Endoscopic Management of Cavernous Carotid Surgical Complications: Evaluation of a Simulated Perfusion Model

The nomogram for predicting nasal bleeding after endoscopic transsphenoidal resection of pituitary adenomas: a retrospective study

Objective

This study aimed to develop and validate a dynamic nomogram to assess the risk of nasal bleeding after endoscopic transnasal transsphenoidal pituitary tumor resection.

Methods

A retrospective analysis was conducted on patients who underwent endoscopic transnasal transsphenoidal pituitary tumor resection from June 2019 to June 2021. Univariate and multivariate logistic regression analyses were used to screen for independent risk factors for nasal bleeding from the training set. A multivariate logistic regression model was established, a nomogram was plotted, and it was validated in an internal validation set. The performance of the nomogram was evaluated based on the receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis (DCA).

Results

The nomogram indicators included anticoagulant use, sphenoid sinus artery injury, nasal irrigation, platelet count (PLT), and constipation. The predictive model had an area under the ROC curve of 0.932 (95% CI: 0.873-0.990) and 0.969 (95% CI: 0.940-0.997) for the training and validation sets, respectively, indicating good discrimination. The calibration curve showed good consistency between the actual and predicted incidence of nasal bleeding (p > 0.05). DCA indicated that the nomogram had good clinical net benefit in predicting postoperative nasal bleeding in patients.

Conclusion

In summary, this study explored the incidence and influencing factors of nasal bleeding after endoscopic transnasal transsphenoidal pituitary tumor resection and established a predictive model to assist clinical decision-making.

Training models and simulators for endoscopic transsphenoidal surgery: a systematic review

Endoscopic transsphenoidal surgery is a novel surgical technique requiring specific training. Different models and simulators have been recently suggested for it, but no systematic review is available. To provide a systematic and critical literature review and up-to-date description of the training models or simulators dedicated to endoscopic transsphenoidal surgery. A search was performed on PubMed and Scopus databases for articles published until February 2023; Google was also searched to document commercially available. For each model, the following features were recorded: training performed, tumor/arachnoid reproduction, assessment and validation, and cost. Of the 1199 retrieved articles, 101 were included in the final analysis. The described models can be subdivided into 5 major categories: (1) enhanced cadaveric heads; (2) animal models; (3) training artificial solutions, with increasing complexity (from "box-trainers" to multi-material, ct-based models); (4) training simulators, based on virtual or augmented reality; (5) Pre-operative planning models and simulators. Each available training model has specific advantages and limitations. Costs are high for cadaver-based solutions and vary significantly for the other solutions. Cheaper solutions seem useful only for the first stages of training. Most models do not provide a simulation of the sellar tumor, and a realistic simulation of the suprasellar arachnoid. Most artificial models do not provide a realistic and cost-efficient simulation of the most delicate and relatively common phase of surgery, i.e., tumor removal with arachnoid preservation; current research should optimize this to train future neurosurgical generations efficiently and safely.

Focused selection of open cerebrovascular cases for residents interested in cerebrovascular neurosurgery

INTRODUCTION

National and international trends continue to show greater emphasis on endovascular techniques for the treatment of cerebrovascular disease. The cerebrovascular neurosurgeon however must be adequately equipped to treat these patients via both open and endovascular techniques.

METHODS

The decline in open cerebrovascular cases for aneurysm clipping has forced many trainees to pursue open cerebrovascular fellowships to increase case volume. An alternative strategy has been employed at our institution, which is early identification of subspecialty focus with resident driven self-selection of open cerebrovascular cases.

RESULTS

This has allowed recent graduates to obtain enfolded endovascular training and a significant number of open cerebrovascular cases in order to obtain competence and exposure.

DISCUSSION

We advocate for further self-selection paradigms supplemented with simulation training in order to obviate the need for extended post-residency fellowships.

Innovative growth and development of a neurological surgery residency cadaveric skull base simulation training program: A single institution experience

OBJECTIVE

Neurosurgical cadaveric and simulation training is a valuable opportunity for residents and fellows to develop as neurosurgeons, further neuroanatomy knowledge, and develop decision-making and technical expertise. The authors describe the growth and development of Oregon Health & Science University (OHSU) Department of Neurological Surgery (NSG) resident hands-on simulation skull base course and provide details of course layout and setup.

METHODS

A three-part surgical simulation series was created to provide training in cadaveric skull base procedures. Course objectives were outlined for participants. Residents participated in NSG hands-on simulation courses (years 2015-2020) and completed annual course curriculum and anonymous course evaluations, which included free text reviews. Courses were evaluated by Likert scale analysis within Python, and free text was quantified using Valence Aware Dictionary for sEntiment Reasoning (VADER). Descriptive statistics were calculated and plotted using Python's Seaborn and Matplotlib library modules.

RESULTS

Analysis included 162 skull base (anterior fossa, middle fossa and lateral, and endoscopic endonasal-based) simulation course evaluations. Resident responses were overwhelmingly positive. Likert responses demonstrated high average responses for each question (4.62 ± 0.56 and above). A positive attitude about simulation courses is supported by an average compound sentiment value of 0.558 ± 0.285.

CONCLUSION

This is the first time Likert responses and sentiment analysis have been used to demonstrate how neurosurgical residents view a comprehensive, multi-year hands-on simulation training program. We hope the information presented serves as a guide for other institutions to develop their own residency educational curriculum in cadaveric skull base procedures.

Development of a management protocol for internal carotid artery injury during endoscopic surgery: a modified Delphi method and single-center multidisciplinary working group

BACKGROUND

Intra-operative internal carotid artery (ICA) injury during transnasal endoscopic surgery is a potentially catastrophic event. Such an injury is life-threatening in the immediate setting, with a reported peri-operative mortality rate of 10%. Nasal packing, muscle patches, direct vessel closure, and endovascular techniques have been described as useful strategies for managing ICA bleeds. The objective of this study was to develop a formalized management protocol for intra-operative ICA injury through engagement with a multi-disciplinary panel.

METHODS

A modified Delphi method including literature review, iterative rounds of stakeholder feedback, and expert panel discussions was used to develop a management protocol for ICA injury during transnasal endoscopic surgery. The 10-person multi-disciplinary panel included otolaryngologists, neurosurgeons, interventional neuroradiologists, anesthesiologists, and operating room nursing staff.

RESULTS

After three rounds of stakeholder engagement with the expert panel, consensus was reached on important elements to include within the protocol. The protocol was divided in three categories: Alert, Control, and Transfer. 'Alert' focusses on early communication with anesthesia and nursing staff. 'Control' focusses on techniques to expose the injury and obtain hemostasis or adequate tamponade. Lastly, 'Transfer' describes the process of contacting neuro-interventional radiology and safely transferring the patient. A one-page handout of the protocol was developed for placement in operating theatres.

CONCLUSION

Due to the life-threatening nature of ICA injury, it is imperative that endoscopic sinus and skull base surgeons are prepared to manage this complication. Using a modified Delphi method with a multidisciplinary expert panel, a protocol for management of intra-operative ICA injury was developed.

Establishing a Multidisciplinary Cavernous Carotid Injury Simulation to Train Neurosurgical, Otolaryngology, and Anesthesia Residents

Carotid artery injuries are serious complications of endoscopic endonasal surgery. As these occur rarely, simulation training offers an avenue for technique and algorithm development in resident learners. This study develops a realistic cadaveric model for the training of crisis resource management in the setting of cavernous carotid artery injury. An expanded endonasal approach and right cavernous carotid injury is performed on a cadaveric head. The cadaver's right common carotid artery is cannulated and connected to a perfusion pump delivering pressurized simulated blood. A simulation mannequin is incorporated into the model to allow for vital sign feedback. Surgical and anesthesia resident learners are tasked with obtaining vascular control with a muscle patch technique and medical management over the course of 3 clinical scenarios with increasing complexity. Crisis management instructions for an endoscopic endonasal approach to the cavernous carotid artery and blood pressure control were provided to the learners prior to beginning the simulation. An independent reviewer evaluated the learners on communication skills, crisis management algorithms, and implementation of appropriate skill sets. After each scenario, residents were debriefed on how to improve technique based on evaluation scores in areas of situational awareness, decision-making, communications and teamwork, and leadership. After the simulation, learners provided feedback on the simulation and this data was used to improve future simulations. The benefit of this cadaveric model is ease of set-up, cost-effectiveness, and reproducibility.

Crisis Management Simulation: The Value of Interdisciplinary Debriefing

OBJECTIVE

Simulation offers an important avenue for surgical and anesthesia training. This is especially important for crisis management scenarios where individuals need to act quickly and efficiently for optimal patient care. Practice based performance can be measured and real time feedback provided during debriefing scenarios.

METHODS

In this paper, we highlight a dual anesthesia and otolaryngology cavernous carotid injury scenario. The trials were run three different times with inter-trial debriefing.

RESULTS

The focused debriefing improved resident performance in terms of blood loss on subsequent trials. Furthermore, the learners provided important feedback regarding the utility of training and how it improved their ability to handle crisis management scenarios in the future.

CONCLUSION

Debriefing for crisis management in a simulation trial improves performance and trainee confidence. Follow up studies will evaluate real world effectiveness over a longer follow up period.

Crisis Management Simulation: Review of Current Experience

Crisis management simulation is important in training the next generation of surgeons. In this review, we highlight our experiences with the cavernous carotid injury model. We then delve into other crisis simulation models available for the neurosurgical specialty. The discussion focuses upon how these trainings can continue to evolve. Much work is yet to be done in this exciting arena and we present several avenues for future discovery. Simulation continues to be an important training tool for the surgical learner.

SimLife model: introducing a new teaching device in endocrine surgery simulation

To evaluate the validity and reliability of an innovative training model for endocrine surgical procedures. A simulator training model for endocrine procedures (SimLife) was developed at an academic center. The model consisted of a realistic operating environment with a coherent simulated patient dynamized by pulsatile vascularization with simulated blood warmed to 37 °C, and ventilation. Training sessions were designed for adrenal and thyroid surgery, as well as neck dissection. The primary outcome of interest was to evaluate learners’ performance and satisfaction. Learners’ performance was evaluated based on a scoring scale that followed the Downing method for the assessment of competency. While learners’ satisfaction was evaluated using a Likert scale of 1 to 10 on four items (ease of learning, anatomic correspondence of landmarks, realism, and overall satisfaction). Participants were engaged in 32 training sessions. These included 24 adrenalectomies (conventional and laparoscopic both transabdominal and posterior), and 4 thyroid lobectomies with concomitant functional lateral compartment neck dissection. competency scores were procedure-specific addressing specific core components of a given procedure. Learners’ performance scored above average in all procedures evaluated. Satisfaction scores for the specified four items ranged between 8.43 (SD 0.87) and 8.89 (SD 0.96). No major events were reported for the adrenalectomies, while only one jugular vein injury occurred during neck dissection. SimLife is a hyper-realistic training model that allows for satisfactory acquisition of skills and the evaluation of performance progression. It has the potential to become a cornerstone in specialized surgical training.

Endoscopic Muscle Repair of Right Internal Carotid Artery Rupture Following Endovascular Procedure

Carotid artery blowout syndrome (CBS) is a deadly complication usually linked to head and neck cancer therapy. We present a different etiology of endoscopic CBS, a complication of endovascular coiling of an intracranial aneurysm, treated with sternocleidomastoid (SCM) muscle graft packing. Case Presentation: An otherwise healthy 55-year-old female presented to the emergency room with right-sided painless vision loss of 23 days. Computed tomography angiography demonstrated a right ophthalmic ICA aneurysm eroding into the right sphenoid sinus with optic nerve compression. Attempted endovascular repair of the aneurysm was complicated by ICA rupture into the sphenoid. An endovascular balloon was inflated proximal to the aneurysm to reduce hemorrhage as ENT performed an endoscopic sphenoidotomy. A hematoma was seen overlying the aneurysm in the superior lateral sphenoid sinus. Layers of SCM muscle were morselized and packed serially. Post-repair angiography showed no further extravasation. Aggressive antiplatelet therapy was initiated. Packing was removed after 14 days. Twenty days postoperatively, the patient had profuse left-sided epistaxis requiring a left sphenopalatine artery ligation. The patient's vision recovered. Discussion: Whereas CBS is often managed by endovascular coil embolism, in our case CBS was caused by this very treatment itself. This case shows the use of SCM muscle graft as an effective repair modality of ICA rupture due to endovascular coiling. Laryngoscope, 131:E764-E766, 2021.

Bariatric Surgical Simulation: Evaluation in a Pilot Study of SimLife, a New Dynamic Simulated Body Model

Background

The demand for bariatric surgery is high and so is the need for training future bariatric surgeons. Bariatric surgery, as a technically demanding surgery, imposes a learning curve that may initially induce higher morbidity. In order to limit the clinical impact of this learning curve, a simulation preclinical training can be offered. The aim of the work was to assess the realism of a new cadaveric model for simulated bariatric surgery (sleeve and Roux in Y gastric bypass).

Aim

A face validation study of SimLife, a new dynamic cadaveric model of simulated body for acquiring operative skills by simulation. The objectives of this study are first of all to measure the realism of this model, the satisfaction of learners, and finally the ability of this model to facilitate a learning process.

Methods

SimLife technology is based on a fresh body (frozen/thawed) given to science associated to a patented technical module, which can provide pulsatile vascularization with simulated blood heated to 37 °C and ventilation.

Results

Twenty-four residents and chief residents from 3 French University Digestive Surgery Departments were enrolled in this study. Based on their evaluation, the overall satisfaction of the cadaveric model was rated as 8.52, realism as 8.91, anatomic correspondence as 8.64, and the model’s ability to be learning tool as 8.78.

Conclusion

The use of the SimLife model allows proposing a very realistic surgical simulation model to realistically train and objectively evaluate the performance of young surgeons.

ICAR: endoscopic skull-base surgery

BACKGROUND

Endoscopic skull-base surgery (ESBS) is employed in the management of diverse skull-base pathologies. Paralleling the increased utilization of ESBS, the literature in this field has expanded rapidly. However, the rarity of these diseases, the inherent challenges of surgical studies, and the continued learning curve in ESBS have resulted in significant variability in the quality of the literature. To consolidate and critically appraise the available literature, experts in skull-base surgery have produced the International Consensus Statement on Endoscopic Skull-Base Surgery (ICAR:ESBS).

METHODS

Using previously described methodology, topics spanning the breadth of ESBS were identified and assigned a literature review, evidence-based review or evidence-based review with recommendations format. Subsequently, each topic was written and then reviewed by skull-base surgeons in both neurosurgery and otolaryngology. Following this iterative review process, the ICAR:ESBS document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:ESBS document addresses the role of ESBS in primary cerebrospinal fluid (CSF) rhinorrhea, intradural tumors, benign skull-base and orbital pathology, sinonasal malignancies, and clival lesions. Additionally, specific challenges in ESBS including endoscopic reconstruction and complication management were evaluated.

CONCLUSION

A critical review of the literature in ESBS demonstrates at least the equivalency of ESBS with alternative approaches in pathologies such as CSF rhinorrhea and pituitary adenoma as well as improved reconstructive techniques in reducing CSF leaks. Evidence-based recommendations are limited in other pathologies and these significant knowledge gaps call upon the skull-base community to embrace these opportunities and collaboratively address these shortcomings.

Development of a Modular Cadaveric Endoscopic Orbital Surgery Model

Introduction

Endoscopic orbital surgery requires the acquisition of unique skill set including endoscopic bimanual dissection of intra/extraconal lesions adherent to orbital fat and neurovascular structures. Our goal was to develop a modular cadaveric model used to train surgeons to resect orbital pathology within any desired orbital compartment.

Methods

Expansile superabsorbent polymer (SAP) beads (2 mm) were soaked in Omnipaque™ (Iohexol) solution for 15 minutes prior to transcaruncular orbital implantation using 10-gauge angiocath. Insertion depth was designed to implant beads in predetermined intraconal compartments corresponding to established orbital tumor stages. Beads were left to expand in situ over a period of 1 to 5 hours. Computed tomography scans were performed using the FUSION image guidance protocol. Model utility and learning curves were assessed by quantifying resection time over 8 sequential attempts.

Results

All 24 beads were successfully implanted in 8 orbits corresponding to CHEER stage II to IV lesions (n = 3 per orbit). Beads expanded from 2 mm to an average of 5.2 mm within 1 hour. During expansion, the beads interpolated into the adjacent fascia similar to in vivo tumors. Average insertion time was 5:53 minutes per orbit (range, 3:24–10:33 min) and average time to bead identification was 10:47 minutes. Across all beads, dissection times decreased in a nonsignificant manner over 8 consecutive attempts.

Conclusion

The directed implantation of expansile SAP beads in this cadaveric model accurately replicates the approach, identification, and resection of isolated orbital lesions. This orbital model can assist the endoscopic surgical team to develop further knowledge and technical skill sets to approach orbital lesions. Further ongoing studies to validate this model are currently underway.

Systematic review of the current status of cadaveric simulation for surgical training

Background

There is growing interest in and provision of cadaveric simulation courses for surgical trainees. This is being driven by the need to modernize and improve the efficiency of surgical training within the current challenging training climate. The objective of this systematic review is to describe and evaluate the evidence for cadaveric simulation in postgraduate surgical training.

Methods

A PRISMA‐compliant systematic literature review of studies that prospectively evaluated a cadaveric simulation training intervention for surgical trainees was undertaken. All relevant databases and trial registries were searched to January 2019. Methodological rigour was assessed using the widely validated Medical Education Research Quality Index (MERSQI) tool.

Results

A total of 51 studies were included, involving 2002 surgical trainees across 69 cadaveric training interventions. Of these, 22 assessed the impact of the cadaveric training intervention using only subjective measures, five measured impact by change in learner knowledge, and 23 used objective tools to assess change in learner behaviour after training. Only one study assessed patient outcome and demonstrated transfer of skill from the simulated environment to the workplace. Of the included studies, 67 per cent had weak methodology (MERSQI score less than 10·7).

Conclusion

There is an abundance of relatively low‐quality evidence showing that cadaveric simulation induces short‐term skill acquisition as measured by objective means. There is currently a lack of evidence of skill retention, and of transfer of skills following training into the live operating theatre.

Simulation Training Methods in Neurological Surgery

Simulation training plays a paramount role in medicine, especially when it comes to mastering surgical skills. By simulating, students gain not only confidence, but expertise, learning to apply theory in a safe environment. As the technological arsenal improved, virtual reality and physical simulators have developed and are now an important part of the Neurosurgery training curriculum. Based on deliberate practice in a controlled space, simulation allows psychomotor skills augment without putting neither patients nor students at risk. When compared to the master-apprentice ongoing model of teaching, simutation becomes even more appealing as it is time-efficient, shortening the learning curve and ultimately leading to error reduction, which is reflected by diminished health care costs in the long run. In this chapter we will discuss the current state of neurosurgery simulation, highlight the potential benefits of this approach, assessing specific training methods and making considerations towards the future of neurosurgical simulation.

Surgical simulation of a catastrophic internal carotid artery injury: a laser-sintered model

BACKGROUND

The catastrophic and rare nature of an internal carotid artery (ICA) injury during endonasal surgery limits training opportunities. Cadaveric and animal simulation models have been proposed, but expense and complicated logistics have limited their adoption. Three-dimensional (3D) printed models are portable, modular, reusable, less costly, and proven to improve psychomotor skills required for managing different lesions. In this study we evaluate the role of a simplified laser-sintered model combined with standardized training in improving the effectiveness of managing an ICA injury endoscopically.

METHODS

A 3-mm defect was created in the parasellar carotid canal of a laser-sintered model representing a sphenoid sinus. Artificial blood was directed to simulate the copious bleeding arising from an ICA injury. Twenty otolaryngologists and 26 neurosurgeons, with varying training and experience levels, were individually asked to stop the "bleeding" as they would in a clinical scenario, and provided no other instructions. This was followed by individualized formative training and a second simulation. Volume of blood loss, time to hemostasis, and self-assessed confidence scores were compared.

RESULTS

At the end of the study, time to hemostasis was reduced from 105.49 seconds to 40.41 seconds (p < 0.001). The volume of blood loss was reduced from 690 to 272 mL (p < 0.001), and the confidence scores increased in 95.7% of participants, from an average of 3 up to 8.

CONCLUSION

This ICA injury model, along with a formal training algorithm, appears to be valuable, realistic, portable, and cost-effective. Significant improvement in all parameters suggests the acquisition of psychomotor skills required to control an ICA injury.

Systematic review of surgical training on reperfused human cadavers

BACKGROUND

The role of reperfused human cadavers in surgical training has not been established.

METHODS

Reports describing reperfused human cadaver models in terms of simulated surgeries, the use of tools to assess technical competency and skills transfer to patients, cadaver status and reperfusion techniques were included.

RESULTS

Thirty-five reports were included. Most participants practised vascular (n = 27), flap (n = 6) and trauma (n = 4) procedures. Training progression was evaluated objectively in only two studies. In two publications, flap techniques were practised on cadavers and repeated successfully in patients. Eighteen studies employed whole bodies. Fresh and embalmed cadavers were both used in 17 publications. Most embalmed cadavers were formalin-fixed (n = 10), resulting in stiffness. Few trainings were offered on soft Thiel-embalmed cadavers (n = 5). Only arteries were reperfused in 20 studies, while in 13 publications, the arteries and veins were filled. Arteries and/or veins were mostly pressurized (n = 21) and arterial flow was generated in 14 studies.

CONCLUSIONS

Various reperfused human cadaver models exist, enabling practise of mainly vascular procedures. Preservation method determines the level of simulation fidelity. Thorough evaluation of these models as surgical training tools and transfer effectiveness is still lacking.

Integrated Otolaryngology and Anesthesia Simulation Model for Crisis Management of Cavernous Carotid Artery Injury

Simulation training is emerging as a cost-effective way to train residents on the skill sets necessary to excel as fully functioning physicians. Until recently, the simulated resident training environments have primarily focused on handling a medical crisis with learners from the same specialty. A dual otolaryngology and anesthesiology simulation was established to improve teamwork and communication skills between specialties. One otolaryngology resident was paired with one anesthesia resident per trial in our study. The multispecialty team addressed three clinical simulation scenarios to manage a cavernous carotid artery-bleeding crisis with an endoscopic endonasal approach. An independent reviewer evaluated each individual based on situation awareness, decision-making, communications and teamwork, as well as leadership. Residents improved on blood loss, pre and post anatomical exam scores, and communication measures through the course of the scenarios. Residents from both specialties rated the simulation highly and wanted further simulation training in the future. Multidisciplinary simulation training is a novel approach for improving communication skills between specialties prior to entering the wards, clinic, or operative arena. The lessons learned from this multidisciplinary simulation transcend the individual experience by allowing trainees to develop algorithms for crisis management and to improve on aspects of teamwork, leadership, and communication skills that can be applied throughout their careers.

Anatomical Region Segmentation for Objective Surgical Skill Assessment with Operating Room Motion Data

Background  Most existing objective surgical motion analysis schemes are limited to structured surgical tasks or recognition of motion patterns for certain categories of surgeries. Analyzing instrument motion data with respect to anatomical structures can break the limit, and an anatomical region segmentation algorithm is required for the analysis. Methods  An atlas was generated by manually segmenting the skull base into nine regions, including left/right anterior/posterior ethmoid sinuses, frontal sinus, left and right maxillary sinuses, nasal airway, and sphenoid sinus. These regions were selected based on anatomical and surgical significance in skull base and sinus surgery. Six features, including left and right eye center, nasofrontal beak, anterior tip of nasal spine, posterior edge of hard palate at midline, and clival body at foramen magnum, were used for alignment. The B-spline deformable registration was adapted to fine tune the registration, and bony boundaries were automatically extracted for final precision improvement. The resultant deformation field was applied to the atlas, and the motion data were clustered according to the deformed atlas. Results  Eight maxillofacial computed tomography scans were used in experiments. One was manually segmented as the atlas. The others were segmented by the proposed method. Motion data were clustered into nine groups for every dataset and outliers were filtered. Conclusions  The proposed algorithm improved the efficiency of motion data clustering and requires limited human interaction in the process. The anatomical region segmentations effectively filtered out the portion of motion data that are out of surgery sites and grouped them according to anatomical similarities.