Poor Distal Perfusion Research Articles

Measuring Peri-Anastomotic Pressure to Identify Patients at High-Risk for Dialysis Associated Steal Syndrome

Dialysis Access-associated Steal Syndrome (DASS) is one of the most serious complications of hemoaccess surgery. Treatment algorithms involve significant morbidity; a tool to reliably identify patients at risk who could benefit from interventions at time of operation would be useful. We present a strategy of using peri-anastomotic pressure (PAP) measurement to identify patients who may be at high risk of developing DASS. Patients who underwent dialysis access creation between January 1, 2018 and September 30, 2022 at our institution were reviewed. Beginning October 2019, we developed a strategy of measuring systolic pressure at the arterial anastomosis intra-operatively. A ratio of this value compared to the systemic systolic pressure was calculated. In patients believed to be high-risk for developing DASS based on clinical findings, selective banding of the access was performed intra-operatively to augment distal perfusion. Of 857 total patients, 36 (4.2%) developed clinically significant DASS, defined as requiring operative treatment, either intraoperatively or during follow-up (mean, 76 days; range, 0-602 days). DASS was more common for femoral-based accesses (6/12, 46.2%) compared to upper extremity accesses (30/840, 3.6%, p < 0.001). No patients who underwent radiocephalic arteriovenous fistula (AVF) or infraclavicular axillary arteriovenous graft construction developed DASS. There was no difference in DASS for upper extremity AVFs (20/576, 3.47%) vs. AV grafts (10/264, 3.79%, p = 0.82). 216 patients had PAP measured intra-operatively. Fourteen (6.5%) of these 216 patients developed DASS requiring intervention in follow-up. The mean PAP ratio of these 14 patients was 0.395 vs. 0.557 for the 202 patients who did not [CI 0.07-0.25, p = 0.001]. Seventeen patients who had low PAP ratio with poor distal perfusion underwent intra-operative banding, which improved mean PAP ratios from a mean of 0.33 to 0.58. Despite banding, 3 of these 17 (17.6%) patients in this high-risk subgroup went on to develop DASS postoperatively. The calculated mean PAP ratio in patients who either developed DASS post-operatively or underwent prophylactic banding intra-operatively was 0.37, which was significantly lower than the mean ratio of 0.57 in the control group (p = 0.001). Low PAP ratios (less than 0.50) identified patients at elevated risk for DASS, but prophylactic banding did not always prevent the occurrence of DASS in select patients. Because steal is a dynamic phenomenon, intraoperative conditions are not always going to reflect later adaptation. Nonetheless, PAP measurement may identify a subgroup warranting procedural modification or closer postoperative physiologic monitoring.

MP65-19 OPEN FIELD NEAR-INFRARED FLUORESCENCE ANGIOGRAPHY IS A USEFUL TOOL TO ASSESS TISSUE INTEGRITY IN COMPLEX, OPEN, GENITOURINARY RECONSTRUCTIVE SURGERY

You have accessJournal of UrologyCME1 Apr 2023MP65-19 OPEN FIELD NEAR-INFRARED FLUORESCENCE ANGIOGRAPHY IS A USEFUL TOOL TO ASSESS TISSUE INTEGRITY IN COMPLEX, OPEN, GENITOURINARY RECONSTRUCTIVE SURGERY Elizabeth Bearrick, Bridget Findlay, Paige Nichols, Kevin Hebert, Katherine Anderson, and Boyd Viers Elizabeth BearrickElizabeth Bearrick More articles by this author , Bridget FindlayBridget Findlay More articles by this author , Paige NicholsPaige Nichols More articles by this author , Kevin HebertKevin Hebert More articles by this author , Katherine AndersonKatherine Anderson More articles by this author , and Boyd ViersBoyd Viers More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003323.19AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Genitourinary reconstructive surgery frequently involves high-risk patient populations with compromised tissue perfusion – a risk factor for poor reconstructive outcomes. Traditionally, intraoperative tissue viability characterization relies on direct and subjective surgeon assessment. Intravascular indocyanine green (ICG) combined with open field near-infrared fluorescence (NIRF) imaging enables objective quantification of tissue perfusion and viability. Herein, we sought to compare open subjective intraoperative surgeon and objective ICG angiography assessment in radiated patients undergoing complex urologic reconstruction. METHODS: A retrospective single surgeon review of 39 patients (40 surgeries) in which SPY-PHI (Stryker Kalamazoo, MI) was utilized during open, complex genitourinary reconstructive surgery between June 2018 and April 2022. Differences in altered surgical decision making, ureteral perfusion characteristics, complications, and reconstructive success were assessed. RESULTS: There were 39 patients with a median age of 66 who underwent 40 multimodality reconstructive surgeries during which open ICG angiograpy was utilized with median follow-up 23.4 months. Surgery was performed for radiation induced complications in 32 of 40 (80%). Among patients with documentation of ureteral length evaluation (N=16), median subjective vs objective assessment of poor distal perfusion was 1.8 cm vs 3.2 cm (p=0.001). In total, discordance in perfusion assessment was noted in 19(61%) of ureters. In 25 (63%) cases, use of ICG angiography influenced intraoperative surgical decision making. ICG angiography was significantly more likely to impact surgical decision making in radiated vs non-irradiated cases (23(72%) vs 1 (13%); p=0.007). There was 1 complication in the non-irradiated cohort and 12 complications in the radiated cohort. At a median follow-up of 23 months, 1 (3%) patient in the radiation cohort developed a ureteroenteric anastomotic stricture. CONCLUSIONS: Among patients with radiation injury undergoing complex open urinary reconstruction, utilization of ICG angiography revealed a high-level of operative discordance compared to subjective surgeon assessment and ultimately influenced surgical decision making. Reassuring reconstructive outcomes noted in this population would suggest that ICG angiography is a useful tool in complex open genitourinary reconstructive surgery. Source of Funding: None © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e899 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Elizabeth Bearrick More articles by this author Bridget Findlay More articles by this author Paige Nichols More articles by this author Kevin Hebert More articles by this author Katherine Anderson More articles by this author Boyd Viers More articles by this author Expand All Advertisement PDF downloadLoading ...

V01-02 USE OF SPY FLUORESCENT ANGIOGRAPHY DURING URINARY DIVERSION

You have accessJournal of UrologyCME1 May 2022V01-02 USE OF SPY FLUORESCENT ANGIOGRAPHY DURING URINARY DIVERSION Grace Prillaman, Clinton Yeaman, Sumit Isharwal, and Tracey Krupski Grace PrillamanGrace Prillaman More articles by this author , Clinton YeamanClinton Yeaman More articles by this author , Sumit IsharwalSumit Isharwal More articles by this author , and Tracey KrupskiTracey Krupski More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002520.02AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Ureteroenteric strictures (UES) are a common complication of radical cystectomy and urinary diversions. UES occurs in 4-25% of all patients undergoing urinary diversion. Anastomotic ischemia is implicated in the formation of stricture. We aim to describe the method for using SPY fluorescent angiography during open urinary diversion. METHODS: Evaluation of ureteral perfusion is commonly performed during robotic-assisted intracorporeal urinary diversion using indocyanine green (ICG) and firefly technology which allow for the detection of ICG indicating perfusion but provides no information on the density of perfusion. SPY is a similar technology that can be employed during open surgery that allows for the visualization of green ICG tracer but also provide a heat map that indicates density of vascularization. ICG dye is administered via IV before the bowel work to create the conduit segment is begun. Ureteral perfusion is assessed using SPY technology to visualize the tracer and perfusion density. SPY has 3 modes of fluorescence: standard green fluorescence, black and white mode, and heatmap mode. The black and white is most sensitive for determining perfusion to tissue. The distal-most aspect of the well perfused ureter is marked with a stitch. If the ureter has poor distal perfusion, it can be resected proximally. A conduit is created, and the bowel is anastomosed accordingly. After both ureteral anastomoses are complete, ICG is again administered via IV to assess for perfusion in the post-anastomosis ureter. RESULTS: We are conducting an ongoing prospective trial to better define the role and benefit of SPY. We have enrolled 16 patients to date with median follow-up time of 4.7 months and have not detected any ureteroenteric strictures within the experimental group. Our institutional rate of UES in patients who did not have SPY fluorescent angiography is 10.3%. CONCLUSIONS: SPY fluorescent angiography can be used during open urinary diversion to ensure perfusion to ureteroenteric anastomosis. Research is ongoing to assess its role in urinary diversion and the prevention of ureteroenteric strictures. Source of Funding: N/A © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e52 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Grace Prillaman More articles by this author Clinton Yeaman More articles by this author Sumit Isharwal More articles by this author Tracey Krupski More articles by this author Expand All Advertisement PDF DownloadLoading ...

Cardiac Tamponade in Eisenmenger Syndrome: A Diagnosing Complexity: Case Report

Cardiac tamponade is a form of obstructive shock with clinical manifestations consistent with a low cardiac output and high central venous pressure. Features of a low cardiac output include low mean arterial pressure, cold peripheries and signs of poor end-organ perfusion. Characteristically, palpating the pulse reveals an apparent variation in pulse volume because of pulsus paradoxus. Jugular venous pressure is typically increased, with distended neck veins apparent. Sympathetic tone is increased in an attempt to compensate for the low cardiac output and manifests as tachycardia, diaphoresis, anxiety [1] and poor distal perfusion determining the need for emergent Pericardiocentesis. We report a case where an hemodynamically significant pericardial effusion with indication of pericardiocentesis had presented without classic signs of tamponade. It is an unusual and rare case of large pericardial effusion in the setting of Eisenmenger syndrome where only clinical signs as worsening hypoxia and cyanosis due to the right to left shunt was the warning sign of cardiac tamponade requiring pericardiocentesis.

Infarct Recurrence in Intracranial Atherosclerosis: Results from the MyRIAD Study

BackgroundIntracranial atherosclerotic disease (ICAD) is a common cause of ischemic stroke with a high risk of clinical stroke recurrence. Multiple mechanisms may underlie cerebral ischemia in this condition. The study's objective is to discern the mechanisms of recurrent ischemia in ICAD through imaging biomarkers of impaired antegrade flow, poor distal perfusion, abnormal vasoreactivity, and artery-to-artery embolism. MethodsThis prospective multicenter observational study enrolled patients with recent (≤21 days) ischemic stroke or transient ischemic attack (TIA) caused by ICAD with 50-99% stenosis treated medically. We obtained baseline quantitative MRA (QMRA), perfusion MRI (PWI), transcranial Doppler vasoreactivity (VMR), and emboli detection studies (EDS). The primary outcome was ischemic stroke in the territory of the stenotic artery within 1 year of follow-up; secondary outcomes were TIA at 1 year and new infarcts in the territory on MRI at 6-8 weeks. ResultsAmongst 102 of 105 participants with clinical follow-up (mean 253±131 days), the primary outcome occurred in 8.8% (12.7/100 patient-years), while 5.9% (8.5/100 patient-years) had a TIA. A new infarct in the territory of the symptomatic artery was noted in 24.7% at 6-8 weeks. A low flow state on QMRA was noted in 25.5%, poor distal perfusion on PWI in 43.5%, impaired vasoreactivity on VMR in 67.5%, and microemboli on EDS in 39.0%. No significant association was identified between these imaging biomarkers and primary or secondary outcomes. ConclusionsDespite intensive medical management in ICAD, there is a high risk of clinical cerebrovascular events at 1 year and an even higher risk of new imaging-evident infarcts in the subacute period after index stroke. Hemodynamic and plaque instability biomarkers did not identify a higher risk group. Further work is needed to identify mechanisms of ischemic stroke and infarct recurrence and their consequence on long-term physical and cognitive outcomes. Trial RegistrationClinicalTrials.gov: NCT02121028.

The evaluation of prevalence of poor distal leg perfusion in totally endoscopic cardiac surgeries: a cohort study

Introduction To ensure patient safety during Totally Endoscopic Cardiac Surgeries (TECS), patients are peripherally cannulated for coupling to the Cardiopulmonary Bypass (CPB) (1). Despite its necessity, the cannulated leg might experience clinically relevant ischemia (CRI), defined as a minimum of 15% Tissue Oxygenation Index (TOI) drop, lasting at least 4 minutes, possibly leading to poor peri- and postoperative clinical outcomes (2). TOI-values were assessed using non-invasive, Near-Infrared Spectroscopy (NIRS; 200NX-NIRO, Hamamatsu®, Japan) measurements of the skin covering the ipsilateral calf muscles. NIRS enables the quantification of the TOI, based on the difference in light absorption between oxygenated en deoxygenated haemoglobin molecules. The 200NX-NIRO has shown great sensitivity and specificity in the clinical setting (3-5). The objective was to evaluate the prevalence of poor distal leg perfusion related to short-term, peri-operative, CPB-time, since these data remain largerly unknown. Methods All consecutive patients 18 years or older, and scheduled for a TECS-based valve surgery (YIL AVR and/or MVATS), coronary surgery (ENDO ACAB or ENDO CABG), or a combination were included. Perioperative TOI-values were assessed at: baseline (B) = 5 minutes before insertion of the femoral arterial cannula (FAC); Event 1 (E1) = insertion of the FAC; Event 2 (E2) = onset of CPB; Event 3 (E3) = offset of CPB; Event 4 (E4) = removal of the FAC. Results 116 patients were included for statistical analysis. Differences between TOI-values were analysed using Wilcoxon signed rank tests. CRI in the cannulated leg was demonstrated in 18,80% (n = 22) of all cases, and showed significantly lower TOI-values for all events (E1, E2, E3 and E4) compared to the baseline TOI-value (Figure 1): p Discussion Although not all patients showed CRI in the cannulated leg, some degree of hypoperfusion was demonstrated over all cannulated legs. However, these are interim results and thus, further research regarding postoperative follow-up is necessary and might offer insights on how to prevent or prematurely treat ischemia and/or ischemia-related complications in the subclinical stage.

Mechanisms of early Recurrence in Intracranial Atherosclerotic Disease (MyRIAD): Rationale and design

RationaleIntracranial atherosclerotic disease (ICAD) is the most common cause of ischemic stroke with the highest rate of recurrence, despite aggressive medical management. Diverse mechanisms may be responsible for ICAD-related cerebral ischemia, with potential therapeutic implications. Here we present the rationale, design and methods of the Mechanisms of Early Recurrence in Intracranial Atherosclerotic Disease (MyRIAD) study. The aim of MyRIAD is to determine the mechanisms of stroke in ICAD through physiologic imaging biomarkers that evaluate impaired antegrade flow, poor distal perfusion, abnormal vasoreactivity, artery to artery embolism, and their interaction. Methods and designThis is a prospective observational study of patients with recently symptomatic (<21 days) ICAD with 50–99% stenosis treated medically and monitored for up to 1 year. An estimated 110 participants are recruited at 10 sites to identify the association between the presence of each mechanism of ischemia and recurrent stroke. The primary outcome is ischemic stroke in the territory of the symptomatic artery. Secondary outcomes include new cerebral infarction on MRI at 6–8 weeks and recurrent TIA in the territory of the symptomatic artery. DiscussionMyRIAD is positioned to define the role of specific mechanisms of recurrent ischemia in patients with symptomatic ICAD. This knowledge will allow the development and implementation of effective and specific treatments for this condition.

Prevalence and Predictors of Poor Distal Leg Perfusion in Minimally Invasive Cardiac Surgery.

Prevalence and Predictors of Poor Distal Leg Perfusion in Minimally Invasive Cardiac Surgery.

Real-time indocyanine green angiography with the SPY fluorescence imaging platform decreases benign ureteroenteric strictures in urinary diversions performed during radical cystectomy.

Background:Ischemia is thought to contribute to benign ureteroenteric stricture (UES) after radical cystectomy with urinary diversion (RCUD). Our institution adopted the use of ureteral perfusion assessment during all RCUDs using real-time indocyanine green angiography using the SPY fluorescence imaging platform (Stryker Corp., Kalamazoo, MI, USA). This guides the location of ureteral transection prior to ureteroenteric anastomosis. We sought to compare UES rates before and after adoption of SPY.Methods:A retrospective chart review was undertaken for the first 47 consecutive cases of RCUD using SPY as well as the previous 47 consecutive cases, which were performed without SPY. Fisher’s exact and Wilcoxon rank-sum tests were used to compare benign UES rates and the length of ureter excised during anastomosis. A p < 0.05 indicated statistical significance.Results:Median follow up was 12.0 months for SPY cases and 24.3 months for non-SPY cases. The UES rate for SPY RCUDs was 0% (0/93 ureters) compared with 7.5% (7/93 ureters) for non-SPY RCUDs (p = 0.01). Amongst SPY RCUDs, 86 ureters had no hydronephrosis and 7 had mild hydronephrosis with reflux on loopogram. A total of 34.4% of ureters (32/93) had poor distal perfusion, requiring a more proximal anastomosis. The median length excised for ureters with poor distal perfusion was 3.8 cm, compared with 2.2 cm for ureters with good distal perfusion (p < 0.0001). No complications attributable to the use of SPY were noted.Conclusion:Use of SPY to assess ureteral perfusion was associated with a decrease in the UES rate after RCUD. A total of 34.4% of ureters demonstrated poor distal perfusion, requiring a significantly more proximal ureteroenteric anastomosis.

Endothelial Nuclear Factor-κB–Dependent Regulation of Arteriogenesis and Branching

Arteriogenesis and collateral formation are complex processes requiring integration of multiple inputs to coordinate vessel branching, growth, maturation, and network size. Factors regulating these processes have not been determined. We used an inhibitor of NFκB activation (IκBαSR) under control of an endothelial-specific inducible promoter to selectively suppress endothelial nuclear factor-κB activation during development, in the adult vasculature, or in vitro. Inhibition of nuclear factor-κB activation resulted in formation of an excessively branched arterial network that was composed of immature vessels and provided poor distal tissue perfusion. Molecular analysis demonstrated reduced adhesion molecule expression leading to decreased monocyte influx, reduced hypoxia-inducible factor-1α levels, and a marked decrease in δ-like ligand 4 expression with a consequent decrease in Notch signaling. The latter was the principal cause of increased vascular branching as treatment with Jagged-1 peptide reduced the size of the arterial network to baseline levels. These findings identify nuclear factor-κB as a key regulator of adult and developmental arteriogenesis and collateral formation. Nuclear factor-κB achieves this by regulating hypoxia-inducible factor-1α-dependent expression of vascular endothelial growth factor-A and platelet-derived growth factor-BB, which are necessary for the development and maturation of the arterial collateral network, and by regulating δ-like ligand 4 expression, which in turn determines the size and complexity of the network.

Effective Management of Sarin Exposure

Biological and chemical warfare training is often overlooked in residency programs, but is nonetheless an extremely important part of the curriculum and should be implemented before allowing residents to graduate. The purpose of this case is twofold: (1) explore the diagnosis and treatment of Sarin exposure, (2) discuss the methods of protecting against contamination with toxic agents.

Paraplegia and traumatic rupture of the aorta: a disease process or surgical complication?

Surgical repair of traumatic rupture of the aorta results in an excellent survival rate especially among the young, although paraplegia continues to be a serious postoperative complication. The authors present nine cases admitted to Stoke Mandeville Hospital, England, including detailed post-mortem findings on one of the cases. Although it was difficult to be certain of the patients' general and neurological status prior to surgery, as it was not well documented in the patients' case notes, it was evident that systemic hypotension and poor distal aortic perfusion were responsible for the disabling complication. A review of the initial medical management of these patients and the surgical techniques employed in repairing such injuries is urgently needed.

Limb Salvage in Diabetics: Challenges and Solutions

Our current understanding of wound healing in the diabetic suggests that proper management of the blood glucose level is a necessary but not sufficient condition for containment of infection and optimal wound healing. The pathologic changes observed in the peripheral capillary bed of diabetics are somewhat variable and have no consistent relationship to the wound healing process. Occlusive disease of the arterioles is probably quite similar in significance and distribution to normoglycemic patients with peripheral vascular disease and suggests that proximal arterial occlusion is the major determinant of poor distal perfusion. These observations offer strong evidence that sufficient runoff vessels are present to support attempts at reconstruction of obstructing lesions of the aortoiliac and infrainguinal arterial segments. Noninvasive vascular laboratory data and arteriograms must be carefully interpreted in order to assess fully the degree of arterial occlusive disease that exists as well as the potential for vascular reconstruction. Clinical experience is especially helpful in proper patient selection. Aggressive attempts at distal revascularization can achieve functional limb salvage in the great majority of patients, provided that meticulous technical standards are observed. Conservative surgical debridement and minor amputations are often successful in managing problems of soft-tissue necrosis once pulsatile flow has been restored.

Continuous-wave Doppler in the intraoperative assessment of carotid endarterectomy.

A sterile 8.5 MHz continuous-wave Doppler probe was used intraoperatively to evaluate the technical result of 229 consecutive carotid endarterectomies. Primary areas of evaluation included the proximal point of plaque transection and the internal and external carotid arteries at and distal to the termination of the endarterectomy. Subjective interpretation was made of the Doppler audio signal. Signs associated with inadequate technical results were a high-frequency signal indicative of luminal narrowing with a reduction in frequency distal to the area of stenosis, absence of a Doppler signal indicating occlusion, and a weak monophasic flow signal indicating poor distal perfusion. Abnormal signals were identified in 10 internal carotid arteries (4.3%) which prompted intraoperative angiography in eight and immediate reopening of the artery in an additional two. Significant lesions were identified in seven arteries (70%). Twenty external carotid lesions (8.7%) were detected by Doppler and in 19 cases (95%) a significant stenosis or obstruction was found when the vessel was reopened. Auscultation of a continuous-wave Doppler signal with a sterile probe at operation appears to have a high positive predictive value in the identification of both internal and external carotid stenoses. It is rapid, safe, relatively inexpensive, and avoids the problems associated with routine intraoperative angiography.

Continuous-wave doppler in the intraoperative assessment of carotid endarterectomy

A sterile 8.5 MHz continuous-wave Doppler probe was used intraoperatively to evaluate the technical result of 229 consecutive carotid endarterectomies. Primary areas of evaluation included the proximal point of plaque transection and the internal and external carotid arteries at and distal to the termination of the endarterectomy. Subjective interpretation was made of the Doppler audio signal. Signs associated with inadequate technical results were a high-frequency signal indicative of luminal narrowing with a reduction in frequency distal to the area of stenosis, absence of a Doppler signal indicating occlusion, and a weak monophasic flow signal indicating poor distal perfusion. Abnormal signals were identified in 10 internal carotid arteries (4.3%) which prompted intraoperative angiography in eight and immediate reopening of the artery in an additional two. Significant lesions were identified in seven arteries (70%). Twenty external carotid lesions (8.7%) were detected by Doppler and in 19 cases (95%) a significant stenosis or obstruction was found when the vessel was reopened. Auscultation of a continuous-wave Doppler signal with a sterile probe at operation appears to have a high positive predictive value in the identification of both internal and external carotid stenoses. It is rapid, safe, relatively inexpensive, and avoids the problems associated with routine intraoperative angiography.