Unexpected TEE Findings During Rheumatic Triple-Valve Surgery: Incidental, Yet Impactful.

This E-Challenge highlights an incidental prebypass transesophageal echocardiographic (TEE) finding of a right atrial membrane that impacted cardiac surgical management during triple-valve surgery. Two-dimensional and advanced 3-dimensional (3D) TEE were used in real-time to assist intraoperative decision-making. The findings, clinical course, discussion of the differential diagnosis, final diagnosis, and patient management are detailed here.

Confirmatory factor analysis of the Minnesota living with heart failure questionnaire among patients following open heart surgery for valve dysfunction.

INTRODUCTION: The Minnesota Living with Heart Failure Questionnaire (MLHFQ) was designed to assess the impact of the adverse effects of heart failure (HF). Numerous reports suggest an additional third factor with the proposed third factor representing a social dimension. The purpose of this study was to use confirmatory factor analysis (CFA) to validate the factor structure of the MLWHFQ, and examine a proposed third factor structure. METHODS: Participants were 1290 individuals with open heart surgery for isolated valve repair or replacement between September 2005 and May 2016. Confirmatory factor analysis was used to assess both initial and proposed alternate factor structures. RESULTS: CFA indicated a poor fit for the original proposed 2-factor solution [root mean square error of approximation (RMSEA) = 0.116], whereas separate proposed 3-factor solutions with varying item scoring fit marginally well (RMSEA = 0.080, 0.089). The CFA suggests the existence of a third dimension, social, beyond the established original two-factor solution. Results suggest in a direct comparison of proposed social dimensions, both Garin's four item solution and Munyombwe's six-item solution provide similar results. CONCLUSIONS: Results suggest support for an additional third factor among patients undergoing isolated valve replacement surgery. We suggest given the inclusion of items important to our population, relatively strong fit indices, and correlation with the SF-12, the social dimension proposed by Munyombwe best fits our population.

End-stage renal disease and severe aortic stenosis: Does valve replacement improve one-year outcomes?

BACKGROUND: Treatment for patients with end-stage renal disease (ESRD) and severe aortic stenosis (AS) includes balloon aortic valvuloplasty (BAV), surgical (SAVR), or transcatheter (TAVR) aortic valve replacement. We compared outcomes among these strategies. METHODS: A retrospective review of patients with ESRD undergoing treatment for severe AS between 07/2007 and 06/2015 was performed at our center. Patients were classified based on treatment: BAV-only, TAVR, or SAVR. Baseline characteristics and 30-day outcomes were compared among groups. A 1-year survival analysis was performed. RESULTS: Of 85 patients, 25 (29.4%) underwent BAV, 30 (35.3%) TAVR, and 30 (35.3%) SAVR. Patients in the SAVR group, compared to the BAV or TAVR patients, were younger (63 vs. 74 vs. 71 years, P = 0.02) and had less prior stroke (3.3% vs. 12.0% vs. 30.0%, P = 0.008). While all BAV patients had NYHA class III/IV, 93.3% and 76.7% of patients had NYHA class III/IV in the TAVR and SAVR group, respectively (P = 0.001). BAV patients were less likely to have atrial fibrillation than TAVR or SAVR patients (16.0% vs. 43.3% vs. 50.0%, P = 0.03). All patients were high risk, but there was a statistical trend to lower STS scores in the SAVR group (8.6% vs. 13.5% vs. 13.5%, P = 0.08). There was no significant difference in 30-day mortality (16.7% vs. 10.0% vs. 10.0%, P = 0.74), but BAV treated patients had an increased 1-year mortality compared to those treated with TAVR or SAVR (87.0% vs. 32.0%, vs. 36.7%, P=<0.001). Independent predictors of 1-year mortality were a higher STS score (HR 1.026, 95%CI 1.002-1.051) and BAV-only strategy (BAV vs. TAVR: HR 3.961, 95%CI 1.595-9.840), but dialysis duration and type, and SAVR versus TAVR were not. CONCLUSIONS: Patients with ESRD and severe AS have a similar and higher survival with TAVR or SAVR when compared to BAV at 1-year. These results may influence patient care decisions favoring valve replacement in AS patients with ESRD. © 2016 Wiley Periodicals, Inc.

Does minimalist transfemoral transcatheter aortic valve replacement produce better survival in patients with severe chronic obstructive pulmonary disease?

OBJECTIVES: To compare outcomes after minimalist and standard transfemoral transcatheter aortic valve replacement (TF-TAVR) in patients with severe chronic obstructive pulmonary disease (COPD). BACKGROUND: TF-TAVR is increasingly performed with conscious sedation and transthoracic echocardiography guidance (minimalist). The safety/efficacy of this technique in patients with severe COPD is unknown. METHODS: We compared demographics, 30-day outcomes and 1-year survival of patients with severe COPD (FEV1% ≤50) who underwent minimalist vs. standard TF-TAVR between 2008 and 2015 at our institution. RESULTS: Of 88 patients with severe COPD, 46 underwent minimalist and 42 underwent standard TF-TAVR. There were no differences on baseline characteristics, except for more history of coronary artery bypass grafting (45.5% vs. 20.6%, P = 0.03) and less history of cerebrovascular disease (16.7% vs. 45.5%, P = 0.03) in the standard TF-TAVR. Seventeen minimalist TF-TAVR patients (41.0%) were transferred directly to the general medical ward with telemetry monitoring (without ICU stay); all standard TF-TAVR patients went to the ICU. Minimalist TF-TAVR patients had shorter procedure time (97 vs. 129 min, P < 0.001), ICU time (21.8 vs. 29.8 hr, P = 0.001) and length of stay (2 vs. 5 days, P = 0.001). There were no differences in procedure complications and 30-day mortality between groups. In our multivariate analysis, minimalist TF-TAVR (HR 0.28, 95%CI 0.08-0.97) and previous coronary revascularization (HR 0.24, 95%CI 0.09-0.65) were associated with increased 1-year survival. In contrast, moderate paravalvular leak (HR 7.73, 95%CI 1.94-30.84) was associated with decreased 1-year survival. CONCLUSION: In patients with severe COPD, Minimalist TF-TAVR results in less resource utilization and improved 1-year survival compared to standard approach. Our findings should be validated in a larger cohort of patients with severe COPD. © 2016 Wiley Periodicals, Inc.

Preclinical Evaluation of a Novel Series of Polyfluorinated Thalidomide Analogs in Drug-Resistant Multiple Myeloma.

Immunomodulatory imide drugs (IMiDs) play a crucial role in the treatment landscape across various stages of multiple myeloma. Despite their evident efficacy, some patients may exhibit primary resistance to IMiD therapy, and acquired resistance commonly arises over time leading to inevitable relapse. It is critical to develop novel therapeutic options to add to the treatment arsenal to overcome IMiD resistance. We designed, synthesized, and screened a new class of polyfluorinated thalidomide analogs and investigated their anti-cancer, anti-angiogenic, and anti-inflammatory activity using in vitro and ex vivo biological assays. We identified four lead compounds that exhibit potent anti-myeloma, anti-angiogenic, anti-inflammatory properties using three-dimensional tumor spheroid models, in vitro tube formation, and ex vivo human saphenous vein angiogenesis assays, as well as the THP-1 inflammatory assay. Western blot analyses investigating the expression of proteins downstream of cereblon (CRBN) reveal that Gu1215, our primary lead candidate, exerts its activity through a CRBN-independent mechanism. Our findings demonstrate that the lead compound Gu1215 is a promising candidate for further preclinical development to overcome intrinsic and acquired IMiD resistance in multiple myeloma.

Undersizing mitral annuloplasty alters left ventricular mechanics in a swine model of ischemic mitral regurgitation.

OBJECTIVE: Undersizing mitral annuloplasty (UMA) is a frequently used surgical repair technique to correct ischemic mitral regurgitation in patients with heart failure. In this study, we sought to test the hypothesis that downsizing the mitral annulus can adversely affect the shape and mechanics of the left ventricle inhibiting its functional recovery. METHODS: Eighteen farm swine that underwent an inferolateral myocardial infarction and developed ischemic mitral regurgitation of >2+ severity after 2 months were assigned as follows: 9 swine received an undersized mitral annuloplasty, 6 received papillary muscle approximation (PMA), and 3 animals did not receive any other intervention. Animals lived another 3 months and cardiac magnetic resonance imaging was performed before termination to assess ventricle mechanics and function. RESULTS: Ejection fraction was comparable between the 2 repair groups before surgery, but was significantly lower in UMA at 38.89% ± 7.91% versus 50.83% ± 9.04% in the PMA group (P = .0397). Animals receiving UMA had lower regional peak fractional shortening and reduced systolic and diastolic radial velocities compared with PMA and in some regions were lower than sham. Animals that underwent UMA had higher circumferential strain than sham, but lower than PMA. UMA animals have lower longitudinal strain compared to sham group and lower LV torsion than PMA. CONCLUSIONS: Undersizing the mitral annulus with an annuloplasty ring can restore valvular competence, but unphysiologically impair ventricle mechanics. Mitral valve repair strategies should focus not only on restoring valve competence, but preserving ventricle mechanics.

Papillary Muscle Approximation Reduces Systolic Tethering Forces and Improves Mitral Valve Closure in the Repair of Functional Mitral Regurgitation.

Background: Undersizing mitral annuloplasty (UMA) to repair functional mitral regurgitation lacks durability, as it forces leaflet coaptation without relieving the sub-leaflet tethering forces. In this biomechanical study, we demonstrate that papillary muscle approximation (PMA) prior to UMA can drastically relieve tethering forces and improve valve function, without the need for significant annular downsizing. Methods: An ex vivo model of functional mitral regurgitation (FMR) was used, in which pig mitral valves were geometrically perturbed to induce FMR, and the repairs were performed. Nine pig mitral valves were studied as follows: normal(baseline), functional mitral regurgitation (FMR), true-sized annuloplasty to 30mm (TSR), and undersized annuloplasty to 26mm (DSR); and concomitant papillary muscle approximation (PMA) at both ring sizes. Mitral regurgitation, valve kinematics, and chordal forces were measured and compared between groups. Results: FMR geometry induced a 16.31±7.33% regurgitant fraction, compared to none at baseline. 30mm/TSR reduced regurgitation to 6.05±5.63% and a 26mm/DSR to 5.06±6.76%. Addition of papillary muscle approximation prior to either rings, reduced regurgitation to 3.87±6.79% with the true sized ring (TSR+PMA), and 3.71±6.25% with the downsized ring (DSR+PMA). Peak anterior and posterior marginal chordal forces were elevated to 0.09±0.1N and 0.12±0.1N respectively with FMR, which were not reduced by annuloplasty of either sizes. Addition of PMA, reduced the forces significantly to 0.23±0.02N and 0.51±0.04N. Conclusion: This biomechanical study, demonstrates that papillary muscle approximation relieves tethering forces and when added to annuloplasty, and mobilizes the leaflets to achieve a good valve closure. Such a result could be achieved without the need for extensive annular downsizing.

Diagnostic peritoneal lavage remains a valuable adjunct to modern imaging techniques.

BACKGROUND: Continuing improvements in computerized tomography scan technology and widespread acceptance of focused abdominal sonography for trauma (FAST) have prompted the suggestion that diagnostic peritoneal lavage (DPL) is obsolete. This sentiment, coupled with decreasing resident familiarity with DPL, has led to a poor understanding of the modern indications for DPL and no clear guidelines. We hypothesized that, while its indications may have changed, DPL remains essential in the rapid, effective triage of the trauma patient. METHODS: We queried our Level I trauma center's trauma registry from January 1996 through August 2006 for patients who underwent a DPL as part of their initial evaluation. Specific variables investigated were indications for or results of DPL, performance of a laparotomy in the first 24 hours, and operative findings. RESULTS: Six hundred twenty-seven patients underwent DPL (145 positive, 482 negative). Although the accuracy of DPL for predicting therapeutic laparotomy for all patients was only 77%, in the subset of hemodynamically unstable patients (of which only 46% had a positive FAST), it was 100%. Conversely, only 7% of all patients with negative DPL subsequently had a therapeutic laparotomy, with only 5% in the subset of stab wounds. CONCLUSION: DPL continues to be a vital tool in the evaluation of the trauma patient. A positive test in the hemodynamically unstable patient with potential multisystem trauma allows for expeditious intervention. A negative test in abdominal stab wounds supports observation and early subsequent discharge. Our current guidelines continue to emphasize the complimentary roles of DPL, FAST, and computerized tomography scan in the trauma bay.

Arachidonic acid in postshock mesenteric lymph induces pulmonary synthesis of leukotriene B4.

Mesenteric lymph is the mechanistic link between splanchnic hypoperfusion and acute lung injury (ALI), but the culprit mediator(s) remains elusive. Previous work has shown that administration of a phospholipase A(2) (PLA(2)) inhibitor attenuated postshock ALI and also identified a non-ionic lipid within the postshock mesenteric lymph (PSML) responsible for polymorphonuclear neutrophil (PMN) priming. Consequently, we hypothesized that gut-derived leukotriene B(4) (LTB(4)) is a key mediator in the pathogenesis of ALI. Trauma/hemorrhagic shock (T/HS) was induced in male Sprague-Dawley rats and the mesenteric duct cannulated for lymph collection/diversion. PSML, arachidonic acid (AA), and a LTB(4) receptor antagonist were added to PMNs in vitro. LC/MS/MS was employed to identify bioactive lipids in PSML and the lungs. T/HS increased AA in PSML and increased LTB(4) and PMNs in the lung. Lymph diversion decreased lung LTB(4) by 75% and PMNs by 40%. PSML stimulated PMN priming (11.56 +/- 1.25 vs. 3.95 +/- 0.29 nmol O(2)(-)/min; 3.75 x 10(5) cells/ml; P < 0.01) that was attenuated by LTB(4) receptor blockade (2.64 +/- 0.58; P < 0.01). AA stimulated PMNs to produce LTB(4), and AA-induced PMN priming was attenuated by LTB(4) receptor antagonism. Collectively, these data indicate that splanchnic ischemia/reperfusion activates gut PLA(2)-mediated release of AA into the lymph where it is delivered to the lungs, provoking LTB(4) production and subsequent PMN-mediated lung injury.

Video and accelerometer-based motion analysis for automated surgical skills assessment.

PURPOSE: Basic surgical skills of suturing and knot tying are an essential part of medical training. Having an automated system for surgical skills assessment could help save experts time and improve training efficiency. There have been some recent attempts at automated surgical skills assessment using either video analysis or acceleration data. In this paper, we present a novel approach for automated assessment of OSATS-like surgical skills and provide an analysis of different features on multi-modal data (video and accelerometer data). METHODS: We conduct a large study for basic surgical skill assessment on a dataset that contained video and accelerometer data for suturing and knot-tying tasks. We introduce "entropy-based" features-approximate entropy and cross-approximate entropy, which quantify the amount of predictability and regularity of fluctuations in time series data. The proposed features are compared to existing methods of Sequential Motion Texture, Discrete Cosine Transform and Discrete Fourier Transform, for surgical skills assessment. RESULTS: We report average performance of different features across all applicable OSATS-like criteria for suturing and knot-tying tasks. Our analysis shows that the proposed entropy-based features outperform previous state-of-the-art methods using video data, achieving average classification accuracies of 95.1 and 92.2% for suturing and knot tying, respectively. For accelerometer data, our method performs better for suturing achieving 86.8% average accuracy. We also show that fusion of video and acceleration features can improve overall performance for skill assessment. CONCLUSION: Automated surgical skills assessment can be achieved with high accuracy using the proposed entropy features. Such a system can significantly improve the efficiency of surgical training in medical schools and teaching hospitals.

Pathological Remodeling of Mitral Valve Leaflets from Unphysiologic Leaflet Mechanics after Undersized Mitral Annuloplasty to Repair Ischemic Mitral Regurgitation.

Background Undersized ring annuloplasty is a commonly used surgical repair for ischemic mitral regurgitation, in which annular downsizing corrects regurgitation, but alters valve geometry and elevates tissue stresses. In this study, we investigated if unphysiological leaflet kinematics after annuloplasty might cause pathogenic biological remodeling of the mitral valve leaflets, and if preserving physiologic leaflet kinematics with a better technique can moderate such adverse remodeling. Methods and Results Twenty-nine swine were induced with ischemic mitral regurgitation, and survivors were assigned to groups: 7 underwent annuloplasty, 12 underwent annuloplasty with papillary-muscle approximation, 6 underwent papillary-muscle approximation, and 3 were sham controls. Pre-and post-surgery leaflet kinematics were measured, and valve tissue was explanted after 3 months to assess biological changes. Anterior leaflet excursion was unchanged across groups, but persistent tethering was observed with annuloplasty. Posterior leaflet was vertically immobile after annuloplasty, better mobile with the combined approach, and substantially ( P=0.0028) mobile after papillary-muscle approximation. Procollagen-1 was higher in leaflets from annuloplasty compared with the other groups. Heat shock protein-47 and lysyl oxidase were higher in groups receiving annuloplasty compared with sham. α- SMA was elevated in leaflets from animals receiving an annuloplasty, indicating activation of quiescent valve interstitial cells, paralleled by elevated transforming growth factor-ß expression. Conclusions This is the first study to demonstrate that surgical valve repairs that impose unphysiological leaflet mechanics have a deleterious, pathological impact on valve biology. Surgeons may need to consider restoring physiologic leaflet stresses as well as valve competence, while also exploring pharmacological methods to inhibit the abnormal signaling cascades.

Transcatheter Mitral Valve Repair Therapies: Evolution, Status and Challenges.

Mitral regurgitation is a common cardiac valve lesion, developing from primary lesions of the mitral valve or secondary to cardiomyopathies. Moderate or higher severity of mitral regurgitation imposes significant volume overload on the left ventricle, causing permanent structural and functional deterioration of the myocardium and heart failure. Timely correction of regurgitation is essential to preserve cardiac function, but surgical mitral valve repair is often delayed due to the risks of open heart surgery. Since correction of mitral regurgitation can provide symptomatic relief and halt progressive cardiac dysfunction, transcatheter mitral valve repair technologies are emerging as alternative therapies. In this approach, the mitral valve is repaired either with sutures or implants that are delivered to the native valve on catheters introduced into the cardiovascular system under image guidance, through small vascular or ventricular ports. Several transcatheter mitral valve technologies are in development, but limited clinical success has been achieved. In this review, we present a historical perspective of mitral valve repair, review the transcatheter technologies emerging from surgical concepts, the challenges they face in achieving successful clinical application, and the increasing rigor of safety and durability standards for new transcatheter valve technologies.

A Swine Model of Percutaneous Intracoronary Ethanol Induced Acute Myocardial Infarction and Ischemic Mitral Regurgitation.

Ischemic mitral regurgitation (IMR) is a frequent complication after a myocardial infarction (MI), which doubles mortality. Transcatheter mitral repairs are emerging as alternative treatment options to open heart surgery for IMR, but animal models to test them are lacking. We report a percutaneous swine model of IMR. Seventeen swine were randomized to (group 1, n = 12) MI causing IMR, and (group 2, n = 5) controls. In group 1, MI was induced via percutaneous ethanol injection into the obtuse marginal branches of the left circumflex artery, resulting in ST elevating myocardial infarction. Nine animals were survived to 8-10 weeks with weekly echocardiograms and three swine were survived to 16-20 weeks with MRI at termination. In group 1 animals, average IMR fraction at termination was 26.6 ± 2.3% in the echo group, and 24.51 ± 0.41% in the MRI group. None of the animals in group 2 had IMR. Left ventricular dysfunction and significant dilatation were evident in group 1 animals, compared to the controls. In conclusion, a reproducible model of IMR is reported for use in pre-clinical testing of new mitral technologies.

The Racial Paradox in Multiarterial Conduit Utilization for Coronary Artery Bypass Grafting.

BACKGROUND: It has been established that outcomes for black patients undergoing coronary artery bypass graft surgery (CABG) are inferior to those of their white counterparts. The purpose of this study was to determine (1) whether rates of multiarterial grafting are different among black patients and white patients, and (2) whether racial differences exist in postoperative outcomes after accounting for grafting strategy. METHODS: A retrospective review of black patients (n = 2,810) and white patients (n = 13,569) who underwent isolated, primary CABG from January 2002 to June 2014 at a US academic institution was performed. A modified predicted risk of mortality (M-PROM) score was calculated for each patient using all The Society of Thoracic Surgeons variables for CABG excluding race. Multivariable linear, logistic, and Cox regression analyses were used to assess between-group differences, adjusted for M-PROM. RESULTS: Overall, 16,379 patients underwent CABG, and 2,441 (14.9%) received more than one arterial graft. When adjusted for M-PROM, the odds of blacks undergoing multiarterial CABG were 10% greater than for whites (p = 0.05). Blacks had worse inhospital outcomes, including higher odds of stroke (odds ratio 2.41, 95% confidence interval [CI]: 1.80 to 3.25) and prolonged intubation (odds ratio 2.01, 95% CI: 1.77 to 2.28). The increase in postoperative complications did not translate to a difference in inhospital mortality (p = 0.10) between racial cohorts. Moreover, among patients who underwent multiarterial grafting strategies, blacks had a hazard of mortality that was 34% higher (95% CI: 22% to 51%)) than that of their white counterparts. Among black patients, those who underwent multiarterial grafting strategies showed better long-term survival than those undergoing single grafting strategies (hazard ratio 0.86, 95% CI: 0.78 to 0.96). CONCLUSIONS: Despite similar rates of arterial grafting for black patients and white patients in this large single-center cohort, black patients continued to have significantly worse late survival when compared with white patients. Continued evaluation as to the causes of this disparity is warranted.

Should We Perform Carotid Doppler Screening Before Surgical or Transcatheter Aortic Valve Replacement?

BACKGROUND: Screening for internal carotid artery stenosis (ICAS) with Doppler ultrasound is commonly used before cardiovascular surgery. Nevertheless, the relationship between ICAS and procedure-related stroke in isolated aortic valve replacement is unclear. METHODS: We retrospectively reviewed patients with artery stenosis who underwent ICAS screening before surgical (SAVR) or transcatheter aortic valve replacement (TAVR) between January 2007 and August 2014. Logistic regression models were used to determine the relation between post-procedure stroke and total (sum of left and right ICAS) and maximal unilateral ICAS. Age, sex, history of atrial fibrillation, cerebrovascular disease and diabetes, left ventricular ejection fraction, and procedure type were considered as covariates. Two-subgroup analyses were performed in patients who underwent TAVR and SAVR, adjusting for procedure specific details. RESULTS: A total of 996 patients underwent ICAS screening before TAVR (n = 467) or SAVR (n = 529). The prevalence of at least ≥70% ICAS was 5.2% (n = 52) and incidence of 30-day stroke was 3.4% (n = 34). Eight patients who underwent carotid intervention before valve replacement and 6 patients with poor Doppler images were excluded from the final analysis. We found no statistically significant association between stroke and either the total or maximal unilateral ICAS for all patients (p = 0.13 and p = 0.39, respectively) or those undergoing TAVR (p = 0.27 and p = 0.63, respectively) or SAVR (p = 0.21 and p = 0.36, respectively). CONCLUSIONS: We found no statistically significant association between ICAS severity procedure-related stroke after aortic valve replacement. This suggests that universal carotid Doppler screening before isolated TAVR or SAVR is unnecessary.

Bioactivity of postshock mesenteric lymph depends on the depth and duration of hemorrhagic shock.

Mesenteric hypoperfusion due to circulatory shock is a key event in the pathogenesis of subsequent distant organ injury. Postshock mesenteric lymph (PSML) has been shown to contain proinflammatory mediators elaborated from the ischemic gut. We hypothesize that the relative bioactivity of PSML depends on the depth and duration of circulatory shock. To first determine the timing of PSML bioactivity, we subjected rats to hemorrhagic shock (30 mm Hg x 45 min) and then resuscitation with 50 vol% of shed blood and normal saline (4x shed blood) over 2 h. Mesenteric lymph was collected hourly up to 6 h after shock. Superoxide release was measured from human neutrophils (polymorphonuclear neutrophils [PMNs]) incubated with lymph fractions collected from each of the hourly time points. Rats were then subjected to four different shock variations: (1) 30 mm Hg x 45 min, (2) 30 mm Hg x 15 min, (3) 45 mm Hg x 45 min, and (4) 45 mm Hg x 15 min, and were resuscitated. PSML flow depends on depth of shock, but not duration of shock or resuscitation volume. Maximal PSML bioactivity, as measured by PMN priming for the respiratory burst, occurred during the third postshock hour, which correlated with peak lymph flow rate. PSML bioactivity was greatest with 30 mm Hg x 45 min, followed by 30 mm Hg x 15 min, 45 mm Hg x 45 min, and 45 mm Hg x 15 min. Hemorrhagic shock provokes the release of bioactive agents in PSML that is dependent on both depth and duration of shock.

Automated video-based assessment of surgical skills for training and evaluation in medical schools.

PURPOSE: Routine evaluation of basic surgical skills in medical schools requires considerable time and effort from supervising faculty. For each surgical trainee, a supervisor has to observe the trainees in person. Alternatively, supervisors may use training videos, which reduces some of the logistical overhead. All these approaches however are still incredibly time consuming and involve human bias. In this paper, we present an automated system for surgical skills assessment by analyzing video data of surgical activities. METHOD: We compare different techniques for video-based surgical skill evaluation. We use techniques that capture the motion information at a coarser granularity using symbols or words, extract motion dynamics using textural patterns in a frame kernel matrix, and analyze fine-grained motion information using frequency analysis. RESULTS: We were successfully able to classify surgeons into different skill levels with high accuracy. Our results indicate that fine-grained analysis of motion dynamics via frequency analysis is most effective in capturing the skill relevant information in surgical videos. CONCLUSION: Our evaluations show that frequency features perform better than motion texture features, which in-turn perform better than symbol-/word-based features. Put succinctly, skill classification accuracy is positively correlated with motion granularity as demonstrated by our results on two challenging video datasets.

Predicted Risk of Mortality, Transfusion, and Postoperative Outcomes in Isolated Primary Valve Operations.

BACKGROUND: Transfusion has been linked with increased postoperative morbidity and death after cardiac operations. The purpose of this study was to determine the associations among The Society of Thoracic Surgeons Predicted Risk of Mortality (PROM), transfusion, and postoperative outcomes in patients who underwent isolated primary valve operations. METHODS: A retrospective review of the local Society of Thoracic Surgeons database of 1,575 adults undergoing isolated primary valve operations from 2003 to 2013 at a United States academic center was performed. Patients were compared by their postoperative transfusion status (NONE vs TRANS) and by PROM. Taking into account procedure type and preoperative hemoglobin, three-step multiple linear or logistic regression analyses were performed to assess (1) the influence of PROM on postoperative outcomes, (2) influence of PROM on transfusion, and (3) influence of PROM and transfusion on postoperative outcomes. RESULTS: Of 1,575 patients studied, 1,245 (79%) received transfusions. The mean PROM was 1.2% (95% confidence interval [CI], 1.1 to 1.3) for patients in the NONE group, and was 2.7% (95% CI, 2.6 to 2.9) for the TRANS group. The correlation between PROM and total red blood cell units transfused was r = 0.31 (p < 0.0001). Patients with a PROM of 4% to 8% (odds ratio [OR], 2.10; 95% CI, 1.28 to 3.45) and exceeding 8% (OR 3.80, 95% CI, 1.35 to 10.68) were more likely to receive transfusions than the low-risk (<4%) PROM stratum. For each percentage increase in PROM, the odds of transfusion increased by 27% (95% CI, 16% to 39%), controlling for procedure type and preoperative hemoglobin. There were no 30-day deaths in the NONE group, and rates of stroke, renal failure, and mediastinitis were lower. Composite event rates increased with increasing PROM (OR, 1.39; 95% CI, 1.19 to 1.63), with TRANS patients consistently showing a higher risk of major adverse cardiac events than NONE patients (OR, 7.47; 95% CI, 2.08 to 26.80). CONCLUSIONS: Increased PROM yielded higher risks of transfusion. Postoperative outcomes were worse in patients who received a transfusion. This study suggests that the association between transfusion and clinical outcomes may be partly explained by the higher PROM among patients who ultimately received transfusions.

Swine (Sus scrofa) as a Model of Postinfarction Mitral Regurgitation and Techniques to Accommodate Its Effects during Surgical Repair.

Mitral regurgitation (MR) is a common heart-valve lesion after myocardial infarction in humans. Because it is considered a risk factor for accelerated heart failure and death, various surgical approaches and catheter-based devices to correct it are in development. Lack of a reproducible animal model of MR after myocardial infarction and reliable techniques to perform open-heart surgery in these diseased models led to the use of healthy animals to test new devices. Thus, most devices that are deemed safe in healthy animals have shown poor results in human efficacy studies, hampering progress in this area of research. Here we report our experience with a swine model of postinfarction MR, describe techniques to induce regurgitation and perform open-heart surgery in these diseased animals, and discuss our outcomes, complications, and solutions.

Transcatheter Aortic Valve Replacement: Current Technology and Future Directions.

Transcatheter aortic valve replacement as an alternative to open surgical repair is rapidly becoming more used in high-risk patients with aortic stenosis. Transcatheter aortic valve replacement offers the benefit of being much less invasive than traditional surgical repair and has evolved as a therapeutic option for patients with prohibitive surgical risk or those deemed surgically inoperable. Nevertheless, despite its potential to mitigate risk in this frail population, it comes with its own unique set of complications. Technological advancements in valve structure, function, and delivery have and continue to attempt to minimize these risks. This review aims to summarize current advancements in transcatheter aortic valve replacement technology while also introducing areas of future direction in this exciting new field.