Early Learning Period Research Articles

Learning curve for imageless robotic-assisted total knee arthroplasty in non-fellowship trained joint replacement surgeons

IntroductionRobotic-assisted total knee arthroplasty (RA-TKA) has become increasingly popular, although an associated learning curve can be a deterrent for some surgeons. Prior studies have addressed this learning curve in fellowship-trained arthroplasty surgeons, however the learning curve among non-fellowship-trained surgeons remains unclear. The objective of this study was to investigate the learning curve for imageless RA-TKA related to operative time and rates of complications among two non-arthroplasty-trained orthopedic surgeons. MethodsThis retrospective case series included 200 RA-TKA consecutive cases performed by two non-arthroplasty-trained orthopedic surgeons (100 each). Cases were divided into 2 cohorts for each surgeon: the first 50 consecutive cases and the second 50 cases. These cohorts were then compared to assess for trends in each surgeon as well as in both surgeons combined. Mean operative times were compared, as were hospital length of stay, complications, readmission, and reoperations. ResultsFor both surgeons, the mean operative time significantly decreased from the first 50 cases to the next 50 cases (116.5 vs 108.4 min for surgeon 1, P = 0.031; 125.7 vs 109.1 min for surgeon 2, P = 0.001). No significant differences were found among length of stay, complications, readmissions, or reoperations between cohorts. ConclusionGeneral orthopedic surgeons can expect to optimize operative time within 50 cases, while not carrying associated risks of related complications during the early learning period.

Generalization of procedural motor sequence learning after a single practice trial

When humans begin learning new motor skills, they typically display early rapid performance improvements. It is not well understood how knowledge acquired during this early skill learning period generalizes to new, related skills. Here, we addressed this question by investigating factors influencing generalization of early learning from a skill A to a different, but related skill B. Early skill generalization was tested over four experiments (N = 2095). Subjects successively learned two related motor sequence skills (skills A and B) over different practice schedules. Skill A and B sequences shared ordinal (i.e., matching keypress locations), transitional (i.e., ordered keypress pairs), parsing rule (i.e., distinct sequence events like repeated keypresses that can be used as a breakpoint for segmenting the sequence into smaller units) structures, or possessed no structure similarities. Results showed generalization for shared parsing rule structure between skills A and B after only a single 10-second practice trial of skill A. Manipulating the initial practice exposure to skill A (1 to 12 trials) and inter-practice rest interval (0–30 s) between skills A and B had no impact on parsing rule structure generalization. Furthermore, this generalization was not explained by stronger sensorimotor mapping between individual keypress actions and their symbolic representations. In contrast, learning from skill A did not generalize to skill B during early learning when the sequences shared only ordinal or transitional structure features. These results document sequence structure that can be very rapidly generalized during initial learning to facilitate generalization of skill.

Learning curve for biportal endoscopic posterior cervical foraminotomy determined using the cumulative summation test

BackgroundLearning curves describe the rate of performance improvements corresponding to the surgeon’s caseload, followed by a plateau where limited further improvements are observed. This study aimed to determine the learning curve for biportal full-endoscopic posterior cervical foraminotomy (BE-PCF) for the unilateral cervical foraminal disc.MethodsThe learning curve was evaluated using a learning curve cumulative summation test (LC-CUSUM). The goal for the operation time was set to 78 min, which is the mean operation time (mOT) of percutaneous full-endoscopic posterior cervical foraminotomy (PE-PCF) performed by a senior surgeon. Moreover, clinical outcomes and post-operative complications were compared between the early and late learning periods 1 year post-operatively.ResultsThis study enrolled the first 50 patients who underwent single-level BE-PCF, performed by a single surgeon. The LC-CUSUM signalled competency for surgery at the 20th operation, indicating that sufficient evidence was obtained to prove that the surgeon was competent. The mOT was 71.29 ± 11.69 min in BE-PCF, 71.84 ± 12.61 min in the early learning period, and 67.83 ± 10.31 min in the late learning period (p = 0.254). There was no statistical difference in clinical outcomes, visual analogue scale scores, and neck disability index between both periods (p > 0.05). Four complications were recorded throughout the whole period, with three in the early period and one in the late period (p = 0.285).ConclusionOur study shows that BE-PCF has a learning curve of 20 caseloads to achieve 90% proficiency, and it significantly reduces the operation time based on the performance of a senior surgeon proficient in PE-PCF.

The First Step in Inculcating Reading: Insights from UAE on Efficacy in Teaching Kindergarteners to Read in the Arabic Language

The purpose of this study was to investigate how the knowledge and self-efficacy of kindergarten school teachers impact students’ learning outcomes namely Arabic language reading skills. The study was a cross-sectional survey and collected data from 120 kindergarten teachers. The study showed that there is a significant positive relationship between knowledge and self-efficacy, both contributing to better learners’ experience during early learning periods. The null hypothesis of the study was that there was a difference in the teacher’s gender in their ability to create enthusiasm in class. The teacher’s gender difference had an insignificant effect. The study also found that there is still a challenge to effectively teach children with reading difficulties like dyslexia.

Learning curve for microscopic unilateral laminectomy for bilateral decompression surgery using the cumulative summation test for learning curve.

A retrospective observational study The purpose of this study was to characterize the learning curve for a single level unilateral laminectomy and bilateral decompression in lumbar spinal stenosis using a learning curve cumulative summation test. Unilateral laminectomy and bilateral decompression for lumbar spinal stenosis proposes a potential benefit with minimizing surgery-related instability compared to traditional bilateral laminectomy, by preserving posterior stabilizing structures and contralateral facet joint and neural arch. Due to a narrow surgical corridor, it is considered to exhibit a steep learning curve as other types of minimally invasive procedures. However, there are few reports available regarding learning curve of unilateral laminectomy and bilateral decompression. The learning curve of a single surgeon performing single level unilateral laminectomy and bilateral decompression was assessed using learning curve cumulative summation test analysis. The surgeon had minimal experience in open decompressive laminectomy but no previous experience in unilateral laminectomy and bilateral decompression. Procedure success was defined as an operation time less than 75 minutes. Surgery related complications were recorded. Total 194 consecutive patients, who underwent primary single level unilateral laminectomy and bilateral decompression by a single spine surgeon, were included. The mean operative time for unilateral laminectomy and bilateral decompression was 64.6 ± 23.6 minutes. The mean operative time in the early learning period (≤29th case) was 80.6 ± 20.9 minutes, and that in the late learning period (after 29th case) was 61.8 ± 22.7 minutes, respectively. The overall complication rate was 13.9%. Majority of complications occurred in the early learning period. The learning curve cumulative summation test signaled competency for unilateral laminectomy and bilateral decompression at the 29th operation, indicating that the surgeon reached the competent level. In addition, based on the cumulative summation test, the surgeon seemed to maintain his competency for the procedure. This study showed that surgical experience reduced the operation time and surgery related complications. For inexperienced surgeon to achieve an acceptable outcome in unilateral laminectomy and bilateral decompression, minimum 30 cases of unilateral laminectomy and bilateral decompression are required to reach competent level of surgery.

Sound sensitivity in dogs: protecting emotional welfare and the human–pet bond

The dog's auditory system is designed in such a way that it will be aware of sounds that are sudden or presented in an unusual manner, and it is reasonable to suggest that sound sensitivity is adaptive in dogs. Studies of sound sensitivity in dogs have mainly focused on intense but occasional sounds, such as fireworks, thunder and gunshots; these studies suggest that almost half of the domestic canine population suffer a depletion in emotional welfare when exposed to such sounds. A dog's early learning period is largely intended to ensure that it learns to ignore stimuli that are inconsequential to its safety. However, both the environment within and outside human homes can be intensely noisy and unpredictable, regularly exposing many dogs to inescapable sounds that they did not meet during their early developmental period, which can initiate emotional responses of anxiety, fear and frustration and a motivation for avoiding sound-producing stimuli. This article discusses the issue of sound sensitivity in dogs, and considers the extent to which sensitivity to everyday soundscapes will become an increasing emotional health problem in the domestic canine population.

Talking to Children About Racial Bias

Given the tragic and racially-charged current events, many parents are wrestling with their own feelings, the hopes they have for their children, and the difficulty of helping those children thrive in a world full of racial bias.Parents may better face today's challenges with an understanding of how racial bias works in children, as well as strategies to help them deal with and react to racial differences.Children learn about racial differences and racial bias from an early age and learn from their first teachers—their parents—how to deal with and react to these differences.The process of learning racial bias is a lot like learning a new language (e.g., a child raised bilingual vs. a child who starts learning Spanish in junior high). Biology determines a critical early learning period as well as a later window where learning is much harder.But like language immersion, children exposed to society will gain fluency in racial bias even if their parents do nothing.There are three strategies that parents can use to help their children deal with racial bias:Parents must first confront their own biases, so that their example is consistent with messages of racial and ethnic tolerance.Talking about race is not racist. It's OK—and important. From a young age, children may have questions about racial differences and parents must be prepared to answer them. But, it's important to keep your child's developmental readiness in mind.These conversations begin to lay the groundwork for your child to accept and respect everyone's differences and similarities. As children mature, the answers to questions will become more complex. These are moments to learn what your child understands or is struggling to understand about racial bias.To create a culture of inclusiveness, we all must look at and acknowledge our biases, so we can do something about the ones that are unfair or cause harm to others—like racial bias. Understanding the way people feel about and behave toward those outside their own group can help communities heal after a tragedy, as well as prevent future ones.Adapted from the HealthyChildren.org article Talking to Your Children About Racial Bias by Ashaunta Anderson, MD, MPH, MSHS, FAAP, and Jacqueline Dougé, MD, MPH, FAAP (6/25/20).The American Academy of Pediatrics (AAP) is an organization of 67,000 primary care pediatricians, pediatric medical subspecialists, and pediatric surgical specialists dedicated to the health, safety, and well-being of all infants, children, adolescents, and young adults.In all aspects of its publishing program (writing, review, and production), the AAP is committed to promoting principles of equity, diversity, and inclusion.The information contained in this publication should not be used as a substitute for the medical care and advice of your pediatrician. There may be variations in treatment that your pediatrician may recommend based on individual facts and circumstances.

Default mode and dorsal attention network involvement in visually guided motor sequence learning

Motor sequence learning (MSL) paradigms are often used to investigate the neural processes underlying the acquisition of complex motor skills. Behavioral and neuroimaging studies have indicated an early stage in which spatial learning is prominent and a late stage of automatized performance after multiple training periods. Functional magnetic resonance imaging (fMRI) studies yielded both decreased and increased activations of the sensorimotor and association areas. However, task-negative and task-positive intrinsic connectivity networks (ICNs), the default mode (DMN) and dorsal attention (DAN) networks involved in governing attention demands during various task conditions were not specifically addressed in most studies. In the present fMRI study, a visually guided MSL (VMSL) task was used for bringing roles of visuospatial and motor attention into foreground in order to investigate the role of attention-related ICNs in MSL. Seventeen healthy, right-handed participants completed training and test sessions of VMSL during fMRI on the 1st day. Then, after daily training for three consecutive days outside the scanner, they were re-tested during the 5th day's scanning session. When test session after early learning period was compared with training session, activation decrease was observed in the occipito-temporal fusiform cortex, while task-related suppression of DMN was reduced. Reduced deactivation after early learning was correlated with decreased error rates. After late learning stage we observed activation decreases in bilateral superior parietal lobules of task-positive DAN, dorsal precunei, and cerebellum. Reduced activity in left posterior parietal and right cerebellar regions were correlated with gains in speed, error rate, respectively. This dissociation in activity changes of DMN and DAN related areas suggests that DAN shows high contribution during both early and late MSL stages, possibly due to attention requirement for automatization of spatial and temporal aspects of motor sequence. In contrast, spatial learning occurring during early MSL stage was sufficient for releasing DMN resources.

The outcome of laparoscopic pancreatoduodenectomy is improved with patient selection and the learning curve.

In our first experience, laparoscopic pancreatoduodenectomy (LPD) was associated with higher morbidity than open PD. Since, the surgical technique has been improved and LPD was avoided in some patients at very high risk of postoperative pancreatic fistula (POPF). We provide our most recent results. Between 2011 and 2018, 130 LPD were performed and divided into 3 consecutive periods based on CUSUM analysis and compared: first period (n = 43), second period (n = 43), and third period (n = 44). In the third period of this study, LPD was more frequently performed in women (46%, 39%, 59%, p = 0.21) on dilated Wirsung duct > 3mm (40%, 44%, 57%; p = 0.54). Intraductal papillary mucinous neoplasm(IPMN) became the primary indication (12%, 39%, 34%; p = 0.037) compared to pancreatic adenocarcinoma (35%, 16%, 16%; p = 0.004). Malignant ampulloma re-increased during the third period (30%, 9%, 20%; p = 0.052) with the amelioration of surgical technique. The operative time increased during the second period and decreased during the third period (330, 345, 270; p < 0.001) with less blood loss (300, 200, 125; p < 0.001). All complications decreased, including POPF grades B/C (44%, 28%, 20%; p = 0.017), bleeding (28%, 21%, 14%; p = 0.26), Clavien-Dindo III-IV (40%, 33%, 16%; p = 0.013), re-interventions (19%, 14%, 9%; p = 0.43), and the hospital stay (26, 19, 18; p = 0.045). Less patients with similar-sized adenocarcinoma were operated during the second period (70%, 33%, 59%; p = 0.002) with more harvested lymph nodesin the third period(21,19, 25; p = 0.031) and higher R0 resection (70%, 79%, 84%; p = 0.5). On multivariate analysis the protective factors against POPF of grades B/C were pancreatic adenocarcinoma and invasive IPMN, BMI < 22.5kg/m2, and patients operated in the third period. This study showed that the outcome of LPD significantly improves with the learning curve and patient selection. For safe implementation and during the early learning period, LPD should be indicated in patients at lower risk of POPF.

Risk Factors and Options of Management for an Incidental Dural Tear in Biportal Endoscopic Spine Surgery.

Study DesignHere we perform a retrospective analysis regarding an incidental dural tear (IDT) during biportal endoscopic spinal surgery (BESS).PurposeThis study investigates the causes of IDT specifically related to technical procedures of BESS with the aim of lowering its risk during training.Overview of LiteratureThe incidence of dural tear is reported 0.5%–18% in open spinal surgery and 1.7%–4.3% during endoscopic spinal surgery. Because conversion to open surgery for direct repair could become necessary during endoscopic spinal surgery, prevention of this complication is essential.MethodsWe have retrospectively studied IDTs by four surgeons during 1 or 2 years after starting BESS for lumbar degenerative diseases and analyzed the locations, sizes, and specific endoscopic conditions specific to each.ResultsTwenty-five cases (1.6%) of IDTs among 1,551 cases of BESS occurred; 13 cases (52%) of these were within the first 6 months. The locations were dorsal midline in 12 cases, ipsilateral side in 11 cases, and contralateral side in two cases. The tear sizes were <10 mm in 20 cases and ≥10 mm in five cases. IDT commonly occurred due to injury of central dural folding during flavectomy under turbid surgical fields due to small bleeds under water. Twenty cases with IDTs of <10 mm were treated well with the patch technique. Among five cases of ≥10 mm, three underwent open repair within a few days, and two of these which failed to conservative management required a delayed revision operation due to pseudomeningocele. No cases progressed to surgical site infection or infectious spondylitis.ConclusionsIDTs of <10 mm can be successfully treated with the patch technique. To prevent IDT during the early learning period, maintaining clear visibility by securing fluent saline outflow and meticulous hemostasis of small bleeding from exposed cancellous bone and epidural vessels is essential with caution not to injure the central dural folding during midline flavectomy.

Learning Curve and Initial Experience With Implementation of a His-Bundle Pacing Program in an Australian Setting

His-bundle pacing (HBP) has emerged as a promising technique to avoid pacing complications associated with dyssynchrony from right ventricular pacing, but data are limited to experienced operators and centres. We aimed to evaluate the implementation and outcomes of an HBP program in an Australian setting. Data were retrospectively collected on 140 consecutive HBP procedures attempted at three centres from March 2018 to September 2019. The cohort was divided into three groups (early: procedures 1-47, middle: 48-94, late: 95-140) to determine changes in procedural success in relation to operator experience. Median age was 76 years (IQR 68-80 yrs); 69% were male. Atrial fibrillation was present in 59%, left ventricular ejection fraction (LVEF) ≤40% in 25%, and left and right bundle branch blocks present in 23% and 16% respectively, and atrioventricular (AV) block was present in 26%. Overall procedural success was 87%, median implant threshold 0.8V@1 ms, and QRS duration improved in 64% of procedures. Procedural success (early 83%, middle 89%, late 89%, p=0.58) was not different, while median procedural time (early 98 mins, middle 83 mins, late 70 mins, p<0.001) improved across operator experience groups. Lower success rates were identified for patients with AV block (73% vs. 92%, p<0.01), a previous device (69% vs. 89%, p=0.02), moderate-severe TR (69% vs. 88%, p=0.04), and when right-sided access was required (25% vs. 89%, p<0.01). His-bundle pacing is a feasible procedure with continued improvement in procedural measures of success after an early learning period. The presence of AV block, a previous device, significant tricuspid regurgitation, or right-sided access may affect procedural success.

Learning Curve for Percutaneous Endoscopic Lumbar Diskectomy in Bi-needle Technique Using Cumulative Summation Test for Learning Curve

The purpose of this study was to determine the number of cases needed to achieve the level of competence for percutaneous endoscopic lumbar diskectomy (PELD) via the bi-needle technique using the cumulative summation test for learning curve (LC-CUSUM). A retrospective design was used. We included 60 patients who underwent a single-level PELD via the bi-needle technique performed by a single surgeon. The surgeon had 5 years of experience in open surgery including the transforaminal endoscopic spine system and Yeung endoscopic spine system but no experience in the bi-needle technique. Surgery success was defined as an operative time <60 minutes, and the acceptable procedure was completed within 3 times of C-arm fluoroscopies. The LC-CUSUM was used to analyze the data. The average operative time for PELD via the bi-needle technique was 58.3 ± 12.4 minutes. The mean operative time was 65.7 ± 12.1 minutes in the early learning period (30 cases) and 51.0 ± 7.5 minutes in the late learning period (30 cases) (P < 0.05). On the basis of the evaluation indexes of the operative time and radioactive exposure, the LC-CUSUM signaled proficiency for the bi-needle technique at the 50th-54th operation. Seven cases of complications were observed during the whole learning process, with 6 in the early period and 1 in the late period (P < 0.05). The novel bi-needle technique is safe and effective for PELD with appropriate patients, and the learning curve is acceptable. A substantial learning period (50-54 cases) is needed before a spine surgeon can master the bi-needle technique.

Learning Curve for Lumbar Decompressive Laminectomy in Biportal Endoscopic Spinal Surgery Using the Cumulative Summation Test for Learning Curve

The purpose of the present study was to determine the learning curve for biportal endoscopic spinal surgery (BESS) for decompressive laminectomy in lumbar spinal stenosis using a learning curve cumulative summation test (LC-CUSUM). The surgeon was proficient in open and microscopic decompressive laminectomy in lumbar spinal stenosis but did not have any experience with BESS or other endoscopic surgery techniques. The learning curve of BESS was investigated using LC-CUSUM analysis. Procedure success was defined as an operative time <75 minutes, the mean operative time with microscopic decompression laminectomy. The present study included the first 60 patients who had undergone single-level decompressive laminectomy using BESS by a single orthopedic surgeon. The mean operative time for decompressive laminectomy by BESS was 83.8 ± 37.9 minutes. The mean operative time in the early learning period (≤30 cases) and late learning period (second 30 cases) was 105.3 ± 39.7 minutes and 62.4 ± 19.9 minutes, respectively. The overall complication rate was ∼10%. The LC-CUSUM signaled competency for surgery at the 58th operation, indicating that sufficient evidence had accumulated to prove that the surgeon was competent. Thus, a trainee with no experience with BESS had reached adequate performance at 58 cases. The results of the present study have demonstrated that a substantial learning period could be needed before adequate performance can be achieved with lumbar decompressive laminectomy using BESS.

P6387A comparison of procedural and short-term clinical outcomes of left atrial appendage occlusion between amplatzer cardiac plug and watchman device in the early learning periods

P6387A comparison of procedural and short-term clinical outcomes of left atrial appendage occlusion between amplatzer cardiac plug and watchman device in the early learning periods

Predictive Coding for Dynamic Visual Processing: Development of Functional Hierarchy in a Multiple Spatiotemporal Scales RNN Model.

This letter proposes a novel predictive coding type neural network model, the predictive multiple spatiotemporal scales recurrent neural network (P-MSTRNN). The P-MSTRNN learns to predict visually perceived human whole-body cyclic movement patterns by exploiting multiscale spatiotemporal constraints imposed on network dynamics by using differently sized receptive fields as well as different time constant values for each layer. After learning, the network can imitate target movement patterns by inferring or recognizing corresponding intentions by means of the regression of prediction error. Results show that the network can develop a functional hierarchy by developing a different type of dynamic structure at each layer. The letter examines how model performance during pattern generation, as well as predictive imitation, varies depending on the stage of learning. The number of limit cycle attractors corresponding to target movement patterns increases as learning proceeds. Transient dynamics developing early in the learning process successfully perform pattern generation and predictive imitation tasks. The letter concludes that exploitation of transient dynamics facilitates successful task performance during early learning periods.

Changes in prostate cancer detection rate of MRI-TRUS fusion vs systematic biopsy over time: evidence of a learning curve.

To determine the effect of urologist and radiologist learning curves and changes in MRI-TRUS fusion platform during 9 years of NCI's experience with multiparametric magnetic resonance imaging (mpMRI)/TRUS fusion biopsy. A prospectively maintained database of patients undergoing mpMRI followed by fusion biopsy (Fbx) and systematic biopsy (Sbx) from 2007 to 2016 was reviewed. The patients were stratified based on the timing of first biopsy. Cohort 1 (7/2007-12/2010) accounted for learning curve. Cohort 2 (1/2011-5/2013) and cohort 3 (5/2013-4/2016) included patients biopsied prior to and after debut of a new software platform, respectively. Clinically significant (CS) disease was defined as Gleason 7 (3+4) or higher. McNemar's test compared cancer detection rates (CDRs) of Sbx and Fbx between time periods. 1528 patients were included in the study with 230, 537 and 761 patients included in three respective cohorts. Median age (interquartile range) was 61.0 (±9.0), 62.0 (±7.3), and 64.0 (±11.0) years in three cohorts, respectively (P<0.001). Fbx and Sbx had comparable CS CDR in cohort 1 (24.8 vs 22.2%, P=0.377). Fbx detected significantly more CS disease compared to Sbx in the following two periods (cohort 2: 31.5 vs 25.0%, P=0.001; cohort 3: 36.4 vs 30.3%, P<0.001) and detected significantly less low risk disease in the same period (cohort 2: 14.5 vs 19.6%, P<0.001; cohort 3: 12.6 vs 16.7%, P<0.001). Even after multivariate adjustment with age, PSA, race, clinical stage and MRI suspicion score, Fbx CS cancer detection increased in successive cohorts (cohort 2: OR 2.23, P=0.043; cohort 3: OR 2.92, P=0.007). In the past 9 years, there has been significant improvement in the accuracy of Fbx. Our results show that after an early learning period, Fbx detected higher rates of CS cancer and lower rates of clinically insignificant cancer than Sbx. Software advances allowed for even greater detection of CS disease.

Changes in prostate cancer detection rate of fusion versus systematic biopsy over time: A single center experience.

15 Background: To determine the effect of learning curves and changes in fusion platform during 9 years of NCI’s experience with multiparametric MRI (mpMRI)/TRUS fusion biopsy. Methods: A review was performed of a prospectively maintained database of patients undergoing mpMRI followed by fusion biopsy (Fbx) and systematic biopsy (Sbx) from 2007−2016. The patients were stratified based on the timing of first biopsy in 3 groups. Cohort 1 included patients biopsied between 7/2007−12/2010, accounting for learning curve at our institution. Cohort 2 included patients biopsied from 1/2011 up to the debut of UroNav (Invivo) platform in 5/2013. Cohort 3 included patients biopsied after 5/2013. Clinically significant (CS) disease was defined as Gleason 7 (3+4) or higher. Cancer detection rates (CDR) between Sbx and Fbx during different time periods were compared using McNemar’s test. Age and PSA standardized CDRs were calculated for comparison between 3 cohorts. Results: 1528 patients were included in the study with 219, 549 and 761 patients included in 3 respective cohorts. Mean age, PSA and race distribution were similar across 3 cohorts. In cohort 1 there was no significant difference between CDR of CS disease by Fbx (24.7%) vs Sbx (21.5%), p = 0.377. Fbx was significantly better than Sbx in detection of CS disease in cohort 2 and cohort 3 (31.5% vs 25.3%, p = 0.001; 36.5% vs 30.2%, p &lt; 0.001, respectively). There was significant decline in detection of low risk disease by Fbx compared to Sbx in the same period (cohort 2: 14.2% vs 20.9%, p &lt; 0.001; cohort 3: 12.5% vs 19.5%, p &lt; 0.001). Age and PSA standardized CDR of CS cancer by Fbx increased significantly between each successive cohort (cohort 1 and 2: 5.2%, 95% CI [2.1-8.5]), 2 and 3 (5.2%, 95% CI [1.8-8.6]). Conclusions: Our results show that after an early learning period using Fbx, CS prostate cancer was detected at significantly higher rates with Fbx than with Sbx, and low risk disease was detected at lower rates. Advances in software allowed for even greater detection of CS disease in the last cohort. This study shows that accuracy of Fbx is dependent on multiple factors; surgeon/radiologist experience and software improvements together produce improved accuracy.

Abstract P1-11-06: Learning curve for the SAVI SCOUT breast localization and surgical guidance system

Abstract Background: The gold standard for localizing non-palpable breast lesions for surgical excision is wire localization (WL). Multiple disadvantages for WL include complicated scheduling and migration of the wire after placement. Radioactive seed localization (RSL) mitigates these disadvantages, but regulatory requirements regarding radiation limit more universal adoption. The SAVI SCOUT surgical guidance system (an FDA cleared medical device) eliminates the drawbacks of WL without the regulatory requirements of RSL. SCOUT utilizes electromagnetic wave technology and infrared light to provide intra-operative guidance during surgical excision. The purpose of this study is to describe the learning curve associated with adoption of this new technology. Method: An IRB-approved prospective, single-arm, multi-site trial enrolled women with non-palpable breast lesions requiring localized surgical excision. After informed consent, a radiologist or surgeon used imaging guidance to implant the SCOUT reflector into the target lesion. Intraoperatively, the surgeon used SCOUT for localization of the reflector and removal of the target lesion. We evaluated the association of several independent variables with respect to successful localization and surgical excision including: tumor side, tumor quadrant, distance of reflector from the skin, and the number of SCOUT localized breast excisions performed by operating surgeon up to the 1st five cases. We studied the relationship between these independent variables and the following dependent variables: reflector detection post-placement, reflector detection pre-incision, and reflector localization post-incision.Statistical analysis utilized the z-test to perform a two-sided test of equality at an alpha level of 0.05 with adjustment for multiple comparisons by the Bonferroni method. T-tests were used to perform two-sided tests of equality for numeric variables. Results: Across 11 institutions, 16 surgeons performed a total of 153 surgical excisions. Overall success rates of reflector detection pre-incision and post-incision were 98% (150/153) and 99% (151/153), respectively. The reflectors were successfully removed in 100% (153/153) of cases. Difficulty with reflector detection immediately post placement was significantly associated with reflectors more than 4 cm (P=0.034) or 5 cm (P=0.007) from the skin, or the procedure being the 1st SCOUT case by the operating surgeon (P=0.036). Operating surgeons performing their 1st SAVI localization procedure were significantly associated with difficult reflector detection post-incision (p=0.044). Subsequent procedures, up to the first five SCOUT localizations, noted no significant difficulty with reflector detection. Conclusions: The SAVI SCOUT surgical guidance system is a viable surgical localization procedure for non-palpable breast lesions. Surgeons were 100% successful at removing the reflectors during surgical excision. Difficulty with reflector detection was not noted after the surgeon's 1st SCOUT procedure. Overall, it appears the learning curve for reflector placement and localization for non-palpable breast lesions is relatively short. However, depth of the reflector in relation to skin likely affects reflector detection during this early learning period. Citation Format: Shukla SC, Shivers SC, Mattingly A, Russell S, Mehindru A, Carter E, Cox CE. Learning curve for the SAVI SCOUT breast localization and surgical guidance system [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-11-06.

The effect of electromagnetic guidance system on early learning curve of ultrasound for novices

BackgroundElectromagnetic guidance reveals needle alignment and position relative to the image plane on an ultrasound view. This study compared the early learning curves of novices performing ultrasound-guided needle placement with (n = 10) or without electromagnetic guidance (n = 10).MethodsParticipants performed 30 ultrasound-guided needle placements using an echogenic stick (0.3-cm diameter) as a target inside a phantom model; this early learning period was divided into sequential periods (P1: 1–5, P2: 6–10, P3: 11–15, P4: 16–20, P5: 21–25, P6: 26–30 attempts).ResultsUsing an in-plane approach, the time required for needle placement in the EMG group was significantly shorter than that of the non-EMG group in P1, P2, P4, and P6 and the number of needle advances of the EMG group was significantly smaller than that of the non-EMG group in P1 and P2. Using an out-of-plane approaches, the time required for needle placement in the EMG group was significantly shorter than that of the non-EMG group in all periods, but the number of needle advances was similar between both groups in P1–P5.ConclusionsThe electromagnetic guidance system may be beneficial when performing ultrasound guided peripheral nerve blocks or vascular cannulation in the early learning period, especially by inexperienced operators with reducing patient risk.

Learning Curve Associated with Complications in Biportal Endoscopic Spinal Surgery: Challenges and Strategies.

Study DesignDescriptions of technical strategies to overcome pitfalls associated with early learning periods in biportal endoscopic spinal surgery (BESS).PurposeTo introduce BESS for lumbar spinal diseases (LSDs) and to inform certain challenges to be overcome in mastering the technique.Overview of LiteratureBESS has shown superior benefits including excellent magnification, a wider range of view by dynamic handling of an endoscope and instruments. Clinical reports, however, have not yet been very revealing for its new introduction into minimally invasive spine surgery.MethodsTo evaluate the learning curve for BESS, the procedures for various LSDs by one surgeon were analyzed in the view of shortening of the operating times and reduction of complications. Reviewing of recorded procedures helped in finding the reasons and the implemented solutions.ResultsThe 68 cases included 25 for lumbar disc herniation (LDH), 3 for revision for recurred LDH, 39 for lumbar spinal stenosis (LSS) and 1 for synovial cyst. The operation time for the total cases averaged 83.7±33.6 minutes. According to diagnosis, it was 68.2±23.7 minutes for LDH. After the 14th case of LDH, it was nearly constant and close to the average time. One level of LSS needed 110.4±34.4 minutes. Prolonged operation times even in some later cases of LSS were mainly from struggling against blurred vision due to epidural bleeding. There were 7 cases of complications (10.3%) including 2 cases of dural tear, 1 case of root injury, and 4 cases of incomplete decompression on postoperative magnetic resonance imaging. There was no case of symptomatic hematoma or wound infection.ConclusionsBESS seemed to have a relatively short learning curve period. The overall complication rate in early learning period was 10.3%. These could be avoided by magnified regional views on an endoscope and a clear surgical field by controlling epidural bleeding.