Evaluating Educational Outcomes Using Patient Outcomes of New Surgeons Performing Partial Colectomy Compared to Cholecystectomy.

PURPOSE: Despite ongoing efforts to improve surgical education, surgical residents face gaps in their training. However, it is unknown if differences in the training of surgeons are reflected in the patient outcomes of those surgeons once they enter practice. This study aimed to compare the patient outcomes among new surgeons performing partial colectomy-a common procedure for which training is limited-and cholecystectomy-a common procedure for which training is robust. METHOD: The authors retrospectively analyzed all adult Medicare claims data for patients undergoing inpatient partial colectomy and inpatient cholecystectomy between 2007 and 2018. Generalized additive mixed models were used to investigate the associations between surgeon years in practice and risk-adjusted rates of 30-day serious complications and death for patients undergoing partial colectomy and cholecystectomy. RESULTS: A total of 14,449 surgeons at 4,011 hospitals performed 340,114 partial colectomy and 355,923 cholecystectomy inpatient operations during the study period. Patients undergoing a partial colectomy by a surgeon in their 1st vs 15th year of practice had higher rates of serious complications (5.22% [95% CI, 4.85%-5.60%] vs 4.37% [95% CI, 4.22%-4.52%]; P < .01) and death (3.05% [95% CI, 2.92%-3.17%] vs 2.83% [95% CI, 2.75%-2.91%]; P < .01). Patients undergoing a cholecystectomy by a surgeon in their 1st vs 15th year of practice had similar rates of 30-day serious complications (4.11% vs 3.89%; P = .11) and death (1.71% vs 1.70%; P = .93). CONCLUSIONS: Patients undergoing partial colectomy faced a higher risk of serious complications and death when the operation was performed by a new surgeon compared to an experienced surgeon. Conversely, patient outcomes following cholecystectomy were similar for new and experienced surgeons. More attention to partial colectomy during residency training may benefit patients.

Association of Surgical Resident Competency Ratings With Patient Outcomes.

PURPOSE: Accurate assessment of clinical performance is essential to ensure graduating residents are competent for unsupervised practice. The Accreditation Council for Graduate Medical Education milestones framework is the most widely used competency-based framework in the United States. However, the relationship between residents' milestones competency ratings and their subsequent early career clinical outcomes has not been established. It is important to examine the association between milestones competency ratings of U.S. general surgical residents and those surgeons' patient outcomes in early career practice. METHOD: A retrospective, cross-sectional study was conducted using a sample of national Medicare claims for 23 common, high-risk inpatient general surgical procedures performed between July 1, 2015, and November 30, 2018 (n = 12,400 cases) by nonfellowship-trained U.S. general surgeons. Milestone ratings collected during those surgeons' last year of residency (n = 701 residents) were compared with their risk-adjusted rates of mortality, any complication, or severe complication within 30 days of index operation during their first 2 years of practice. RESULTS: There were no associations between mean milestone competency ratings of graduating general surgery residents and their subsequent early career patient outcomes, including any complication (23% proficient vs 22% not yet proficient; relative risk [RR], 0.97, [95% CI, 0.88-1.08]); severe complication (9% vs 9%, respectively; RR, 1.01, [95% CI, 0.86-1.19]); and mortality (5% vs 5%; RR, 1.07, [95% CI, 0.88-1.30]). Secondary analyses yielded no associations between patient outcomes and milestone ratings specific to technical performance, or between patient outcomes and composites of operative performance, professionalism, or leadership milestones ratings ( P ranged .32-.97). CONCLUSIONS: Milestone ratings of graduating general surgery residents were not associated with the patient outcomes of those surgeons when they performed common, higher-risk procedures in a Medicare population. Efforts to improve how milestones ratings are generated might strengthen their association with early career outcomes.

Pragmatic Mentoring Strategies for the Busy Surgeon Scientist.

OBJECTIVE: The value of research mentorship in academic medicine is well-recognized, yet there is little practical advice for how to develop and sustain effective mentoring partnerships. Gaining research skill and mentorship is particularly critical to success in academic surgery, yet surgeon scientists are challenged in their mentorship efforts by time constraints and lack of education on how to mentor. To address this gap, this study explored the strategies that award-winning faculty mentors utilize in collaborating with their medical student mentees in research. DESIGN, SETTING, AND PARTICIPANTS: For this qualitative study, the authors invited physician recipients of an institution-wide mentorship award to participate in individual, semi-structured interviews during July and August 2018. Following interview transcription, the authors independently coded the text and collaboratively identified common mentoring strategies and practices via a process of thematic analysis. RESULTS: Nine physician mentors, representing a mix of genders, medical specialties and types of research (basic science, clinical, translational, and health services), participated in interviews. The authors identified 12 strategies and practices from the interview transcripts that fell into 5 categories: Initiating the partnership; Determining the research focus; Providing project oversight; Developing mentee research competence; and Supporting mentee self-efficacy. CONCLUSION: Award-winning mentors employ a number of shared strategies when mentoring medical trainees in research. These strategies can serve as a guide for academic surgeons who wish to improve their research mentoring skills.

Representativeness of Workplace-Based Operative Performance Assessments for Resident Operative Experience.

OBJECTIVE: Workplace-based assessment is increasingly prevalent in surgical education, especially for assessing operative skill. With current implementations, not all observed clinical performances are assessed, in part because trainees often have discretion about when they seek assessment. As a result, these samples of observed operative performances may not be representative of the full breadth of experience of surgical trainees. Therefore, analyses of these samples may be biased. We aimed to benchmark patterns of procedures logged in the SIMPL operative performance assessment system against records of trainee experience in Accreditation Council for Graduate Medical Education (ACGME) case logs. DESIGN: We analyzed SIMPL longitudinal intraoperative performance assessments from categorical trainees in US general surgery residency programs. We compared overall patterns of how procedures are logged in SIMPL and in ACGME case logs using a Pearson correlation, and we examined differences in how individual procedures are logged in each system using Fisher's exact test. RESULTS: Total procedure frequency from the SIMPL dataset was strongly correlated with total procedure frequency from ACGME case logs (r = 0.86, 95% CI 0.80-0.90). A subset of these procedures (10 of 116 procedures) was logged more frequently in the SIMPL dataset. These 10 procedures accounted for 56% of SIMPL observations and 30% of ACGME logged cases. Case complexity was comparable for assessments initiated by residents and faculty. CONCLUSIONS: Samples of intraoperative performance ratings gathered using the SIMPL application largely resemble ACGME case logs. There is no evidence to indicate that residents preferentially select fewer complex cases for assessment.

Surgical Trainee Performance and Alignment With Surgical Program Director Expectations.

OBJECTIVE: To examine the alignment between graduating surgical trainee operative performance and a prior survey of surgical program director expectations. BACKGROUND: Surgical trainee operative training is expected to prepare residents to independently perform clinically important surgical procedures. METHODS: We conducted a cross-sectional observational study of US general surgery residents' rated operative performance for Core general surgery procedures. Residents' expected performance on those procedures at the time of graduation was compared to the current list of Core general surgery procedures ranked by their importance for clinical practice, as assessed via a previous national survey of general surgery program directors. We also examined the frequency of individual procedures logged by residents over the course of their training. RESULTS: Operative performance ratings for 29,885 procedures performed by 1861 surgical residents in 54 general surgery programs were analyzed. For each Core general surgery procedure, adjusted mean probability of a graduating resident being deemed practice-ready ranged from 0.59 to 0.99 (mean 0.90, standard deviation 0.08). There was weak correlation between the readiness of trainees to independently perform a procedure at the time of graduation and that procedure's historical importance to clinical practice ( p = 0.22, 95% confidence interval 0.01-0.41, P = 0.06). Residents also continue to have limited opportunities to learn many procedures that are important for clinical practice. CONCLUSION: The operative performance of graduating general surgery residents may not be well aligned with surgical program director expectations.

How Do Programs Measure Resident Performance? A Multi-Institutional Inventory of General Surgery Assessments.

OBJECTIVE: To perform an inventory of assessment tools in use at surgical residency programs and their alignment with the Milestone Competencies. DESIGN: We conducted an inventory of all assessment tools from a sample of general surgery training programs participating in a multi-center study of resident operative development in the United States. Each instrument was categorized using a data extraction tool designed to identify criteria for effective assessment in competency based education and according to which Milestone Competency was being evaluated. Tabulations of each category were then analyzed using descriptive statistics. Interviews with program directors and assessment coordinators were conducted to understand each instrument's intended use within each program. SETTING: Multi-institutional review of general surgery assessment programs. PARTICIPANTS: We identified assessment tools used by 10 general surgery programs during the 2019 to 2020 academic year. Programs were selected from a cohort already participating in a separate research study of resident operative development in the United States. RESULTS: We identified 42 unique assessment tools used. Each program used an average of 7.2 (range 4-13) unique assessment instruments to measure performance, of which only 5 (11.9%) were used by at least 1 other program in our sample. Of all assessments, 59.5% were used monthly or less frequently. The majority (66.7%) of instruments were retrospective global assessments, rather than discrete observed performances. There were 4 (9.5%) instruments with established reliability or validity evidence. Across programs there was also significant variation in the volume of assessment used to evaluate residents, with the median total number of evaluations/trainee across all Milestone Competencies being 217 (IQR 78) per year. Patient care was the most frequently evaluated Milestone Competency. CONCLUSIONS: General surgical assessment systems predominantly employ non-standardized global assessment tools that lack reliability or validity evidence. This variability makes it challenging to interpret and compare competency standards across programs. A standardized assessment toolkit with established reliability and validity evidence would allow training programs to measure the competence of their trainees more uniformly and understand where improvements in our training system can be made.

Novel method to link surgical trainee performance data to patient outcomes.

BACKGROUND: A significant roadblock in surgical education research has been the inability to compare trainee performance to the outcomes of those surgeons after they enter independent practice. We describe the feasibility of an innovative method to link trainee performance data with patient outcomes. METHODS: We extracted surgeon NPI numbers from Medicare claims data for common general surgery procedures between 2007 and 2017. Next, American Board of Surgery (ABS) trainee performance data was cross-referenced with additional resources to supplement NPI data. The patient and trainee datasets were linked using NPI number and a linkage rate was calculated. RESULTS: We identified 12,952 unique surgeons in the Medicare file. Medicare surgeons were matched with ABS records by NPI number, with 96.2% (n = 12,460) of surgeons linked successfully. CONCLUSIONS: We demonstrated a novel process to link patient outcomes to trainee performance. This innovation can enable future research investigating the relationship between surgical trainee performance and patient outcomes in independent practice.

Using Natural Language Processing to Automatically Assess Feedback Quality: Findings From 3 Surgical Residencies.

PURPOSE: Learning is markedly improved with high-quality feedback, yet assuring the quality of feedback is difficult to achieve at scale. Natural language processing (NLP) algorithms may be useful in this context as they can automatically classify large volumes of narrative data. However, it is unknown if NLP models can accurately evaluate surgical trainee feedback. This study evaluated which NLP techniques best classify the quality of surgical trainee formative feedback recorded as part of a workplace assessment. METHOD: During the 2016-2017 academic year, the SIMPL (Society for Improving Medical Professional Learning) app was used to record operative performance narrative feedback for residents at 3 university-based general surgery residency training programs. Feedback comments were collected for a sample of residents representing all 5 postgraduate year levels and coded for quality. In May 2019, the coded comments were then used to train NLP models to automatically classify the quality of feedback across 4 categories (effective, mediocre, ineffective, or other). Models included support vector machines (SVM), logistic regression, gradient boosted trees, naive Bayes, and random forests. The primary outcome was mean classification accuracy. RESULTS: The authors manually coded the quality of 600 recorded feedback comments. Those data were used to train NLP models to automatically classify the quality of feedback across 4 categories. The NLP model using an SVM algorithm yielded a maximum mean accuracy of 0.64 (standard deviation, 0.01). When the classification task was modified to distinguish only high-quality vs low-quality feedback, maximum mean accuracy was 0.83, again with SVM. CONCLUSIONS: To the authors' knowledge, this is the first study to examine the use of NLP for classifying feedback quality. SVM NLP models demonstrated the ability to automatically classify the quality of surgical trainee evaluations. Larger training datasets would likely further increase accuracy.

How Many Attempts Are Needed to Achieve General Surgery Board Certification?

OBJECTIVE: Surgical trainees are subject to pressure from variety of stakeholders to secure board certification from the American Board of Surgery (ABS). To meet these expectations, trainees must pass a written qualifying exam (QE) and an oral certifying exam (CE) within 7 years of completing general surgery residency. Board certification outcomes for candidates who fail either the QE or CE examination are not well characterized, but this information could help candidates, policymakers, and other stakeholders make informed decisions about how to respond to examination failure. METHODS: We retrospectively examined ABS records for all surgeons who completed general surgery residency from 2000 to 2013 and attempted general surgery board certification. RESULTS: Among 14,483 surgeons who attempted general surgery certification, 13,566 (94%) passed both the QE and CE within the 7-year certification window. Of those who did ultimately obtain certification, 97% passed the QE within 2 attempts and 97% passed the CE within 2 attempts. For those who failed either the QE or the CE twice, 67% ultimately obtained certification. CONCLUSIONS: Most surgeons who obtained ABS general surgery board certification did so within 2 attempts at each board examination. Candidates who fail either examination twice are less likely to achieve board certification.

Is Initial Board Certification Associated With Better Early Career Surgical Outcomes?

OBJECTIVE: To determine if initial American Board of Surgery certification in general surgery is associated with better risk-adjusted patient outcomes for Medicare patients undergoing partial colectomy by an early career surgeon. BACKGROUND: Board certification is a voluntary commitment to professionalism, continued learning, and delivery of high-quality patient care. Not all surgeons are certified, and some have questioned the value of certification due to limited evidence that board-certified surgeons have better patient outcomes. In response, we examined the outcomes of certified versus noncertified early career general surgeons. METHODS: We identified Medicare patients who underwent a partial colectomy between 2008 and 2016 and were operated on by a non-subspecialty trained surgeon within their first 5 years of practice. Surgeon certification status was determined using the American Board of Surgery data. Generalized linear mixed models were used to control for patient-, procedure-, and hospital-level effects. Primary outcomes were the occurrence of severe complications and occurrence of death within 30 days. RESULTS: We identified 69,325 patients who underwent a partial colectomy by an early career general surgeon. The adjusted rate of severe complications after partial colectomy by certified (n = 4239) versus noncertified (n = 191) early-career general surgeons was 9.1% versus 10.7% (odds ratio 0.83, P = 0.03). Adjusted mortality rate for certified versus noncertified early-career general surgeons was 4.9% versus 6.1% (odds ratio 0.79, P = 0.01). CONCLUSION: Patients undergoing partial colectomy by an early career general surgeon have decreased odds of severe complications and death when their surgeon is board certified.

The reliability of resident self-evaluation of operative performance.

BACKGROUND: Self-assessment is critical to professional self-regulation yet many trainees may not reliably self-evaluate. We examine the gap between resident and faculty perceptions of trainee operative performance and contributing factors. METHODS: Surgery resident and faculty evaluations of trainee performance were collected from 14 academic institutions using smartphone-based performance assessments. Differences in resident/faculty ratings evaluating the same procedure were analyzed using descriptive statistics and Bayesian mixed models. RESULTS: Of 7382 evaluations, 46% trainees and faculty performance ratings were discrepant (r = 0.47), with 80% residents rating themselves lower than faculty in those cases. This gap existed regardless of case complexity and widened as trainees gained experience. Trainees who overrated themselves had the lowest mean performance scores from faculty. CONCLUSION: Half of residents perceived their performance differently from faculty, and this difference widened for senior residents. Future focus should be to provide opportunity for trainees to improve skills to reliably assess themselves before graduation.

Trainee Autonomy in Minimally Invasive General Surgery in the United States: Establishing a National Benchmark.

OBJECTIVE: Minimally invasive surgery (MIS) is an integral component of General Surgery training and practice. Yet, little is known about how much autonomy General Surgery residents achieve in MIS procedures, and whether that amount is sufficient. This study aims to establish a contemporary benchmark for trainee autonomy in MIS procedures. We hypothesize that trainees achieve progressive autonomy, but fail to achieve meaningful autonomy in a substantial percentage of MIS procedures prior to graduation. SETTING/PARTICIPANTS: Fifty General Surgery residency programs in the United States, from September 1, 2015 to March 19, 2020. All Categorical General Surgery Residents and Attending Surgeons within these programs were eligible. DESIGN: Data were collected prospectively from attending surgeons and categorical General Surgery residents. Trainee autonomy was assessed using the 4-level Zwisch scale (Show and Tell, Active Help, Passive Help, and Supervision Only) on a smartphone application (SIMPL). MIS procedures included all laparoscopic, thoracoscopic, endoscopic, and endovascular/percutaneous procedures performed by residents during the study. Primary outcomes of interest were "meaningful autonomy" rates (i.e., scores in the top 2 categories of the Zwisch scale) by postgraduate year (PGY), and "progressive autonomy" (i.e., differences in autonomy between PGYs) in MIS procedures, as rated by attending surgeons. Primary outcomes were determined with descriptive statistics, one-way analysis of variance (ANOVA) and Z-tests. Secondary analyses compared (i) progressive autonomy between common MIS procedures, and (ii) progressive autonomy in MIS vs. non-MIS procedures. RESULTS: A total of 106,054 evaluations were performed across 50 General Surgery residency programs, of which 38,985 (37%) were for MIS procedures. Attendings performed 44,842 (42%) of all evaluations, including 16,840 (43%) of MIS evaluations, while residents performed the rest. Overall, meaningful autonomy in MIS procedures increased from 14.1% (PGY1s) to 75.9% (PGY5s), with significant (p < 0.001) increases between each PGY level. Meaningful autonomy rates were higher in the MIS vs. non-MIS group [57.2% vs. 48.0%, p < 0.001], and progressed more rapidly in MIS vs. non-MIS, (p < 0.05). The 7 most common MIS procedures accounted for 83.5% (n = 14,058) of all MIS evaluations. Among PGY5s performing these procedures, meaningful autonomy rates (%) were: laparoscopic appendectomy (95%); laparoscopic cholecystectomy (93%); diagnostic laparoscopy (87%); upper/lower endoscopy (85%); laparoscopic hernia repair (72%); laparoscopic partial colectomy (58%); and laparoscopic sleeve gastrectomy (45%). CONCLUSIONS: US General Surgery residents receive progressive autonomy in MIS procedures, and appear to progress more rapidly in MIS versus non-MIS procedures. However, residents fail to achieve meaningful autonomy in nearly 25% of MIS cases in their final year of residency, with higher rates of meaningful autonomy only achieved in a small subset of basic MIS procedures.

Mind the Gap: The Autonomy Perception Gap in the Operating Room by Surgical Residents and Faculty.

OBJECTIVE: Examine the concordance of perceived operative autonomy between attendings and resident trainees. DESIGN: Faculty and trainees rated trainee operative autonomy using the 4-level Zwisch scale over a variety of cases and training years. The respective ratings were then compared to explore the effects of experience, gender, case complexity, trainee, trainer, and other covariates to perceived autonomy. SETTING: This study was conducted over 14 general surgery programs in the United States, members of the Procedural Learning and Safety Collaborative. PARTICIPANTS: Participants included faculty and categorical trainees from 14 general surgery programs. RESULTS: A total of 8681 observations was obtained. The sample included 619 unique residents and 457 different attendings. A total of 598 distinct procedures was performed. In 60% of the cases, the autonomy ratings between trainees and attendings were concordant, with only 3.5% of cases discrepant by more than 1 level. An autonomy perception gap was modeled based on the discrepancy between the trainee and attending Zwisch ratings for the same case. The mean Zwisch score expected for a trainee was lower than the attending across all scenarios. Trainees were more likely to perceive relatively more autonomy in the second half of the year. The autonomy perception gap decreased with increasing case complexity. As trainees gained experience, the perception gap increased with trainees underestimating autonomy. CONCLUSIONS: Trainees and attendings generally demonstrated concordance on autonomy perception scores. However, in 40% of cases, a perception gap exists between trainee and attending with the trainee generally underestimating autonomy. The gap worsens as the trainee progresses through residency. This perception gap suggests that attendings and trainees could be better aligned on teaching goals and expectations.

Concordance Between Expert and Nonexpert Ratings of Condensed Video-Based Trainee Operative Performance Assessment.

OBJECTIVE: We examined the impact of video editing and rater expertise in surgical resident evaluation on operative performance ratings of surgical trainees. DESIGN: Randomized independent review of intraoperative video. SETTING: Operative video was captured at a single, tertiary hospital in Boston, MA. PARTICIPANTS: Six common general surgery procedures were video recorded of 6 attending-trainee dyads. Full-length and condensed versions (n = 12 videos) were then reviewed by 13 independent surgeon raters (5 evaluation experts, 8 nonexperts) using a crossed design. Trainee performance was rated using the Operative Performance Rating Scale, System for Improving and Measuring Procedural Learning (SIMPL) Performance scale, the Zwisch scale, and ten Cate scale. These ratings were then standardized before being compared using Bayesian mixed models with raters and videos treated as random effects. RESULTS: Editing had no effect on the Operative Performance Rating Scale Overall Performance (-0.10, p = 0.30), SIMPL Performance (0.13, p = 0.71), Zwisch (-0.12, p = 0.27), and ten Cate scale (-0.13, p = 0.29). Additionally, rater expertise (evaluation expert vs. nonexpert) had no effect on the same scales (-0.16 (p = 0.32), 0.18 (p = 0.74), 0.25 (p = 0.81), and 0.25 (p = 0.17). CONCLUSIONS: There is little difference in operative performance assessment scores when raters use condensed videos or when raters who are not experts in surgical resident evaluation are used. Future validation studies of operative performance assessment scales may be facilitated by using nonexpert surgeon raters viewing videos condensed using a standardized protocol.

A Total Offloading Foot Brace for Treatment of Diabetic Foot Ulcers: Results From a Halted Randomized Controlled Trial.

INTRODUCTION: Foot offloading is the mainstay treatment for plantar diabetic foot ulcers (DFUs). OBJECTIVE: This multicenter, single-blinded, randomized controlled trial evaluates the efficacy of a total offloading foot brace for healing plantar DFUs. MATERIALS AND METHODS: Seventeen patients were randomized to standard therapy (ie, reducing stress and pressure via mechanical offloading) or offloading foot brace. Comparison of plantar pressures was performed using digital pressure sensing films. The ulcers were assessed by physical inspection and digital planimetry of photographs. RESULTS: Reductions in peak plantar pressures ranged from 67.3% to 89.4% (P = .09). Healing at weeks 12 to 15 had minimal differences (brace vs. control: 71.7% vs. 80.3%, respectively). Although not significant, earlier periods of the brace versus the control demonstrated faster wound healing in weeks 2 to 5 (36.0% vs. 6.8%, respectively) and weeks 6 to 9 (50.7% vs. 17.0%, respectively). CONCLUSIONS: The total offloading foot brace minimizes plantar pressure, allowing for early healing of DFUs, and optimizations in brace design may enhance healing of plantar DFUs.

Characterizing tissue perfusion after lower extremity intervention using two-dimensional color-coded digital subtraction angiography.

OBJECTIVE: Digital subtraction angiography (DSA) of the peripheral arterial vasculature provides lumenographic information but only a qualitative assessment of blood flow. The ability to quantify adequate tissue perfusion of the lower extremities would enable real-time perfusion assessment during DSA of patients with peripheral arterial disease (PAD). In this study, we used a novel real-time imaging software to delineate tissue perfusion parameters in the foot in PAD patients. METHODS: Between March 2015 and June 2016, patients (N = 31) underwent lower extremity angiography using a two-dimensional perfusion (2DP) imaging protocol (Philips Healthcare, Andover, Mass). Of the 31 enrolled patients, 16 patients received preintervention and postintervention DSA images (18 angiograms), while contrast agent injection settings and the position of the foot, catheter, and C-arm were kept constant. The region of interest for perfusion measurements was taken at the level of the medial malleolus. Perfusion parameters included arrival time (AT) of contrast material, wash-in rate (WIR), time to peak (TTP) contrast intensity, and area under the curve (AUC). RESULTS: Patients (mean age, 67 years; male, 61%) undergoing 2DP had limbs classified as Rutherford class 3 (n = 9 limbs), class 4 (n = 11), and class 5 (n = 14) ischemia with a mean ankle-brachial index of 0.63. For the whole cohort, median (interquartile range) AT measured 5.20 (3.10-7.25) seconds; WIR, 61.95 (43.53-86.43) signal intensity (SI)/s; TTP, 3.80 (2.88-4.50) seconds; peak intensity, 725.00 (613.75-1138.00) SI; and AUC, 12,084.00 (6742.80-17,059.70) SI*s. A subset of patients had 2DP performed before and after intervention (n = 18 cases). A detectable improvement in SI and two-dimensional flow parameters was seen after intervention. Average AT of contrast material to the region of interest shortened after intervention with percentage decrease of 30.1% ± 49.1%, corresponding decrease in TTP of 17.6% ± 24.7%, increase in WIR of 68.8% ± 94.2% and in AUC of 10.5% ± 37.6%, decrease in mean transit time of 18.7% ± 28.1%, and increase in peak of 34.4% ± 42.2%. CONCLUSIONS: The 2DP imaging allows measurement of blood flow in real time as an adjunct to DSA. The AT may be the most sensitive marker of perfusion change in the lower extremity. Quantitative thresholds based on 2DP hold promise for immediate treatment effectiveness assessment in patients with PAD.

Simulation of carotid artery stenting reduces training procedure and fluoroscopy times.

OBJECTIVE: Outcomes from carotid artery stenting (CAS) are related to experience and technical expertise of the operator. Simulation of CAS may enhance clinical proficiency. We interrogated the impact of endovascular simulation of CAS procedures in operators who are at various stages of training. METHODS: Twelve trainees (students [n = 4]; junior surgery residents, postgraduate year [PGY] 1-3 [n = 4]; and senior surgery residents or fellows, PGY 4-7 [n = 4]) were apprised of characteristics of an endovascular simulator and CAS procedures. This was followed by four independent sessions that were assessed for objective measures including procedure and fluoroscopy times and contrast agent use. A qualitative analysis grading steps of CAS by two observers using a Likert scale was performed. One-way analysis of variance and paired t-tests were employed for data analysis. RESULTS: For all participants (n = 12), procedure times (mean, 920 ± 279 seconds for the first session vs 454 ± 156 seconds for the fourth session; P < .01; confidence interval [CI], 315-621) and fluoroscopy cumulative times (mean, 421 ± 230 seconds for the first session vs 222 ± 102 seconds for the fourth session; P < .01; CI, 78-285) decreased with progression of cases. Students and PGY 1-3 residents decreased their procedure times significantly in comparison of initial and final sessions (P < .05 and P < .01, respectively). For all groups, fluoroscopy cumulative times were reduced, and this decrement was significant in the PGY 1-3 cohort (mean, 444 ± 8 seconds for the first session vs 265 ± 51 seconds for the fourth session; P < .01; CI, 81-276). Initial CAS procedure times were significantly different between groups (P < .05), but this was observed to resolve by the final case at study completion. Qualitatively, the Likert scores of students and PGY 1-3 residents significantly improved with case repetition, specifically in the following steps: (1) cannulation of common carotid artery and (2) sizing and deployment of embolic protection device. Senior operators (PGY 4-7) demonstrated consistently better performance overall with minimal change in scoring with case repetition. CONCLUSIONS: Practice leads to improvements in endovascular simulator procedure and fluoroscopy times, especially for more novice trainees. Initial operator performance gaps can be approximated with a few sessions to expected proficiency. Incorporation of endovascular simulators in residency training may assist in shortening the learning curve in rarer endovascular procedures.

Endothelial Function Is Preserved in Veins Harvested by Either Endoscopic or Surgical Techniques.

BACKGROUND: Endoscopic vein harvest for lower extremity arterial bypass grafting has been questioned due to concern for endothelial damage during procurement. We sought to compare nitric oxide (NO)-mediated endothelial-dependent relaxation (EDR) in vein segments harvested using open surgical techniques (OH) versus endoscopic vein harvest (EH) techniques. METHODS: Saphenous vein segments were harvested for lower extremity bypass, and a single, minimally handled section of saphenous vein, free of branches, was taken from the end of the graft. Four 4-mm venous ring segments were then cut and mounted on force transducers. Segments were mounted in 37° oxygenated Krebs-Henseleit solution and maximally contracted using KCl. Individual ring segments that did not react to KCl were excluded from the study. Norepinephrine (NE) was used to achieve submaximal contraction. EDR was determined using increasing concentrations of bradykinin (BDK). Endothelial-independent relaxation (EIR) was confirmed using sodium nitroprusside. Two-way analysis of variance (ANOVA) was used to analyze differences between harvest techniques across BDK concentration and a Student's t-test was used to analyze single comparisons. RESULTS: Vein segments harvested from patients (n = 13) led to 28 viable rings that exhibited a positive reaction to KCl (11 rings; 5 patients EH vs. 17 rings; 8 patients OH). Both vein groups achieved moderate relaxation to maximal BDK concentration, [10-6 M]; (49.5% EH vs. 40.55% OH, P = 0.270). Analysis by 2-way ANOVA for mean % relaxation for BDK concentration [10-11-10-6 M] showed improved EDR in EH samples compared with OH (P = 0.029). Mean nitrite/nitrate (NO(x)) tissue bath concentration measurements post-BDK were 139.8 nM (EH) vs. 97.2 nM (OH; P = 0.264). Histology and positive factor VIII immunohistochemistry staining provided evidence for the presence of intact endothelium in our sample segments. EIR was preserved and was similar in the two groups. CONCLUSIONS: Endothelial function is preserved when utilizing endoscopic harvesting techniques. The advantages of minimally invasive vein procurement for lower extremity bypass can be obtained without concern for damaging venous endothelium.