retrospectively enrolled. The diagnostic performance of CT-QFR and μQFR in detecting functional ischemia among all lesions, especially complex coronary lesions, was analyzed using fractional flow reserve as the reference standard. CT-QFR and μQFR analyses were performed on 309 and 289 vessels, respectively. The diagnostic sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for CT-QFR in all lesions at the per-vessel level were 91% (with a 95% CI of 84%-96%), 92% (95% CI, 88%-95%), 83% (95% CI, 75%-90%), 96% (95% CI, 93%-98%), and 92% (95% CI, 88%-95%), with values for μQFR of 90% (95% CI, 81%-95%), 97% (95% CI, 93%-99%), 92% (95% CI, 84%-97%), 96% (95% CI, 92%-98%), and 94% (95% CI, 91%-97%), respectively. Among bifurcation, tandem, and moderate-to-severe calcified lesions, the diagnostic values of CT-QFR and μQFR showed great correlation and agreement with those of invasive fractional flow reserve, achieving an area under the receiver operating characteristic curve exceeding 0.9 for each complex lesion at the vessel level. Furthermore, the accuracies of CT-QFR and μQFR in the gray zone were 85% and 84%, respectively. Angiography-derived quantitative flow ratio (CT-QFR and μQFR) demonstrated remarkable diagnostic performance in complex coronary lesions, indicating its pivotal role in the management of patients with coronary artery disease.

Diagnostic performance of pressure-bounded coronary flow reserve.

Fluid dynamics studies have proposed that coronary flow reserve can be calculated from coronary artery pressure instead of coronary blood flow. We sought to investigate the diagnostic performance of pressure-bounded coronary flow reserve (pb-CFR) compared with CFR measured by conventional thermodilution method (CFRthermo) in the clinical setting. Pressure guidewire was used to measure CFRthermo and fractional flow reserve (FFR) in left anterior descending coronary artery in 62 patients with stable coronary artery disease. Pb-CFR was calculated only with resting distal coronary artery pressure (Pd), resting aortic pressure (Pa) and FFR. Pb-CFR was moderately correlated with CFRthermo (r = 0.54, P < 0.001). Pb-CFR showed a poor agreement with CFRthermo, presenting large values of mean difference and root mean square deviation (1.5 ± 1.4). Pb-CFR < 2.0 predicted CFRthermo < 2.0 with an accuracy of 79%, sensitivity of 83%, specificity of 78%, positive predictive value of 48%, negative predictive value of 95%. The discordance presenting CFRthermo < 2.0 and pb-CFR ≥ 2.0 was associated with diffuse disease (P < 0.001). The discordance presenting CFRthermo ≥ 2 and pb-CFR < 2 was associated with a high FFR (P = 0.002). Pb-CFR showed moderate correlation and poor agreement with CFRthermo. Pb-CFR might be reliable in excluding epicardial coronary artery disease and microcirculatory disorders.

Effect of guidewire on the accuracy of trans-stenotic pressure measurement—A computational study

Accurate measurement of trans-stenotic pressure drop is vital for risk stratification in coronary artery disease. Currently, in vivo pressure measurement relies mostly on a pressure guidewire inserted into the artery, which inevitably alters local hemodynamics. To precisely assess the impact of guidewire insertion on the accuracy of pressure measurement, this study conducts numerical simulations with both an idealized straight-tube model and a patient-specific model. Results with and without a guidewire model are compared and analyzed. Results from the idealized model reveal that the insertion of a guidewire shifts velocity distribution, increases resistance, and amplifies the pressure drop across the stenosis. The patient-specific model also demonstrates that the guidewire causes non-negligible flow redistribution among the arterial branches, but the influence on pressure drop remains mostly localized. An analytical model for trans-stenotic pressure drop that takes the guidewire into consideration is also proposed and validated against the 3D simulation results. It is observed that the maximum relative error is around 3.0% in the patient-specific model, indicating the effectiveness of the analytical model in physiologically accurate settings. The proposed model can be used to align computed tomography-derived fractional flow reserve values with clinically recognized FFR standards established through guidewire measurements.

Direct wire pacing during measurement of fractional flow reserve: A randomized proof-of-concept noninferiority crossover trial.

Adenosine administration for fractional flow reserve (FFR) measurement may induce heart pauses. To assess the accuracy and tolerability of direct wire pacing (DWP) during measurement of FFR. Adults with at least one intermediate coronary artery stenosis (40%-80%) were consecutively enrolled between June 2021 and February 2022 in this randomized, noninferiority, crossover trial (NCT04970082) carried out in France. DWP was applied (DWP) or not (standard method) through the pressure guidewire used for FFR measurement during adenosine-induced maximal hyperaemia. Subjects were randomly assigned to the allocation sequence (DWP first or standard first). A 2-minute washout period was observed between the two FFR measurements performed for each stenosis. The primary endpoint was the reproducibility of FFR measurements between methods. A total of 150 focal lesions, presented by 94 subjects, were randomized (ratio: 1:1). The FFR values obtained with each method were nearly identical (R = 0.98, p = 0.005). The mean FFR difference of 0.00054 (95% confidence interval: 0.004 to 0.003) showed the noninferiority of FFR measurement with DWP vs. that with the standard method. Higher levels of chest discomfort were reported with DWP than with the standard method (0.61 ± 0.84 vs. 1.05 ± 0.89, p < 0.001), and a correlation was observed between the electrical sensations reported with DWP and chest discomfort (p < 0.001). Pauses (n = 20/148 lesions) were observed with the standard method, but did not correlate with chest discomfort (p = 0.21). No pauses were observed with DWP. DWP during FFR measurement resulted in accurate and reproducible FFR values, and eliminated the pauses induced by adenosine.

In vivo ureteroscopic intrarenal pressures and clinicaloutcomes: a multi-institutional analysis of 120consecutive patients.

To evaluate the pressure range generated in the human renal collecting system during ureteroscopy (URS), in a large patient sample, and to investigate a relationship between intrarenal pressure (IRP) and outcome. A prospective multi-institutional study was conducted, with ethics board approval; February 2022-March 2023. Recruitment was of 120 consecutive consenting adult patients undergoing semi-rigid URS and/or flexible ureterorenoscopy (FURS) for urolithiasis or diagnostic purposes. Retrograde, fluoroscopy-guided insertion of a 0.036-cm (0.014″) pressure guidewire (COMET™ II, Boston Scientific, Marlborough, MA, USA) to the renal pelvis was performed. Baseline and continuous ureteroscopic IRP was recorded, alongside relevant operative variables. A 30-day follow-up was completed. Descriptive statistics were applied to IRP traces, with mean (sd) and maximum values and variance reported. Relationships between IRP and technical variables, and IRP and clinical outcome were interrogated using the chi-square test and independent samples t-test. A total of 430 pressure traces were analysed from 120 patient episodes. The mean (sd) baseline IRP was 16.45 (5.99) mmHg and the intraoperative IRP varied by technique. The mean (sd) IRP during semi-rigid URS with gravity irrigation was 34.93 (11.66) mmHg. FURS resulted in variable IRP values: from a mean (sd) of 26.78 (5.84) mmHg (gravity irrigation; 12/14-F ureteric access sheath [UAS]) to 87.27 (66.85) mmHg (200 mmHg pressurised-bag irrigation; 11/13-F UAS). The highest single pressure peak was 334.2 mmHg, during retrograde pyelography. Six patients (5%) developed postoperative urosepsis; these patients had significantly higher IRPs during FURS (mean [sd] 81.7 [49.52] mmHg) than controls (38.53 [22.6] mmHg; P < 0.001). A dynamic IRP profile is observed during human in vivo URS, with IRP frequently exceeding expected thresholds. A relationship appears to exist between elevated IRP and postoperative urosepsis.

OPTImized coronary interventions eXplaIn the bEst cliNical outcomEs (OPTI-XIENCE) study. Rationale and study design

IntroductionClinical events may occur after percutaneous coronary intervention (PCI), particularly in complex lesions and complex patients. The optimization of PCI result, using pressure guidewire and intracoronary imaging techniques, may reduce the risk of these events. The hypothesis of the present study is that the clinical outcome of patients with indication of PCI and coronary stent implantation that are at high risk of events can be improved with an unrestricted use of intracoronary tools that allow PCI optimization. Methods and analysisObservational prospective multicenter international study, with a follow-up of 12 months, including 1064 patients treated with a cobalt‑chromium everolimus-eluting stent. Inclusion criteria include any of the following: Lesion length > 28 mm; Reference vessel diameter < 2.5 mm or > 4.25 mm; Chronic total occlusion; Bifurcation with side branch ≥2.0 mm;Ostial lesion; Left main lesion; In-stent restenosis; >2 lesions stented in the same vessel; Treatment of >2 vessels; Acute myocardial infarction; Renal insufficiency; Left ventricular ejection fraction <30 %; Staged procedure. The control group will be comprised by a similar number of matched patients included in the “extended risk” cohort of the XIENCE V USA study. The primary endpoint will be the 1-year rate of target lesion failure (TLF) (composite of ischemia-driven TLR, myocardial infarction (MI) related to the target vessel, or cardiac death related to the target vessel). Secondary endpoints will include overall mortality, cardiovascular mortality, acute myocardial infarction, TVR, TLR, target vessel failure, and definitive or probable stent thrombosis at 1 year. ImplicationsThe ongoing OPTI-XIENCE study will contribute to the growing evidence supporting the use of intra-coronary imaging techniques for stent optimization in patients with complex coronary lesions.

Potential effects of the hydrostatic pressure gradient on hyperemic and nonhyperemic pressure ratios.

When measuring hyperemic and nonhyperemic pressure ratios with traditional sensor-tipped wires, the inevitable hydrostatic pressure gradient (HPG) may influence treatment decisions. This study aimed to simulate and analyze the effect of a hydrostatic pressure gradient on different indices of functional lesion severity. A hypothetical Pd-Pa height difference and subsequent hydrostatic pressure gradient based on previous literature was applied to the pressure measurements from the CONTRAST study. The effect on three indices of functional lesion severity (FFR, Pd/Pa, and dPR) was assessed and possible reclassifications in functional significance by the different indices were analyzed. In 602 pressure tracings, simulated hydrostatic pressure gradients led to an absolute change in Pd of 3.18 ± 1.30 mmHg, resulting in an overall increase in FFR, Pd/Pa, and dPR of 0.02 ± 0.04 for all indices (P = 0.69). Reclassification due to the hydrostatic pressure gradient when using dichotomous cutoff values occurred in 13.4, 22.3, and 20.6% for FFR, Pd/Pa, and dPR, respectively. The effect of hydrostatic pressure gradient correction differed among the coronary arteries and was most pronounced in the left anterior descending. When considering the gray zone for the different functional indices, the hydrostatic pressure gradient resulted in reclassification in only one patient out of the complete patient population (1/602; 0.17%). The hydrostatic pressure gradient can influence functional lesion assessment when using dichotomous cutoff values. When taking the gray zone into account, its effect is limited.NEW & NOTEWORTHY This study systematically simulated the effect of hydrostatic pressure gradients (HPG) on real-world hyperemic and nonhyperemic pressure ratios, showing correction for HPG leads to reclassification in functional significance from 13.4 to 22.3% for different functional indices. This was most pronounced in nonhyperemic pressure ratios. A new pressure guidewire (Wirecath) is unaffected by HPG. The ongoing PW-COMPARE study (NCT04802681) prospectively analyzes the magnitude and importance of HPG by simultaneous FFR measurements.

Microcatheter-versus wire-based measurement of the fractional flow reserve

Background Fractional flow reserve (FFR) guided-percutaneous interventions is nowadays the gold standard for optimal coronary artery revascularization. While multiple pressure guidewires have been validated, the use of microcatheter for FFR measurements is still a matter of debate. Objective The aim of this study was to investigate the crossing profile characteristics of the NAVVUS® microcatheter as compared with the COMETTM pressure wire. At the same time, we compared non-hyperaemic pressure ratio (NHPR) and FFR measurements of both systems. Method/materials In this retrospective study, all angiographically intermediate coronary artery stenoses each month were assessed, using either the NAVVUS® or the COMETTM pressure system, to receive coronary artery physiology assessment with NHPR and FFR measurements. The crossing profile of both systems was compared regarding objective coronary artery lesion characteristics using quantitative coronary analysis evaluation. Results Over a period of 4.5 years, we evaluated 213 coronary artery stenoses using one of the two coronary tools. We found a 9.2% crossing profile failure rate using the microcatheter, compared to 0.7% in the pressure wire group (p < .001). The crossing failure was significantly correlated with the presence of coronary artery calcifications and angulation (p = .042, p = .049, respectively). FFR values were comparable be- tween the two groups and were significantly lower in the presence of coronary calcifications and proportional to the degree of stenosis (p = .036, p = .010). Pressure drift was comparable. Conclusion Our observations are in line with other studies reporting the poor crossing profile of the NAVVUS® microcatheter. NHPR and FFR measures of both systems were well correlated.

Applied coronary physiology for planning and guidance of percutaneous coronary interventions. A clinical consensus statement from the European Association of Percutaneous Cardiovascular Interventions (EAPCI) of the European Society of Cardiology.

The clinical value of fractional flow reserve and non-hyperaemic pressure ratios are well established in determining an indication for percutaneous coronary intervention (PCI) in patients with coronary artery disease (CAD). In addition, over the last 5 years we have witnessed a shift towards the use of physiology to enhance procedural planning, assess post-PCI functional results, and guide PCI optimisation. In this regard, clinical studies have reported compelling data supporting the use of longitudinal vessel analysis, obtained with pressure guidewire pullbacks, to better understand how obstructive CAD contributes to myocardial ischaemia, to establish the likelihood of functionally successful PCI, to identify the presence and location of residual flow-limiting stenoses and to predict long-term outcomes. The introduction of new functional coronary angiography tools, which merge angiographic information with fluid dynamic equations to deliver information equivalent to intracoronary pressure measurements, are now available and potentially also applicable to these endeavours. Furthermore, the ability of longitudinal vessel analysis to predict the functional results of stenting has played an integral role in the evolving field of simulated PCI. Nevertheless, it is important to have an awareness of the value and challenges of physiology-guided PCI in specific clinical and anatomical contexts. The main aim of this European Association of Percutaneous Cardiovascular Interventions clinical consensus statement is to offer up-to-date evidence and expert opinion on the use of applied coronary physiology for procedural PCI planning, disease pattern recognition and post-PCI optimisation.

Intrarenal pressures during flexible ureteroscopy: aninsight into safer endourology.

To assess intrarenal pressures (IRPs) and complication rates after flexible ureteroscopy (fURS), and to assess factors that contribute to raised IRPs and postoperative complications. After informed consent patients underwent fURS under general anaesthesia. The transducer of a 0.3556 mm (0.014″) pressure guidewire was placed in the renal pelvis for live recording of IRPs. The fURS procedures were performed in a routine manner under antibiotic cover with the aim of dusting the calculus to completion. The operating surgeon was blinded to the live-recorded IRPs. A total of 40 fURS procedures were performed in 37 patients (26 male and 11 female). The mean age was 50.5 years. As a cohort, the mean of average IRPs was 34.8 mmHg and the mean of maximal IRPs was 128.8 mmHg. Pearson's correlation showed a significant inverse correlation between the mean IRP and age (r[38]: -0.391, P = 0.013). Three cases experienced postoperative deviations from uncomplicated recovery, with two being hypotensive and one case being both hypotensive and hypoxic. Three cases returned to the emergency department within 30 days of surgery, with two cases of flank pain and one case of urosepsis with positive urine cultures. The patient presenting with urosepsis had exhibited IRPs exceeding the mean. The IRPs changed significantly from normal baseline levels during routine fURS. The mean IRP during fURS correlates with patient age, but not with other factors. The IRP may be related to increased complication rates at fURS. Understanding factors that influence IRP will allow urologists to better manage this intraoperatively.

Accuracy of the angiography-based quantitative flow ratio in intermediate left main coronary artery lesions and comparison with visual estimation

BackgroundRevascularization of left main coronary artery (LMCA) stenosis is mostly based on angiography. Indices based on angiography might increase accuracy of the decision, although they have been scarcely used in LMCA. The objective of this study is to study the diagnostic agreement of QFR (quantitative flow ratio) with wire-based fractional flow reserve (FFR) in LMCA lesions and to compare with visual severity assessment. MethodsIn a series of patients with invasive FFR assessment of intermediate LMCA stenoses we retrospectively compared the measured value of QFR with that of FFR and the estimate of significance from angiography. Results107 QFR studies were included. The QFR intra-observer and inter-observer agreement was 87% and 82% respectively. The mean QFR-FFR difference was 0.047 ± 0.05 with a concordance of 90.7%, sensitivity 88.1%, specificity 92.3%, positive predictive value 88.1% and negative predictive value 92.3%. All these values were superior to those observed with the visual estimation which showed an intra- and inter-observer agreement of 73% and 72% respectively, besides 78% with the FFR value. The low diagnostic performance of the visual estimation and the acceptable performance of the QFR index measurement were observed in all subgroups analysed. ConclusionsQFR allows an acceptable estimate of the FFR obtained with intracoronary pressure guidewire in intermediate LMCA lesions, and clearly superior to the assessment based on angiography alone. The decision to revascularize patients with moderate LMCA lesions should not be based solely on the degree of angiographic stenosis.

MP05-19 WHAT IRRIGATION PRESSURES ARE SAFE? QUANTITATIVE ANALYSIS OF PYELOVENOUS BACKFLOW AT VARIOUS PRESSURES IN A PORCINE MODEL

You have accessJournal of UrologyCME1 Apr 2023MP05-19 WHAT IRRIGATION PRESSURES ARE SAFE? QUANTITATIVE ANALYSIS OF PYELOVENOUS BACKFLOW AT VARIOUS PRESSURES IN A PORCINE MODEL Anne Hong, Greg Jack, and Damien Bolton Anne HongAnne Hong More articles by this author , Greg JackGreg Jack More articles by this author , and Damien BoltonDamien Bolton More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003216.19AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Irrigation fluid is required for visualization during ureteroscopy and pyeloscopy. Pressurized irrigation can result in pyelovenous backflow of irrigation into the vascular system providing a mechanism for urosepsis. We aim to quantify the amount of irrigation substrate that is absorbed via pyelovenous backflow at various pressures. METHODS: 6 deceased donor porcine kidneys were flushed with 1 L heparinized saline and preserved on ice using a renal transplant protocol. The renal artery was cannulated with a 10Fr catheter and perfused continuously with 0.9% normal saline solution (pH 6.77) at mean arterial pressure of 90 mmHg to simulate arterial blood flow. A steady state of venous effluent from the renal vein was achieved and collected continuously from the renal vein for the duration of the study. The ureter was cannulated with a 10Fr dual lumen ureteric catheter and the tip placed at the ureteropelvic junction and fixed in place with silk ties around the ureter. A pressure monitor (Comet II Pressure Guidewire®, Boston Scientific Corporation, Massachusetts, United States) was inserted through one lumen and positioned in the renal pelvis for continuous renal pelvis irrigation pressure monitoring. Distilled white vinegar (8% acetic acid, pH 3.32) was infused under pressure through the ureteral access catheter at various renal pelvic pressures (RPPs) to replicate pyeloscopy irrigation. RPP was increased in 15mmHg increments every 3 minutes and the venous effluent was collected at each increment. A control arm was conducted using RPP fixed at 30 mmHg for the duration of the 1 hour study with the venous effluent collected in the same 3 minute intervals. Statistical comparisons were performed using Wilcoxon rank test to compare the 15 mmHg increments. RESULTS: Figure 1 show venous pH following simulated ureteroscopy with 8% acetic acid at increasing RPP. Wilcoxon rank test demonstrated that from 90 mmHg onwards, the changes in pH were statistically significant. CONCLUSIONS: Ureteral irrigation fluids are initially detected in the renal venous effluent in trace amounts when renal pelvis irrigation pressures exceed 60 mmHg, and are statistically significant when RPP exceeds 90 mmHg. Source of Funding: Nil © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e51 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Anne Hong More articles by this author Greg Jack More articles by this author Damien Bolton More articles by this author Expand All Advertisement PDF downloadLoading ...

MP35-04 SERIAL MANUAL “PUMP” IRRIGATION LEADS TO CRITICAL INTRA-RENAL PRESSURES DURING URETERO-RENOSCOPY – TIME TO ABANDON THIS MANOEUVRE

You have accessJournal of UrologyCME1 Apr 2023MP35-04 SERIAL MANUAL “PUMP” IRRIGATION LEADS TO CRITICAL INTRA-RENAL PRESSURES DURING URETERO-RENOSCOPY – TIME TO ABANDON THIS MANOEUVRE Anne Hong, Gregory Jack, Cliodhna Browne, and Damien Bolton Anne HongAnne Hong More articles by this author , Gregory JackGregory Jack More articles by this author , Cliodhna BrowneCliodhna Browne More articles by this author , and Damien BoltonDamien Bolton More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003269.04AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Ureteroscopy has become the dominant method of managing urolithiasis. Various methods of irrigation can be utilized to maintain clear views. One such method is the manual pump irrigation, whereby a bolus of fluid is delivered from a chamber in the irrigation system. However raised intrarenal pressures (IRPs) during ureteroscopy consequently ensue, and are of concern due to associated post operative complications. Clinically, this has been correlated with outcomes such as infection, pain, and excessive fluid absorption. We aimed to characterise the increases and maximal IRPs produced by manual pump irrigation used during uretero-renoscopy. METHODS: During the uretero-renoscopy procedure a Comet II Pressure Guidewire® (Boston Scientific Corporation, Marlborough, Massachusetts, USA) was used for IRP measurement. Routine flexible uretero-renoscopy for treatment of urolithiasis was undertaken, including manual pump irrigation where this was required to maintain vision. The baseline IRPs, maximal IRPs and the difference between the two were calculated. RESULTS: A total of 17 single manual pump manoeuvres were observed during treatment of this cohort. The median baseline IRP was 36.5 mmHg, the median rise in IRP was 29.4 mmHg, and the median maximum IRP achieved was 76.0 mmHg. A total of 24 serial manual pump manoeuvres were analyzed with the median baseline 39.3 mmHg. After the serial hand pump maneuver, the median rise in IRP was 72.3 mmHg, with the median maximum IRP achieved being 114.1 mmHg. CONCLUSIONS: Manual pump irrigation - both single but particularly serial maneuvers - produces significant rises in IRPs and that could logically result in pyelo-venous backflow and sepsis. Our results suggest that this manoeuvre should be avoided, in order to reduce potential complications of flexible uretero-renoscopy. Source of Funding: None © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e469 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Anne Hong More articles by this author Gregory Jack More articles by this author Cliodhna Browne More articles by this author Damien Bolton More articles by this author Expand All Advertisement PDF downloadLoading ...