The Practice of Knots Untying Technique Using a 10-0 Nylon Suture and Gauze to Cope with Technical Difficulties of Microvascular Anastomosis

Strategies to improve surgical technical competency: a systematic review

BACKGROUND

A cornerstone of surgical residency training is an educational program that produces highly skilled and effective surgeons. Training structures are constantly being revised due to evolving program structures, shifting workforces, and variability in the clinical environment. This has resulted in significant heterogeneity in all surgical resident education, training tools utilized, and measures of training efficacy.

METHODS

We systematically reviewed educational interventions for technical skills in neurosurgery published across PubMed, Embase, and Web of Science over four decades. We extracted general characteristics of each surgical training tool while categorizing educational interventions by modality and neurosurgical application.

RESULTS

We identified 626 studies which developed surgical training tools across eight different training modalities: textbooks and literature (11), online resources (53), didactic teaching and one-on-one instruction (7), laboratory courses (50), cadaveric models (63), animal models (47), mixed reality (166), and physical models (229). While publication volume has grown exponentially, a majority of studies were cited with relatively low frequency. Most training programs were published in the development and validation phase with only 2.1% of tools implemented long-term. Each training modality expressed unique strengths and limitations, with limited data reported on the educational impact connected to each training tool.

CONCLUSIONS

Numerous surgical training tools have been developed and implemented across residency training programs. Though many creative and cutting-edge tools have been devised, evidence supporting educational efficacy and long-term application is lacking. Increased utilization of novel surgical training tools will require validation of metrics used to assess the training outcomes and optimized integration with clinical practice.

Seven bypasses simulation set: description and validity assessment of novel models for microneurosurgical training

OBJECTIVE

Microsurgical training remains indispensable to master cerebrovascular bypass procedures, but simulation models for training that accurately replicate microanastomosis in narrow, deep-operating corridors are lacking. Seven simulation bypass scenarios were developed that included head models in various surgical positions with premade approaches, simulating the restrictions of the surgical corridors and hand positions for microvascular bypass training. This study describes these models and assesses their validity.

METHODS

Simulation models were created using 3D printing of the skull with a designed craniotomy. Brain and external soft tissues were cast using a silicone molding technique from the clay-sculptured prototypes. The 7 simulation scenarios included: 1) temporal craniotomy for a superficial temporal artery (STA)-middle cerebral artery (MCA) bypass using the M4 branch of the MCA; 2) pterional craniotomy and transsylvian approach for STA-M2 bypass; 3) bifrontal craniotomy and interhemispheric approach for side-to-side bypass using the A3 branches of the anterior cerebral artery; 4) far lateral craniotomy and transcerebellomedullary approach for a posterior inferior cerebellar artery (PICA)-PICA bypass or 5) PICA reanastomosis; 6) orbitozygomatic craniotomy and transsylvian-subtemporal approach for a posterior cerebral artery bypass; and 7) extended retrosigmoid craniotomy and transcerebellopontine approach for an occipital artery-anterior inferior cerebellar artery bypass. Experienced neurosurgeons evaluated each model by practicing the aforementioned bypasses on the models. Face and content validities were assessed using the bypass participant survey.

RESULTS

A workflow for model production was developed, and these models were used during microsurgical courses at 2 neurosurgical institutions. Each model is accompanied by a corresponding prototypical case and surgical video, creating a simulation scenario. Seven experienced cerebrovascular neurosurgeons practiced microvascular anastomoses on each of the models and completed surveys. They reported that actual anastomosis within a specific approach was well replicated by the models, and difficulty was comparable to that for real surgery, which confirms the face validity of the models. All experts stated that practice using these models may improve bypass technique, instrument handling, and surgical technique when applied to patients, confirming the content validity of the models.

CONCLUSIONS

The 7 bypasses simulation set includes novel models that effectively simulate surgical scenarios of a bypass within distinct deep anatomical corridors, as well as hand and operator positions. These models use artificial materials, are reusable, and can be implemented for personal training and during microsurgical courses.

Continuous Interrupted Double Throw Suturing Method: A Novel Suturing Technique for Extracranial-Intracranial Bypass

OBJECTIVE

Despite failure of the EC/IC Bypass Study Group to demonstrate effectiveness in minimizing future stroke events, superior temporal artery-medial cerebral artery (STA-MCA) bypass remains an essential treatment for complex giant intracranial aneurysms, tumors, moyamoya disease with ischemia, and atherosclerotic steno-occlusive disease with hemodynamic cerebrovascular insufficiency. The objective of this report is to describe a novel suturing technique for STA-MCA bypass that helps reduce donor-recipient anastomosis time, allowing for a well-organized systematic workflow.

METHODS

Step 1 involves passing the needle of a 9-0 polypropylene suture from out-to-in on the donor vessel followed by in-to-out on the recipient vessel. Step 2: Before cutting and tying a knot as per the established method of suturing, repeat step 1 and leave the needle "parked", creating a loop that is then cut at its proximal end. Step 3: Tie knots using the jeweler's forceps. Repeat previous steps until there are enough throws to seal the bypass adequately.

RESULTS

The STA-MCA bypass serves as a principal method for flow augmentation. The technique described here allows for more efficient and organized microsurgical movements reducing vessel tissue manipulation and clamp time.

CONCLUSIONS

We describe a novel technique for interrupted STA-MCA bypass suturing that adds efficiency, safety, organization, and operative ease compared with the conventional method of interrupted vessel suturing.

Developing microsurgical milestones for psychomotor skills in neurological surgery residents as an adjunct to operative training: the home microsurgery laboratory

OBJECTIVE

A variety of factors contribute to an increasingly challenging environment for neurological surgery residents to develop psychomotor skills in microsurgical technique solely from operative training. While adjunct training modalities such as cadaver dissection and surgical simulation are embraced and practiced at our institution, there are no formal educational milestones defined to help residents develop, measure, and advance their microsurgical psychomotor skills in a stepwise fashion when outside the hospital environment. The objective of this report is to describe an efficient and convenient "home microsurgery lab" (HML) assembled and tested by the authors with the goal of supporting a personalized stepwise advancement of microsurgical psychomotor skills.

METHODS

The authors reviewed the literature on previously published simulation practice models and designed adjunct learning modules utilizing the HML. Five milestones were developed for achieving proficiency with each graduated exercise, referencing the Accreditation Council for Graduate Medical Education (ACGME) guidelines. The HML setup was then piloted with 2 neurosurgical trainees.

RESULTS

The total cost for assembling the HML was approximately $850. Techniques for which training was provided included microinstrument handling, tissue dissection, suturing, and microanastomoses. Five designated competency levels were developed, and training exercises were proposed for each competency level.

CONCLUSIONS

The HML offers a unique, entirely home-based, affordable adjunct to the operative neurosurgical education mandated by the ACGME operative case logs, while respecting resident hospital-based education hours. The HML provides surgical simulation with specific milestones, which may improve confidence and the microsurgical psychomotor skills required to perform microsurgery, regardless of case type.

Nonbiological Microsurgery Simulators in Plastic Surgery Training: A Systematic Review

BACKGROUND

Simulation has gained notable recognition for its role as an effective training and assessment modality in the present era of competency-based medical education. Despite the well-documented efficacy of both live and cadaveric animal models, several ethical, financial, and accessibility issues persist with their use. Lower fidelity nonbiological simulators have gained recognition for their ability to circumvent these challenges. This systematic review reports on all prosthetic and virtual reality simulators in use for microsurgery training, with an emphasis on each model's complexity, characteristics, advantages, disadvantages, and validation measures taken.

METHODS

A systematic search was performed using the National Library of Medicine (PubMed), MEDLINE, and Embase databases. Search terms were those pertaining to prosthetic and virtual reality models with relevance to microsurgical training in plastic surgery. Three independent reviewers evaluated all articles retrieved based on strict inclusion and exclusion criteria.

RESULTS

Fifty-seven articles met the inclusion criteria for review, reporting on 20 basic prosthetic models, 20 intermediate models, 13 advanced models, and six virtual reality simulators.

CONCLUSIONS

A comprehensive summary has been compiled of all nonbiological simulators in use for microsurgery training in plastic surgery, demonstrating efficacy for the acquisition and retention of microsurgical skills. Metrics-based validation efforts, however, were often lacking in the literature. As plastic surgery programs continue to innovate, ensure accountability, and safely meet today's training standards, prosthetic simulators are set to play a larger role in the development of a standardized, ethical, accessible, and objectively measurable microsurgery training curriculum for the modern-day plastic and reconstructive surgery resident.

The Role of Low-Cost Microsurgical Training Models and Experience with Exercises Based on a Bovine Heart

BACKGROUND

Microscopic training is essential for development of neurosurgical skills. A range of models is reported in the literature for this purpose, including live animals, exvivo, and synthetic material. Among the factors involved in selection and development of a training station, cost is a decisive one.

METHODS

We present a low-cost model to practice microvascular anastomoses using a bovine heart and an artificial perfusion system. We also present a brief review of laboratory models for microsurgical training, focusing on the costs and reproducibility of the different options.

RESULTS

Exvivo models are a great bridging point between nonbiologic and living animal training models. These models have major similarities to human vessels, such as lumen size and malleability of the arteries. The bovine heart model allowed the residents to gain confidence in handling vascular tissue in a microscopic environment.

CONCLUSIONS

Although these models do not resemble anatomic landmarks in the human brain, the bovine heart model allowed the residents to gain confidence in handling vascular tissue in a microscopic environment.

The Identification of Factors That Influence the Quality of Bypass Anastomosis and an Evaluation of the Usefulness of an Experimental Practical Scale in This Regard

BACKGROUND

Several factors associated with interrupted and continuous suturing techniques affect the quality of bypass anastomosis. It is difficult to determine the impact of these factors during surgery. The primary objective of this study was to evaluate factors with the potential to influence the quality of bypass anastomosis using either interrupted or continuous suturing. A secondary objective was to evaluate the usefulness of a practical scale when comparing interrupted and continuous suturing techniques to improve bypass anastomosis.

METHODS

Interrupted (n = 100) and continuous (n = 100) suturing techniques were used in 200 end-to-side bypasses to a depth of 3 cm and were assessed by 5 neurosurgeons.

RESULTS

Vessel closing time (P < 0.001), stitch distribution (P < 0.001), intima-intima attachment (P < 0.001), and size of the orifice (P < 0.001) had a significant impact on the quality of the bypass regardless of the suturing technique used. The suturing technique used (interrupted or continuous) and positioning of the recipient vessel (vertical or horizontal) did not significantly influence the quality of anastomosis. Using multivariate analysis, the highest statistical significance with regard to bypass quality was attributed to the large size of the orifice and intimal attachment.

CONCLUSIONS

There were advantages and disadvantages to both suturing techniques. The scale was a practical way to measure and improve performance.

Comparative Prospective Study of Microvascular Anastomosis Training by Self-Learning or with Expert Instruction

BACKGROUND

Young neurosurgeons have little opportunity to receive expert feedback while learning microvascular anastomosis. Our objective was to determine the importance of expert feedback. We compared students who studied anastomosis by self-learning with those who studied it with expert feedback. Our second objective was to determine the efficacy of intensive training by comparing the skills of the students with expert feedback with those of neurosurgeons.

METHODS

Twenty-five medical students and 9 neurosurgeons participated. The students were provided with instructional Digital Video Disks (DVDs) and spent 2 weeks practicing gauze fiber microsuturing followed by 6 weeks practicing end-to-side anastomosis using silicone tube. The students assigned to the expert feedback group received weekly feedback through a video call, whereas those in the self-learning group did not. After training, the students completed a final practical examination that was recorded on DVD. The DVDs and procedural products were numbered and distributed to 2 blinded independent expert neurosurgeons for grading. The neurosurgeons completed a similar examination, and their performances were also recorded and compared with those of the medical students.

RESULTS

Compared with the self-learning group, the expert feedback group showed significantly higher anastomosis scores (P = 0.0261) and a nonsignificant tendency toward slower anastomosis times (P = 0.4188). The expert feedback group also achieved significantly higher anastomosis scores than did the neurosurgeons (P = 0.0055).

CONCLUSIONS

Expert feedback improves mastery of microvascular anastomosis. Intensive training with regular expert feedback enables medical students to achieve microvascular anastomosis skills better than those of neurosurgeons.

The impact of neurosurgical procedure on cognitive resources: Results of bypass training

Background:

Neurosurgeons are exposed to unavoidable distractions in their natural operating environment. Distractions can affect both the surgeon's concentration and the safety and duration of the surgery. Such distraction can be studied by applying a simultaneous cognitive task during a surgical procedure.

Methods:

We used a previously described cognitive task: a forward (DF) and backward digit (DB) repetition task to interfere with the surgeon's attention during a training bypass. A pilot study was performed to find suitable digit repetition lengths. For the main experiment, we used four-digit strings. The test task was alternated across two consecutive sutures (n = 153, 8 bypasses), followed by two consecutive control sutures without digit repetition. The duration and the number of correct answers for the digit repetition task were compared to a baseline digit repetition without simultaneous surgery.

Results:

During the bypass surgery, digit repetitions (especially DB) became slower (P < 0.0001). More errors were made during DB compared to DF only during simultaneous bypass (P < 0.0001). However, we found no effect of digit repetition tasks on individual suture times (P = 0.823).

Conclusions:

The ability to engage in simultaneous tasks while performing surgery is diminished. A surgeon with extensive training can withstand external distraction without an effect on performance; however, this is achieved by partially ignoring the simultaneous task. Our data support that during surgery other cognitive tasks should be avoided to ensure safety.

An Affordable Microsurgical Training System for a Beginning Neurosurgeon: How to Realize the Self-Training Laboratory

OBJECTIVE

To provide detailed information about how to realize a self-training laboratory with cost-effective microsurgical instruments, especially pertinent for the novice trainee.

METHODS

Our training model is designed to allow the practice of the microsurgery skills in an efficient and cost-effective manner. A used stereoscopic microscope is prepared for microsurgical training. A sufficient working distance for microsurgical practice is obtained by attaching an auxiliary objective lens. The minimum instrument list includes 2 jeweler's forceps, iris scissors, and alligator clips. The iris scissors and alligator clip provide good alternatives to micro-scissors and microvascular clamp.

RESULTS

The short time needed to set up the microscope and suture the gauze with micro-forceps makes the training model suitable for daily practice. It takes about 15 minutes to suture 10 neighboring fibers of the gauze with 10-0 nylon; thus, training can be completed more quickly.

CONCLUSIONS

We have developed an inexpensive and efficient micro-anastomosis training system using a stereoscopic microscope and minimal micro-instruments. Especially useful for novice trainees, this system provides high accessibility for microsurgical training.

[New simulation technologies in neurosurgery]

The article presents a literature review on the current state of simulation technologies in neurosurgery, a brief description of the basic technology and the classification of simulation models, and examples of simulation models and skills simulators used in neurosurgery. Basic models for the development of physical skills, the spectrum of available computer virtual simulators, and their main characteristics are described. It would be instructive to include microneurosurgical training and a cadaver course of neurosurgical approaches in neurosurgery training programs and to extend the use of three-dimensional imaging. Technologies for producing three-dimensional anatomical models and patient-specific computer simulators as well as improvement of tactile feedback systems and display quality of virtual models are promising areas. Continued professional education necessitates further research for assessing the validity and practical use of simulators and physical models.