Geometric Indices for Predicting Ischemic Mitral Regurgitation: Correlation of Mitral Valve Coaptation Area With Tenting Height, Tenting Area and Tenting Volume.

OBJECTIVES: Ischemic remodeling of the left ventricle in patients with coronary artery disease (CAD) results in geometric changes of the mitral valve (MV) apparatus, leading to reduced MV leaflet coaptation. Although the calculation of the coaptation area has value in assessing the effects of left ventricular remodeling on the MV, it is difficult and time-consuming to measure. In this study the authors hypothesized that the tenting volume (TV) would have a greater association with coaptation area than tenting height (TH) or tenting area (TA). DESIGN: A retrospective review. SETTING: A single tertiary-care academic hospital. PARTICIPANTS: There were 145 adult patients who underwent coronary artery bypass graft surgery between April 2018 and July 2020. MEASUREMENTS AND MAIN RESULTS: Intraoperative 2- and 3-dimensional transesophageal echocardiographic studies were obtained in the precardiopulmonary bypass period. Offline analysis was used to obtain TH, TA, TV and coaptation area for each patient. Correlation between the coaptation area and the TH, TA, and TV was conducted using Pearson's correlation. The median age of the population was 68.0 years (61.0-73.3), the body mass index was 29.0 kg/m2 (25.7-33.5), and 17.8% were females. Increases in TV were the most reliable predictor of decreases in coaptation area (R2 = 0.75) followed by TA (R2 = 0.48) and TH (R2 = 0.47). CONCLUSION: As a representative of the complete topography of the MV, the authors' study demonstrated that in patients with CAD, TV has a greater negative correlation with coaptation area as compared to TH or TA.

Preclinical Proficiency-Based Model of Ultrasound Training.

BACKGROUND: Graduate medical education is being transformed from a time-based training model to a competency-based training model. While the application of ultrasound in the perioperative arena has become an expected skill set for anesthesiologists, clinical exposure during training is intermittent and nongraduated without a structured program. We developed a formal structured perioperative ultrasound program to efficiently train first-year clinical anesthesia (CA-1) residents and evaluated its effectiveness quantitatively in the form of a proficiency index. METHODS: In this prospective study, a multimodal perioperative ultrasound training program spread over 3 months was designed by experts at an accredited anesthesiology residency program to train the CA-1 residents. The training model was based on self-learning through web-based modules and instructor-based learning by performing perioperative ultrasound techniques on simulators and live models. The effectiveness of the program was evaluated by comparing the CA-1 residents who completed the training to graduating third-year clinical anesthesia (CA-3) residents who underwent the traditional ultrasound training in the residency program using a designed index called a "proficiency index." The proficiency index was composed of scores on a cognitive knowledge test (20%) and scores on an objective structured clinical examination (OSCE) to evaluate the workflow understanding (40%) and psychomotor skills (40%). RESULTS: Sixteen CA-1 residents successfully completed the perioperative ultrasound training program and the subsequent evaluation with the proficiency index. The total duration of training was 60 hours of self-based learning and instructor-based learning. There was a significant improvement observed in the cognitive knowledge test scores for the CA-1 residents after the training program (pretest: 71% [0.141 ± 0.019]; posttest: 83% [0.165 ± 0.041]; P < .001). At the end of the program, the CA-1 residents achieved an average proficiency index that was not significantly different from the average proficiency index of graduating CA-3 residents who underwent traditional ultrasound training (CA-1: 0.803 ± 0.049; CA-3: 0.823 ± 0.063, P = .307). CONCLUSIONS: Our results suggest that the implementation of a formal, structured curriculum allows CA-1 residents to achieve a level of proficiency in perioperative ultrasound applications before clinical exposure.

Open Abdominal Aortic Aneurysm Surgery and Renal Dysfunction; Association of Demographic and Clinical Variables with Proximal Clamp Location.

BACKGROUND: While cross-clamp site is a known risk factor for postoperative acute and chronic renal dysfunction following open abdominal aortic aneurysm surgery (AAA), the additive impact of patient demographic and clinical factors is lacking. In this study, we investigated the impact of body mass index (BMI), surgical duration and aneurysm diameter on the association between proximal cross-clamp location and postoperative renal dysfunction. METHODS: In this study, we conducted a retrospective analysis of 4,197 patients undergoing open AAA surgery between 2011 and 2018 using data housed in the American College of Surgeons National Safety Quality Improvement Program (ACS-NSQIP) database. The primary outcome was renal dysfunction, which was defined as patients requiring dialysis within 30 days or patients with ≥2 mg/dL rise in creatinine from baseline. We assessed the incidence of renal dysfunction with regard to clamp location and subsequently used multivariable logistic regression to assess clinical and demographic factors associated with renal dysfunction. We used a regression model to plot the association of BMI, surgical duration, and aneurysm diameter with an adjusted probability of postoperative acute and chronic renal dysfunction for individual cross-clamp locations. RESULTS: Of the 4,197 patients analyzed, 405 patients (9.6%) developed renal dysfunction within 30 days with 287 patients requiring dialysis. Patients with supraceliac clamp location had the highest incidence of renal dysfunction (20.4%). Our data showed a significant association of renal dysfunction with higher BMI patients [OR 1.04 (1.02, 1.07), P = 0.001], longer operative times [OR1.01 (1.01, 1.02), P < 0.001], clamp location between the superior mesenteric artery (SMA) and renal artery [OR 1.80 (1.17, 2.78), P = 0.007] and supraceliac clamp location [OR 2.47 (1.62, 3.76), P < 0.001]. CONCLUSIONS: The incidence of renal dysfunction increases with suprarenal clamps. Patients with higher BMI, longer operative times, and increasing aneurysm diameter, and a suprarenal clamp have a significantly increased risk of renal dysfunction compared to those who also had a suprarenal clamp but lower BMI, shorter operative times and smaller aneurysm diameter.

A Sequential Approach for Echocardiographic Guidance of Transseptal Puncture: The PITLOC Protocol.

With advancements in technology and progress in interventional procedures, left-sided structural heart disease (SHD) interventions have become part of everyday clinical practice. One of the most important steps for a successful left-sided structural heart intervention is the transseptal puncture (TSP). Appropriate transesophageal echocardiographic (TEE) guidance of TSP requires extensive supervised hands-on experience prior to attaining proficiency. Whereas some TEE skills are acquired during cardiac anesthesia fellowships, continuous procedural guidance during SHD interventions requires substantial hands-on experience. Several studies have emphasized the value of advanced training in imaging for SHD interventions; however, the pathways and advanced training to ensure proficiency in interventional echocardiography have not yet been clearly established. In an effort to achieve a uniform and consistent approach to TSP imaging that is homogeneous and complementary to the component steps of the TSP procedure from an interventional point-of-view, the authors have developed a protocol for providing image guidance for TSP - the PITLOC protocol (Practice, Identification of septal puncture needle, Tracking of needle tip, Localization of needle tip in fossa ovalis, Optimizing septal indentation, and, finally, Crossing the interatrial septum under direct vision). This protocol aims to standarize image guidance for TSP while complementing the the steps of the procedure as performed and described by interventionalists.

Echocardiographic Assessment of the Mitral Valve for Suitability of Repair: An Intraoperative Approach From a Mitral Center.

Intraoperative echocardiography of the mitral valve in the precardiopulmonary bypass period is an integral part of the surgical decision-making process for assessment of suitability for repair. Although there are comprehensive reviews in the literature regarding echocardiographic examination of the mitral valve, the authors present a practical stepwise algorithmic workflow to make objective recommendations. Advances in echocardiography allow for quantitative geometric analyses of the mitral valve, along with precise assessment of the valvular apparatus with three-dimensional echocardiography. In the precardiopulmonary bypass period, echocardiographers are required to diagnose and quantify valvular dysfunction, assess suitability for repair, assist in annuloplasty ring sizing, and determine the success or failure of the surgical procedure. In this manuscript the authors outline an algorithmic approach to intraoperative echocardiography examination using two-dimensional and three-dimensional modalities to objectively analyze mitral valve function and assist in surgical decision-making.

Three-Dimensional Printing of Patient-Specific Heart Valves: Separating Facts From Fiction and Myth From Reality.

The development of prosthetic heart valves by Dr. Charles Hufnagel in 1952 was a major clinical innovation; however, it was not an ideal solution. Mechanical prosthetic heart valves are rigid, immunogenic, require anticoagulation, do not grow with the patient, and have a finite life.1 An ideal prosthetic valve should overcome all these limitations. Considering the prevalence of valvular heart disorders, there is considerable interest in the creation of patient-specific heart valves. Following the introduction of three-dimensional (3D) printing in 1986 by Chuck Hill, rapid advances in multimodality 3D imaging and modeling have led to a generation of tangible replicas of patient-specific anatomy. The science of organogenesis has gained importance for a multitude of valid reasons: as an alternate source of organs, for realistic drug testing, as an alternative to animal testing, and for transplants that grow with the patient. What scientists imagined to be seemingly impossible in the past now seems just a step away from becoming a reality. However, due to the disruptive nature of this technology, often there are commercially-motivated claims of originality and overstatement of the scope and applicability of 3D printing. It often is difficult to separate fact from fiction and myth from reality. In this manuscript, the authors have reviewed the historic perspective, status of the basic techniques of organogenesis with specific reference to heart valves, and their potential.

Three-Dimensional Transesophageal Echocardiography Simulator: New Learning Tool for Advanced Imaging Techniques.

The use of intraoperative three-dimensional (3D) transesophageal echocardiography (TEE) has grown exponentially in recent years. Three-dimensional TEE technology has evolved to allow for real-time display of 3D images and, thus, has become the standard of care for the evaluation of cardiac anatomy and function. Its use has provided a new dimension of clinical insight when managing patients for cardiac surgery or structural heart interventions. While the intraoperative utility of 3D TEE has expanded, there has been a slower advancement in the area of training and, specifically, simulator-based training in 3D TEE. This training is essential, as the skill set involved in acquiring 3D data sets differs from that of two-dimensional (2D) TEE and requires users to be able to appreciate how 3D anatomic display differs from that of tomographic cross-sectional 2D imaging. This added skill set requires mental reconstruction and spatial reorientation to appreciate the added elevational dimension in frustum-based imaging and is best achieved in a simulation environment rather than the busy operating room. In this review article, the authors evaluate the functionality of a 3D TEE simulator and how simulators such as this can establish preclinical proficiency in novices in the expanding area of advanced 3D TEE imaging.

Regional Anaesthesia for Lower Extremity Amputation is Associated with Reduced Post-operative Complications Compared with General Anaesthesia.

OBJECTIVE: Primary and secondary lower extremity amputation, performed for patients with lower extremity arterial disease, is associated with increased post-operative morbidity. The aim of the study was to assess the impact of regional anaesthesia vs. general anaesthesia on post-operative pulmonary complications. METHODS: A retrospective analysis of 45 492 patients undergoing lower extremity amputation between 2005 and 2018 was conducted using data from the American College of Surgeons National Safety Quality Improvement Program database. Multivariable logistic regression was carried out to assess differences in primary outcome of post-operative pulmonary complications (pneumonia or respiratory failure requiring re-intubation) within 48 hours and 30 days after surgery between patients receiving regional (RA) or general anaesthesia (GA). Secondary outcomes included post-operative blood transfusion, septic shock, re-operation, and post-operative death within 30 days. RESULTS: Of 45 492 patients, 40 026 (88.0%) received GA and 5 466 (12.0%) RA. Patients who received GA had higher odds of developing pulmonary complications at 48 hours (2.1% vs. 1.4%; adjusted odds ratio [aOR] 1.39, 95% confidence interval [CI] 1.09 - 1.78; p = .007) and within 30 days (6.3% vs. 5.9%; aOR 1.15, 95% CI 1.09 - 1.78; p = .039). The odds of blood transfusions (aOR 1.11, 95% CI 1.02 - 1.21; p = .017), septic shock (aOR 1.29, 95% CI 1.03 - 1.60; p = .025) and re-operation (OR 1.26, 95% CI 1.03 - 1.53; p = .023) were also higher for patients who received GA vs. patients who received RA. No difference in mortality rate was observed between patients who received GA and those who received RA (5.7% vs. 7.1%; odds ratio 0.95, 95% CI 0.84 - 1.07). CONCLUSION: A statistically significant reduction in pulmonary complications was observed in patients who received RA for lower extremity amputation compared with GA.

Enhanced Post-Operative Recovery with Continuous Peripheral Nerve Block After Lower Extremity Amputation.

BACKGROUND: Despite progress in perioperative care standards, there has not been a significant risk reduction in morbidity and mortality rates of lower extremity amputations, an intermediate risk surgery performed on high risk patients. The single-shot peripheral nerve block has shown equivocal impact on postoperative course following lower extremity amputation. Hence, we assessed the potential of preemptive use of continuous catheter-based peripheral nerve block in lower extremity amputations for reduction in pulmonary complications, acute post-operative pain scores, and opioid use in post-operative period. METHODS: A retrospective review of a quality improvement project initiated in 2018 was conducted to compare outcomes amongst general anesthesia in combination with a catheter-based peripheral nerve block (catheter group) and general anesthesia alone in patients receiving lower extremity amputation. The rate of postoperative pulmonary complications was identified as a primary endpoint. The secondary outcomes assessed were acute post-operative pain scores and opioid consumption up to 48 hours. Our analysis was adjusted for potential confounding variables inclusive of demographics, medical comorbidities, type of surgical procedure and smoking status. RESULTS: Ninety-six patients were included in the study (61 in the general anesthesia group, 35 in the catheter group). After adjusting for baseline demographics, comorbidities, surgical technique and smoking status, the odds of postoperative pulmonary complications were significantly lower with catheter-based peripheral nerve block in comparison to general anesthesia alone, OR 0.11 [95% CI, 0.01- 0.88] (P = 0.048). The decrease in acute pain scores was also observed in the catheter group when compared to general anesthesia alone, OR 0.72 [95% CI, 0.56 - 0.93] (P = 0.012). Similarly, the opioid consumption was also lower in the catheter group in comparison to general anesthesia alone, OR 0.97 [95% CI, 0.95 - 0.99] (P = 0.025). CONCLUSION: Preemptive use of continuous peripheral nerve block in patients undergoing lower extremity amputation reduces the incidence of pulmonary complications, acute postoperative pain scores and narcotic use in post-operative period.

Simplified Algorithm for Evaluation of Perioperative Hypoxia and Hypotension (SALVATION): A Practical Echo-guided Approach Proposal.

Despite the valuable use of modern applications of perioperative ultrasound across multiple disciplines, there have been limitations to its implementation, restricting its impact on patient-based clinical outcomes. Point-of-care ultrasound evaluation of hypoxia and hypotension is an important tool to assess the underlying undifferentiated etiologies in a timely manner. However, there is a lack of consensus on the formal role of ultrasound during evaluation of perioperative hypoxia or hypotension. The previous ultrasound algorithms have adopted a complex technique that possibly ignore the pathophysiologic mechanisms underlying the conditions presenting in a similar fashion. The authors here propose a simple, sequential and focused multiorgan approach, applicable for the evaluation of perioperative hypotension and hypoxia in emergency scenarios. The authors believe this approach will enhance the care provided in the postanesthesia care unit, operating room, and intensive care unit.

Workflow of Ultrasound-Guided Arterial Access.

Arterial line cannulations frequently are performed in various clinical settings to facilitate hemodynamic monitoring and metabolic assessments. Palpation-guided technique generally is performed due to the superficial nature of the peripheral arteries; however, this approach may be challenging in patients with obesity, edema, and hypotension. Difficult line placements are a significant contributor of reduced operating room efficiency due to time delays seen in procedural workflow. Real-time ultrasound guidance is shown to improve success rates of arterial cannulation and reduction in multiple attempts, leading to time efficiency and less likelihood of arterial spasms or hematoma formation. In this report, the authors demonstrate the workflow of ultrasound-guided arterial line cannulation, outline the features of their institutional multi-modal training project for quality improvement, and evaluate the possible effect of the initiative on surgical delays seen with difficult line placements.

Predictors of an increased length of stay following Total Knee Arthroplasty - Survey Report.

OBJECTIVE: To find various preoperative, intraoperative and postoperative factors that predict an increased length of stay in patients following total knee arthroplasty. METHODS: The retrospective cohort study was conducted at the Aga Khan University Hospital, Karachi, and comprised record of patients regardless of gender, co-morbids and age who had undergone a unilateral or bilateral total knee arthroplasty between January 2007 and December 2015. An increased length of stay was defined as ≥75th centile (≥11 days). RESULTS: Of the 577 patients, 448(77.6%) were women. Overall, 311(53.9%) patients were aged 56-70 years. Of the total, 100(17.3%) patients stayed for at least 11 days. There was a weak but positive correlation between increasing body mass index and increased length of stay (p=0.017). Following adjusted-multivariate logistic regression analysis, the most significant predictors contributing to an increased length of stay were bilateral knee surgery, postoperative transfusion and postoperative special care unit stay (p<0.05 each). CONCLUSIONS: Bilateral total knee arthroplasty, postoperative transfusion and postoperative special care unit stay were found to be associated with an increased length of stay.

Total knee Arthroplasty: risk factors for allogeneic blood transfusions in the South Asian population.

BACKGROUND: Total knee arthroplasty (TKA) is the recommended treatment for end-stage knee osteoarthritis. Considering the various risks associated with intra and postoperative blood transfusions, better understanding is required with respect to the risk factors contributing to a greater possibility of blood transfusion during or after surgery. Although literature highlights several such factors, our study is among the first to identify these risk factors in the South Asian population which differs from other populations in several ways. METHODS: The study consists of a review of 658 patients undergoing TKA from 2005 to 2015. Data was obtained from patient medical records and was analysed using logistic regression analysis. The relationship between each predictor and the outcome variable was calculated as an Odds ratio (OR), the threshold of significance for which was p = 0.25 and p = 0.05 for univariate and multivariable analysis respectively. RESULTS: The mean age of the patient population was 63 years (78% female), 25% of whom received one or more blood transfusions. Multivariable analysis revealed 5 significant independent predictors for increased risk of blood transfusions including bilateral knee surgery (OR:5.51), preoperative anemia (OR:4.15), higher ASA (American Society of Anaesthesiologists) status (3-4) (OR:1.92), female sex (OR:3.44) and BMI (Body mass index) ≤30 (OR:1.79) while increasing co-morbidities and age (>60) were found to be insignificant. CONCLUSIONS: The factors identified for the South Asian population are largely similar to those for other populations. Identification of high risk patients will permit the application of an international multipronged approach which not only targets the modifiable risk factors but also the decision making process and blood management protocols in order to minimize the transfusion associated risks for a patient undergoing a TKA.

Pericardial effusion in an immunocompetent host- a unique presentation of histoplasmosis.

Histoplasma capsulatum infection is infrequently considered in the differential diagnoses for acute pericarditis in immunocompetent hosts when presenting with tamponade physiology, given its gradual infective nature. We describe a case of a young male presenting solely with acute pericarditis with pericardial effusion and early cardiac tamponade physiology secondary to a pulmonary histoplasmosis infection. Our patient had no pulmonary symptoms; the only pulmonary manifestation of histoplasmosis included incidental findings of subcarinal lymphadenopathy and a left lingular nodule abutting the pericardium. Given failure of symptom improvement with pericardiocentesis and first-line therapy for idiopathic/viral pericarditis, further workup of the pulmonary nodule was pursued. Histopathologic analysis of tissue showed caseating granulomas and fungal Grocott-Gömöri's methenamine silver stain revealed yeast consistent with Histoplasma species. The patient improved with itraconazole therapy. Learning objective: Pulmonary histoplasmosis has potential to present as a pericardial effusion in the immunocompetent individual. In addition to pericardiocentesis, antifungal therapy can be curative.

An Endovascular- Versus a Surgery-First Revascularization Strategy for Chronic Limb-Threatening Ischemia: A Meta-Analysis of Randomized Controlled Trials.

Timely revascularization is essential for limb salvage and to reduce mortality in patients with chronic limb-threatening ischemia (CLTI). In patients who are candidates for endovascular therapy and surgical bypass, the optimal revascularization strategy remains uncertain. Recently published randomized controlled trials (RCTs) have presented conflicting results. We conducted a trial-level meta-analysis to compare the outcomes between endovascular-first and surgery-first strategies for revascularization. PubMed, Web of Science, and the Cochrane Library were searched to identify RCTs comparing the outcomes of endovascular-first versus surgery-first strategies for revascularization in patients with CLTI. Data were pooled for major outcomes and their aggregate risk ratios (RRs) with 95% confidence intervals were calculated using a random-effects model. Kaplan-Meier curves for amputation-free survival and overall survival time were plotted using the pooled aggregated data from published curves, with their corresponding hazard ratios (HRs) and 95% confidence intervals reported for up to 5 years of follow-up. A total of 3 RCTs with 2,627 patients (1,312 endovascular-first and 1,315 surgery-first) were included in the meta-analysis. Of these, 1,864 patients (70.9%) were men and 347 (13.2%) were older than 80 years. Comparing the endovascular-first and surgery-first approaches, there was no significant difference in the overall (HR 0.92 [0.83 to 1.01], p = 0.09) or amputation-free survival (HR 0.98 [0.92 to 1.03], p = 0.42), reintervention (RR 1.24 [0.74 to 2.07], p = 0.41), major amputation, (RR 1.16 [0.87 to 1.54], p = 0.31), or therapeutic crossover (RR 0.92 [0.37 to 2.26], p = 0.85). In conclusion, data from available RCTs suggest that there is no difference in clinical outcomes between endovascular-first and surgery-first revascularization strategies for CLTI. A planned patient-level meta-analysis may provide further insight.

Distal Versus Proximal Radial Arterial Access for Percutaneous Coronary Angiography and Intervention: Updated Meta-Analysis of Randomized Controlled Trials.

Radial artery occlusion (RAO) is a major impediment to reintervention in patients who underwent proximal transradial access (p-TRA) for coronary catheterization. Distal transradial access (d-TRA) at the level of snuffbox distal to the radial artery bifurcation is a novel alternative to p-TRA. We conducted an updated meta-analysis of all available randomized controlled trials (RCTs) to compare the incidence of RAO between p-TRA and d-TRA, along with access site-related complications. PubMed, Web of Science, and Google Scholar were searched for RCTs published since 2017 to October 2023 comparing d-TRA and p-TRA for coronary angiography and/or intervention. Risk ratios (RRs) and mean differences (MDs) with 95% confidence intervals were calculated using the random-effects model for procedural and clinical outcomes for the 2 approaches. A total of 18 RCTs with 8,205 patients (d-TRA n = 4,096, p-TRA n = 4,109) were included. The risk of RAO (RR 0.31, 0.21 to 0.46, p ≤0.001) and time to hemostasis (minutes) (MD -51.18, -70.62 to -31.73, p <0.001) was significantly lower in the d-TRA group. Crossover rates (RR 2.39, 1.71 to 3.32, p <0.001), access time (minutes) (MD 0.93, 0.50 to 1.37, p <0.001), procedural pain (MD 0.46, 0.13 to 0.79, p = 0.006), and multiple puncture attempts (RR 2.13, 1.10 to 4.11, p = 0.03) were significantly higher in the d-TRA group. The use of d-TRA for coronary angiography and/or intervention is associated with a lower risk of RAO at the forearm and may preserve p-TRA site for reintervention in selective patients by reducing the incidence of RAO.