Assessment of surgical trainees' quality of knot-tying

Intracorporeal vs. extracorporeal open and closed knot tying techniques in laparoscopy: A randomized, controlled study

Objective

Tying knots during suturing is one of the most challenging tasks in laparoscopic surgery. Therefore, measures aimed at ensuring both the ease and speed of knot tying not only benefit the surgeon but can also reduce operating time significantly. This study compared extracorporeal and intracorporeal knot tying techniques using a Szabo pelvic trainer model from the Gynaecological Endoscopic Surgical Education and Assessment program.

Design

The students tied intra- and extracorporeal knots using closed- and open-jaw knot pushers. Using an artificial tissue suturing pad in a certified Szabo pelvic trainer, students tied three knots using each technique according to block randomization. Task completion time, knot strength, knot-spread ability, and number of errors were recorded. The Wilcoxon test and mixed-effects models were used to analyze the results. After completing the exercises, participants answered a questionnaire concerning knot-tying techniques and their performance.

Setting

University Hospital Basel, which provides tertiary-level clinical care.

Participants

Fifty-seven medical students with no experience in laparoscopy voluntarily signed up for this study.

Results

Open and closed extracorporeal knot tying was significantly faster (p < 0.001, p < 0.001, respectively), more precise (p = 0.007, p = 0.003), and associated with reduced knot-spread ability (p < 0.001, p < 0.001) compared to intracorporeal knot tying. Open- and closed-jaw knot pushers were shown to be equal in terms of speed (p = 0.563), knot-spread ability (p = 0.49), and precision (p = 0.831). The study participants rated open (30 %) and closed (49 %) extracorporeal knot tying as more intuitive than intracorporeal (21 %) knot tying. Improved concentration was significantly correlated with tighter knots (p = 0.011).

Conclusions

Students achieved significantly better results using extracorporeal knot-tying techniques than intracorporeal ones, including greater speed, tighter knots, and optimized precision. These results suggest that beginners in the field of laparoscopy should be encouraged to practice extracorporeal knot-tying techniques.

Laparoscopic Surgery: A Systematic Review of Loop and Knot Security, Varying with the Suture and Sequences, Throws, Rotation and Destabilization of Half-Knots or Half-Hitches

Surgical knots are sequences of half-knots (H) or half-hitches (S), defined by their number of throws, by an opposite or similar rotation compared with the previous one, and for half-hitches whether they are sliding (s) or blocking (b). Opposite rotation results in (more secure) symmetric (s) knots, similar rotation in asymmetric (a) knots, and changing the active and passive ends has the same effect as changing the rotation. Loop security is the force to keep tissue together after a first half-knot or sliding half-hitches. With polyfilament sutures, H2, H3, SSs, and SSsSsSs have a loop security of 10, 18, 28, and 48 Newton (N), respectively. With monofilament sutures, they are only 7, 16, 18, and 25 N. Since many knots can reorganize, the definition of knot security as the force at which the knot opens or the suture breaks should be replaced by the clinically more relevant percentage of clinically dangerous and insecure knots. Secure knots with polyfilament sutures require a minimum of four or five throws, but the risk of destabilization is high. With monofilament sutures, only two symmetric+4 asymmetric blocking half-hitches are secure. In conclusion, in gynecology and in open and laparoscopic surgery, half-hitch sequences are recommended because they are mandatory for monofilament sutures, adding flexibility for loop security with less risk of destabilization.

Arthroscopic knots: Suture and knot characterisation of modern polyblend suture materials

Objective

The primary aim of this study was to explore the relationship between the biophysical structure and function of modern suture materials. Particularly the suture's ability to withstand the stressors of surgery and how the material properties affect knot stability. The secondary aim was to investigate the effect that different knots have on the suture material itself. This study builds on previous research assessing suture and knot characteristics but in modern Ultra High Molecular Weight Polyethylene (UHMWPE) materials currently in widespread clinical use in arthroscopic surgery.

Methods

Three common UHMWPE sutures and one polyester suture were tested in both a dry and wet state using the Geelong, Nicky's, Surgeon's and Tautline knots. Tensile strength of knots was tested vertically at a 60 mm/min strain rate and 45 mm gauge length. Sutures were tied through a cannula around two 8 mm diameter circular bollards. Testing was conducted in a controlled environment temperature and humidity environment (20 ± 2 °C, 65 ± 2%).

Results

No one knot type was optimal over all suture types. Mean tensile strength in both a dry and wet state and a low coefficient of variation (CV) in tensile strength in a wet state were considered as an indication of suitability. With Ethibond sutures this was the Geelong knot (CV:4.2%). With Orthocord sutures both the Geelong and Tautline knots (CV:4.2% and CV:11.9% respectively). With FiberWire sutures the Nickys and Tautline knots (CV:22.6% and CV:22.5% respectively). With ForceFiber sutures all four knots exhibited similar wet tensile strength with high variability showing that all should perform in a similar way invivo.

Conclusions

This study demonstrates a statistically significant three-way interaction between polyblend suture materials, the knot and the environment. This has implications for knot security using the tested sutures in different environments, as one knot may not behave the same under all conditions.

The strength of surgical knots involves a critical interplay between friction and elastoplasticity

Knots are the weakest link in surgical sutures, serving as mechanical ligatures between filaments. Exceeding their safe operational limits can cause fatal complications. The empirical nature of present guidelines calls for a predictive understanding of the mechanisms underlying knot strength. We identify the primary ingredients dictating the mechanics of surgical sliding knots, highlighting the previously overlooked but critical effect of plasticity and its interplay with friction. The characterization of surgeon-tied knots reveals the relevant ranges of tightness and geometric features. Using model experiments coupled with finite element simulations, we uncover a robust master curve for the target knot strength versus the tying pre-tension, number of throws, and frictional properties. These findings could find applications in the training of surgeons and robotic-assisted surgical devices.

Does quality of novice hand-tied square knots improve with repetition during a single training session?

Background

Knot tying is a key surgical skill for novices, and repetition over several training sessions improves knot tying. This study examined the effects of repetition within a single training session on quality of knotted loops and compared results of novice trainees and experienced surgeons.

Methods

Using 0.55 mm nylon monofilament fishing line, novices and surgeons each hand-tied 20 knotted loops, using a 2=1=1=1 configuration (surgeon's throw and three square throws). Loops were mechanically tested with a single load to failure.

Results

All loops tolerated five newtons (N) preload. More than 70% of novice and surgeon knots failed by slipping or untying, and 8.8% of novice knots and 2.5% of surgeon's knots were considered dangerous. Surgeons' loops had less extension at preload, indicating better loop security. However, during single test to failure, there was no difference in mean extension or maximum load between surgeons and novices. There was no significant difference in results of mechanical testing or modes of failure for the first and last ten knotted loops, or the first, second, third, and fourth sets of knotted loops.

Discussion

With appropriate training, novices can construct knots as strong and secure as experienced surgeons. A large percentage of knotted loops are insecure under testing conditions; extra throws may be required when using large diameter monofilament nylon. Novices may require extra training in maintenance of loop security when constructing square knots. Tying more than five or 10 knotted loops within a single training session does not provide added benefits for novices.

How to tie dangerous surgical knots: easily. Can we avoid this?

Objective

Secure knots are essential in all areas of surgical, medical and veterinary practice. Our hypothesis was that technique of formation of each layer of a surgical knot was important to its security.

Design

Equal numbers of knots were tied, by each of three groups, using three techniques, for each of four suture materials; a standard flat reef knot (FRK), knots tied under tension (TK) and knots laid without appropriate hand crossing (NHCK). Each knot technique was performed reproducibly, and tested by distraction with increasing force, till each material broke or the knot separated completely.

Setting

Temporary knot tying laboratory.

Materials

The suture materials were, 2/0 polyglactin 910 (Vicryl), 3/0 polydioxanone, 4/0 poliglecaprone 25 (Monocryl) and 1 nylon (Ethilon).

Participants

Three groups comprised, a senior surgeon, a resident surgeon and three medical students.

Outcome measures

Proportion of each knot type that slipped, degree of slippage and length of suture held in loop secured by each knot type.

Results

20% of FRK tied with all suture materials slipped; all knots tied with the other two techniques, with all materials, slipped, TK (100%) and NHCK (100%). The quantitative degree of slip was significantly less for FRK (mean 6.3%–, 95% CI 2.2% to 10.4%) than for TK (mean 312%, 95% CI 280.0% to 344.0%) and NHCK (mean 113.0%, –95% CI 94.3% to 131.0%).

The mean length of suture in loops held within (FRK mean 25.1 mm 95% CI 24.2 to 26.0 mm) was significantly greater than mean lengths held by the other techniques (TK mean 17.0 mm, 95% CI 16.3 to 17.7 mm), (NHCK mean 16.3 mm, 95% CI 15.9 to 16.7 mm). The latter two types of knot may have tightened more than anticipated, in comparison to FRK, with potential undue tissue tension.

Conclusion

Meticulous technique of knot tying is essential for secure knots, appropriate tissue tension and the security of anastomoses and haemostasis effected.

The Spaced Learning Concept Significantly Improves Acquisition of Laparoscopic Suturing Skills in Students and Residents: A Randomized Control Trial

INTRODUCTION

 Spaced learning consists of blocks with highly condensed content that interrupted by breaks during which distractor activities, such as physical activity, are performed. The concept has been shown to be superior in complex motor skill acquisition like laparoscopic suturing and knot tying. Preliminary studies have solely been conducted with medical students. Therefore, it remained unanswered if the spaced learning concept would also work for pediatric surgery residents.

MATERIALS AND METHODS

 The study aimed to evaluate the effectiveness of spaced learning, students, and residents were asked to perform four surgeons' square knots on a bowel model within 30 minutes prior and post 3 hours of hands-on training. To examine the long-term skills, the same subjects were asked to perform a comparable, but more complex task 12 months later without receiving training in the meantime. Total time, knot stability, suture accuracy, knot quality, and laparoscopic performance were assessed. Additionally, motivation was accessed by using the questionnaire on current motivation. Differences were calculated using mixed analysis of variance, Mann-Whitney U test, and multivariate analysis of covariance.

RESULTS

 A total of 20 medical students and 14 residents participated in the study. After randomization, 18 were trained using the spaced learning concept and 16 via conventional methods. Both groups had comparable baseline characteristics and improved significantly after training in all assessed measures. The spaced learning concept improved procedure performance as well as knot quality and stability in both students and residents. However, residents that trained via spaced learning showed significantly better long-term results regarding knot quality and speed in comparison to students. Although anxiety was significantly reduced in both training groups over time, residents were significantly more interested regarding knot tying than students.

CONCLUSION

 This study dispels any remaining doubt that the spaced learning concept might only work for medical students. It appears that the spaced learning concept is very suitable for residents in acquiring complex motor skills. It is superior to conventional training, resulting in improved procedural performance as well as knot quality and speed. Hence, tailored training programs should not only be integrated early on in students' curricula but also in surgical training programs.

Learning and optimizing arthroscopic knot-tying by surgery residents using procedural simulation

INTRODUCTION

Procedural training of orthopedic surgery residents includes learning arthroscopic knot-tying. The models used comprise arthroscopy training modules of increasing complexity, although there is no procedural training guide for the acquisition of arthroscopic knot-tying skills. Few studies have focused on how residents learn arthroscopic knot-tying. The aim of our study was to determine the type of arthroscopic knot that is the easiest to perform and learn and that can be done the most successfully by orthopedic surgery residents.

MATERIALS AND METHODS

Each participant had to learn five knots in a random order: Tennessee slider, Duncan loop, Revo knot (Surgeon's knot), Nicky knot, and the SMC (Samsung Medical Center) knot. The FAST Arthroscopy Workstation™ (Sawbones, Vashon Island, WA) was used for this study. Each participant could use a FAST Knot Tester™ (Sawbones®, Vashon Island, WA) to evaluate by themselves the biomechanical properties of the knots to optimize learning. Each participant had to rank how easy it was to learn this knot on a visual scale from 0 to 10. They also had to rank the reliability of the knots done on a visual scale from 0 to 10. Then, an independent rater assessed whether the knots were completed successfully; a knot was considered successful if it stretched by less than 3 mm when 60 N of load was applied.

RESULTS

Ten participants were included in the study; 250 knots were done and evaluated. When ranked from simplest to most complicated, the easiest knot to learn was the Surgeon's knot, followed by the Duncan loop, Tennessee slider, Nicky knot and SMC knot (p<0.0001). The overall success rate for the knots was 80%. There was a statistical trend for the Nicky being done better than the other arthroscopic knots (88% success rate).

CONCLUSION

For orthopedics surgery residents, the surgeon's knot (Revo knot) was the easiest to learn, while the Nicky knot had the highest success rate.

LEVEL OF EVIDENCE

II; prospective, randomized study with low power.

Smart surgical sutures using soft artificial muscles

Wound closure with surgical sutures is a critical challenge for flexible endoscopic surgeries. Substantial efforts have been introduced to develop functional and smart surgical sutures to either monitor wound conditions or ease the complexity of knot tying. Although research interests in smart sutures by soft robotic technologies have emerged for years, it is challenging to develop a soft robotic structure that possesses a similar physical structure as conventional sutures while offering a self-tightening knot or anchor to close the wound. This paper introduces a new concept of smart sutures that can be programmed to achieve desired and uniform tension distribution while offering self-tightening knots or automatically deploying secured anchors. The core technology is a soft hydraulic artificial muscle that can be elongated and contracted under applied fluid pressure. Each suture is equipped with a pressure locking mechanism to hold its temporary elongated state and to induce self-shrinking ability. The puncturing and holding force for the smart sutures with anchors are examined. Ex-vivo experiments on fresh porcine stomach and colon demonstrate the usefulness of the new smart sutures. The new approaches are expected to pave the way for the further development of smart sutures that will benefit research, training, and commercialization in the surgical field.

Use of the Fundamentals of Arthroscopic Surgical Training Workstation for Immediate Objective Feedback During Training Improves Hand-Tied Surgical Knot Proficiency: A Randomized Controlled Study

INTRODUCTION

In a prior study, we validated the FAST workstation as an objective evaluator of hand-tied surgical knots. The goal of this study was to determine whether guided practice with the FAST workstation could lead to objective improvement in hand-tied surgical knot performance.

METHODS

Sixty participants were randomized into 1 of 2 groups: a control group, with access to only the knot-tying station, and a test group, with access to the knot-tying station plus the knot testing station. The study was divided into 3 phases: prepractice, practice, and postpractice. Using the FAST workstation, participants hand-tied 5 knots, 15 knots, and 5 knots using 0 Vicryl suture in the prepractice, practice, and postpractice phases, respectively. Knots for each participant from the prepractice and postpractice phases were collected, tested, and compared.

RESULTS

Within the control group, the average number of prepractice knot successes was 2.63, and the average number of postpractice knot successes was 3.40, which resulted in an improvement of average knot successes of 0.77 (P < 0.01). Within the test group, the average number of prepractice knot successes was 2.40, and the average number of postpractice knot successes was 4.10, which resulted in an improvement of average knot successes of 1.70 (P < 0.01). The difference in average improvement of knot-tying successes (0.93 knots) between the 2 groups was statistically significant (P < 0.01).

DISCUSSION

A knot-tying trainer that provides objective feedback on knot performance may better improve hand-tied surgical knot proficiency compared with one without objective feedback.

Effectiveness of tutorial videos combined with online classes in surgical knotting course during COVID-19 pandemic: A cohort study

Background

COVID-19 pandemic has changed medical education from offline courses to online formats. Nowadays, offline skill demonstration lessons becomes unfeasible. This study assess the effectiveness of tutorial videos and online classes in delivering knowledge and skill in basic surgical knotting to medical students.

Methods

A group of medical students (n = 95) was divided into two groups: the first group was allowed to watch the tutorial video that we have been made and uploaded into YouTube (https://www.youtube.com/watch?v=WyfOVGhAeVA) while the other group did not watch the video. All participants submitted a demonstration video to show their knotting skill. These videos were graded and made into the first evaluation. Then, all participants attended online classes for the surgical knotting skills via Zoom application. Participants submitted another demonstration video after the online classes. The videos were assessed, and the results were analyzed.

Results

The experimental group (n = 50) who watched the tutorial video prior to class scored higher in the first video than the control group (n = 39) with a meanscore of 10.850 versus 7.462, p = 0.000*, In the second video, the assessment showed no significant difference between the two groups with meanscore of 11.220 versus 10.897, p = 0.706.

Conclusion

The combination of tutorial videos and online classes is the optimal teaching method for surgical knotting skills.

•

E-learning becomes a favorable learning method in COVID-19 pandemic era.

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Combination of tutorial video and live online skill demonstration is proven effective in teaching surgical knotting skills to medical students.

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Recording individual skill and individual feedback sessions is the optimal teaching method for surgical knotting skills.

Differences of tensile strength in knot tying technique between orthopaedic surgical instructors and trainees

BACKGROUND

Knot tying technique is an extremely important basic skill for all surgeons. Clinically, knot slippage or suture breakage will lead to wound complications. Although some previous studies described the knot-tying technique of medical students or trainees, little information had been reported on the knot-tying technique of instructors. The objective of the preset study was to assess surgeons' manual knot tying techniques and to investigate the differences of tensile strength in knot tying technique between surgical instructors and trainees.

METHODS

A total of 48 orthopaedic surgeons (postgraduate year: PGY 2-18) participated. Surgeons were requested to tie surgical knots manually using same suture material. They were divided into two groups based on each career; instructors and trainees. Although four open conventional knots with four throws were chosen and done with self-selected methods, knot tying practice to have the appropriate square knots was done as education only for trainees before the actual trial. The knots were placed over a 30 cm long custom made smooth polished surface with two cylindrical rods. All knots were tested for tensile strength using a tensiometer. The surgical loops were loaded until the knot slipped or the suture broke. The tensile strength of each individual knot was defined as the force (N) required to result in knot failure. Simultaneously, knot failure was evaluated based on knot slippage or suture rupture. In terms of tensile strength or knot failure, statistical comparison was performed between groups using two-tailed Mann-Whitney U test or Fisher exact probability test, respectively.

RESULTS

Twenty-four instructors (PGY6-PGY18) and 24 trainees (PGY2-PGY5) were enrolled. Tensile strength was significantly greater in trainees (83.0 ± 27.7 N) than in instructors (49.9 ± 34.4 N, P = 0.0246). The ratio of slippage was significantly larger in instructors than in trainees (P < 0.001). Knot slippage (31.8 ± 17.7 N) was significantly worse than suture rupture (89.9 ± 22.2 N, P < 0.001) in tensile strength.

CONCLUSIONS

Mean tensile strength of knots done by trainees after practice was judged to be greater than that done by instructors in the present study. Clinically, knot slippage can lead to wound dehiscence, compared to suture rupture.

Assessment of time to completion, number of errors, and knot-holding capacity of square knots and Aberdeen knots tied by veterinary students and student perceptions of knot security and knot-tying difficulty

OBJECTIVE

To assess the time to completion, number of errors, and knot-holding capacity (KHC) for starting and ending square knots (SSKs and ESKs) of a continuous pattern and Aberdeen knots tied by veterinary students and to investigate student perceptions of knot security and knot-tying difficulty for the 3 knot types.

SAMPLE

16 second-year veterinary students.

PROCEDURES

Students created 3 (4-throw) SSKs, 3 (5-throw) ESKs, and 3 (3 + 1 configuration) Aberdeen knots with 2-0 polydioxanone on a custom test apparatus. Time to complete each knot, the number of errors in each knot, and student ratings of knot-tying difficulty and confidence in knot security were recorded. Each knot was tested to failure on a uniaxial tensiometer to determine KHC and mode of failure. Variables of interest were compared by repeated-measures ANOVA or the Friedman test with post hoc pairwise comparisons.

RESULTS

Mean knot completion time for Aberdeen knots was significantly less than mean completion time for SSKs or ESKs. Mean KHC was significantly lower for ESKs than for SSKs; KHC for Aberdeen knots was not compared with these values because of methodological differences. Median error rate was higher for ESKs than for other knot types. Mean difficulty rating for Aberdeen knots was lower than that for ESKs. Most tested knots failed by breakage at the knot.

CONCLUSIONS AND CLINICAL RELEVANCE

Aberdeen knots appeared to be easy for veterinary students to learn and were completed more rapidly and with fewer errors than ESKs. Including this type of knot in surgical skills curriculum for novices may be beneficial.

Towards Development of an Open Surgery Competency Assessment for Residents (OSCAR) Tool - A Systematic Review of the Literature and Delphi Consensus

OBJECTIVE

Competency-based education has mandated accurate intra-operative assessment tools. We aimed to define consensus-based open surgical skills perceived by experts as critical for assessment.

DESIGN

A mixed-method design was employed: systematic review and e-Delphi methodology.

SETTING

The study was performed at McGill University-affiliated large tertiary academic centers in Montreal, Quebec, Canada.

PARTICIPANTS

Per PRISMA guidelines, a peer-reviewed search strategy was employed. Studies published in English and those describing technical skill assessment of open abdominal surgery were included; subspecialty-specific skills, conference abstracts, academic memoirs were excluded. Most-cited skills were subjected to e-Delphi methodology to identify those deemed essential by experts, based a 3-point Likert scale. Eighteen McGill University-affiliated general surgeons, representing a variety of subspecialties of General Surgery, were invited to answer the questionnaire.

RESULTS

Around 120 of 4285 references were retained for analysis. The 12 most cited skills included suturing, tissue and instrument handling, movement economy, instrument knowledge, knot tying, flow, knowledge of procedure, completion time, dissection technique, knowledge of anatomy and sterile technique; 6 of these achieved high or perfect scores and agreement after 2 rounds of survey: suturing, sterile technique, knot tying, knowledge of anatomy, knowledge of procedure, and tissue handling. Median standard deviation decreased (0.495 to 0.450) from first to second round, indicating improvement in consensus.

CONCLUSION

These results will help develop and validate the OSCAR (objective structured clinical assessment rubric) assessment tool for immediate intra-operative feedback of open technical skills for surgical trainees.

Novel quantitative and objective structured assessment of technical skill for slip knotting

OBJECTIVE

Currently, no quantitative and objective method has been established for evaluating competencies in basic surgical techniques. The aim of this study was to develop a structured assessment tool for slip knotting and verify how well current board certification system discriminates the level of basic surgical skill.

METHODS

We examined 171 cardiovascular surgical fellows using a novel assessment method for slip knotting that was developed by the committee of the Under-Forty of the Japanese Society of Cardiovascular Surgery. We compared the scores and examinees' surgical experience for validation. We analyzed the relationship between board certification and the scores.

RESULTS

The scores differentiated the general surgical board-certified surgeons from those without certification. Surgical experiences such as training years and number of operated cases and scores were correlated. Among the board-certified surgeons, the group with daily off-the-job training, or simulator-based skill training had a significantly higher mean score (67.4 ± 3.0 vs 55.4 ± 3.1, p = 0.008) and lower rate of poor scorers (7.1% vs 38.5%, p = 0.004). A multivariate analysis revealed that board certification did not predict high scores. Daily off-the-job training was the only independent predictor of high scores (odds ratio: 2.41, 95% confidence interval: 0.01-1.20, p = 0.014).

CONCLUSIONS

This novel quantitative and objective assessment tool for technical skill in slip knotting was found to be valid to examine the skill for slip knotting. In this study, current board certification discriminated the level of basic surgical skill. However, it could not distinguish extremely low scorers perfectly. Some board-certified surgeons showed poor technical competency, especially those without off-the-job training.

Comparison of knot-tying proficiency and knot characteristics for square and reversing half hitch alternating-post surgical knots in a simulated deep body cavity among notice medical students

BACKGROUND

Proficiency-based knot-tying curricula have been developed for square knots for medical students, but, to our knowledge, no such curriculum exists for the reverse half hitch alternating-post (RHAP) knot. We aimed to compare medical students' knot-tying proficiency, knot-tying self-confidence and final knot characteristics for RHAP and square knots in a simulated deep body cavity.

METHODS

We performed a within-subject prospective crossover study of novice medical students who received 30 minutes of training in tying both RHAP and square knots. Participant performance was assessed via a knot-tying checklist, and knot configuration, tensile strength, tightness (loop circumference) and mechanism of failure were also assessed. Participants' self-reported confidence in knot tying was captured.

RESULTS

Twenty-one students participated in the study. Mean scores on the knot-tying checklist were significantly higher for RHAP knots than for square knots (6.9 [standard deviation (SD) 2.1] v. 5.2 [SD 2.3], p < 0.01), and RHAP knots were significantly tighter than square knots (46.8 mm [SD 0.4 mm] v. 49.3 mm [SD 0.7 mm], p < 0.05). There were no differences between RHAP and square knots in correct knot configuration, breaking strength or mechanism of failure. Reverse half hitch alternating-post knots were easier to tie within a deep-body cavity, whereas square knots were easier to learn.

CONCLUSION

Novice medical students were more proficient in tying RHAP knots than square knots in a simulated deep body cavity. Students were able to construct RHAP knots more securely and reported increased confidence in tying RHAP knots at depth compared to square knots.

Validation of the FAST Workstation as an Objective Evaluator of Hand-Tied Surgical Knots

INTRODUCTION

Hand-tying surgical knots is an important skill that is applicable across all surgical disciplines. Knot quality is traditionally assessed in the operating room by visual inspection, which is inherently subjective. With the increasing prevalence of simulation training, surgical trainees having access to objective feedback of their knot-tying skills are paramount for skill evaluation. Our study aimed to validate a mechanical suture loop security tester as an objective evaluation method of hand-tied surgical knot quality.

METHODS

Seventy-three subjects were recruited and categorized based on surgical expertise into one of the following three groups: medical students, surgical residents, and attending surgeons. They hand-tied five surgical knots consecutively using 0 Vicryl sutures. The knots were tested using the suture loop security workstation with 10 lbs of linear force for 10 seconds. Success of the suture loop was set at less than 3 mm of loop expansion. This protocol was based on previous research showing that 3 mm of loop expansion would represent clinical failure of the knot in vivo.

RESULTS

The students, residents, and attending surgeons tied a median of two, three, and four successful knots, respectively. Post hoc pairwise comparisons revealed that residents tied more successful knots than students (p < 0.001), and attending physicians tied more successful knots than students (p < 0.001). However, there was no statistically significant difference in the number of successes between residents and attending physicians (p = 0.24).

CONCLUSIONS

Using the mechanical loop security workstation demonstrates construct validity as a reliable objective evaluation tool of hand-tied surgical knots.

Frequency and cause of transient QT prolongation after surgery

Patients undergoing surgery are often exposed to QT-inciting factors that may increase the risk for complications. We evaluated the clinical characteristics and outcomes of patients with QTc ≥500 ms within the first 24 hours after surgery as identified by an institution-wide electrocardiogram alert system. From November 2010 to June 2011, 470 patients exhibited an electrocardiographically isolated QTc ≥500 ms. QT prolongation after surgery was the setting for >1 of every 10 QTc alerts (59 patients). We determined the presence of QT prolonging medical conditions, drugs, electrolyte abnormalities, and the surgical patient's clinical outcome. The average preoperative QTc of the 59 patients demonstrating perioperative QT prolongation was 463 ± 56 ms with a postoperative QTc increase of 54 ± 37 ms. Most patients (n = 48, 83%) had ≥1 known QT-inciting factor before surgery. Compared with presurgical findings, there was a significant increase in pro-QTc score after surgery (1.8 ± 1.5 vs 3.5 ± 2.0, p <0.01) indicating a greater burden of perioperative QT-inciting factors. In conclusion, nearly all cases of QT prolongation could be explained by known etiologic or iatrogenic factors suggesting that maladaptive cardiac repolarization is most likely not a transient, postoperative stress response and may be avoided by altering clinical management.

Objective Assessment of Knot-Tying Proficiency With the Fundamentals of Arthroscopic Surgery Training Program Workstation and Knot Tester

PURPOSE

To assess a new method for biomechanical assessment of arthroscopic knots and to establish proficiency benchmarks using the Fundamentals of Arthroscopic Surgery Training (FAST) Program workstation and knot tester.

METHODS

The first study group included 20 faculty at an Arthroscopy Association of North America resident arthroscopy course (19.9 ± 8.25 years in practice). The second group comprised 30 experienced surgeons attending an Arthroscopy Association of North America fall course (17.1 ± 19.3 years in practice). The training group included 44 postgraduate year 4 or 5 orthopaedic residents in a randomized, prospective study of proficiency-based training, with 3 subgroups: group A, standard training (n = 14); group B, workstation practice (n = 14); and group C, proficiency-based progression using the knot tester (n = 16). Each subject tied 5 arthroscopic knots backed up by 3 reversed hitches on alternating posts. Knots were tied under video control around a metal mandrel through a cannula within an opaque dome (FAST workstation). Each suture loop was stressed statically at 15 lb for 15 seconds. A calibrated sizer measured loop expansion. Knot failure was defined as 3 mm of loop expansion or greater.

RESULTS

In the faculty group, 24% of knots "failed" under load. Performance was inconsistent: 12 faculty had all knots pass, whereas 2 had all knots fail. In the second group of practicing surgeons, 21% of the knots failed under load. Overall, 56 of 250 knots (22%) tied by experienced surgeons failed. For the postgraduate year 4 or 5 residents, the aggregate knot failure rate was 26% for the 220 knots tied. Group C residents had an 11% knot failure rate (half the overall faculty rate, P = .013).

CONCLUSIONS

The FAST workstation and knot tester offer a simple and reproducible educational approach for enhancement of arthroscopic knot-tying skills. Our data suggest that there is significant room for improvement in the quality and consistency of these important arthroscopic skills, even for experienced arthroscopic surgeons.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

Evaluation of surgical training in the era of simulation

AIM

To assess where we currently stand in relation to simulator-based training within modern surgical training curricula.

METHODS

A systematic literature search was performed in PubMed database using keywords "simulation", "skills assessment" and "surgery". The studies retrieved were examined according to the inclusion and exclusion criteria. Time period reviewed was 2000 to 2013. The methodology of skills assessment was examined.

RESULTS

Five hundred and fifteen articles focussed upon simulator based skills assessment. Fifty-two articles were identified that dealt with technical skills assessment in general surgery. Five articles assessed open skills, 37 assessed laparoscopic skills, 4 articles assessed both open and laparoscopic skills and 6 assessed endoscopic skills. Only 12 articles were found to be integrating simulators in the surgical training curricula. Observational assessment tools, in the form of Objective Structured Assessment of Technical Skills (OSATS) dominated the literature.

CONCLUSION

Observational tools such as OSATS remain the top assessment instrument in surgical training especially in open technical skills. Unlike the aviation industry, simulation based assessment has only now begun to cross the threshold of incorporation into mainstream skills training. Over the next decade we expect the promise of simulator-based training to finally take flight and begin an exciting voyage of discovery for surgical trainees.