Fresh Cadaver Model Research Articles

A new concept of transforaminal ventral facetectomy including simultaneous decompression of foraminal and lateral recess stenosis: Technical considerations in a fresh cadaver model and a literature review.

Percutaneous endoscopic surgery for the lumbar spine, which was established in the last decade, requires only an 8-mm skin incision and causes minimal damage to the paravertebral muscles; thus, it is considered to be a minimally invasive technique for spinal surgery. It has been used to perform percutaneous endoscopic discectomy via two main approaches: the TF approach is a posterolateral one through the intervertebral foramen and can be done under local anesthesia; the IL approach is a more traditional one through the interlaminar space and is difficult to perform under local anesthesia. Recently, these techniques have been applied for lumbar spinal stenosis (LSS), the TF method for foraminal stenosis under local anesthesia, and the IL method for central and lateral recess stenosis under general anesthesia. In this study, using a fresh human cadaver model, we performed simultaneous decompression of the lateral recess and foraminal stenosis at L4-5 using the TF approach. Computed tomography confirmed enlargement of the lateral recess and intervertebral foramen. This technique, which can be performed under local anesthesia, should benefit elderly patients with LSS and poor general condition due to multiple comorbidities. Finally, we introduce the concept of percutaneous transforaminal ventral facetectomy using a spinal percutaneous endoscope. J. Med. Invest. 64: 1-6, February, 2017.

Descripción del bloqueo del plexo braquial ecoguiado en espacio costoclavicular mediante abordaje medial y evaluación de la alteración en la perfusión regional secundaria

IntroductionUltrasound-guided infraclavicular block in the costoclavicular space located between the clavicle and the first rib, reaches the secondary trunks when they are clustered together and lateral to the axillary artery. This block is most often performed through a lateral approach, the difficulty being finding the coracoid process an obstacle and guiding the needle towards the vessels and pleura. A medial approach, meaning from inside to outside, will avoid these structures. Traditionally the assessment of a successful block is through motor or sensitive responses but a sympathetic fibre block can also be evaluated measuring the changes in humeral artery blood flow, skin temperature and/or perfusion index. ObjectiveTo describe the medial approach of the ultrasound-guided costoclavicular block evaluating its development by motor and sensitive response and measurement of sympathetic changes. Materials and methodsDescription of the technique and administration of 20ml of contrast in a fresh cadaver model, evaluating the distribution with CT-scan and sagittal sections of the anatomic piece. Subsequently in a clinical phase, including 11 patients, we evaluated the establishment of motor, sensitive and sympathetic blocks. We evaluated the sympathetic changes reflected by humeral artery blood flow, skin temperature and distal perfusion index. ResultsIn the anatomical model the block was conducted without difficulties, showing an adequate periclavicular distribution of the contrast in the CT-scan and in sagittal sections, reaching the interscalenic space as far as the secondary trunks. Successful blocks were observed in 91% of patients after 25minutes. All the parameters reflecting sympathetic block increased significantly. The humeral artery blood flow showed an increase from 108 ± 86 to 188±141ml/min (P=.05), skin temperature from 32.1±2 to 32.8±9°C (P=.03) and perfusion index from 4±3 to 9±5 (P=.003). ConclusionsThe medial approach of the ultrasound-guided costoclavicular block is anatomically feasible, with high clinical effectiveness using 20ml of 1.5% mepivacaine. The sympathetic block can be evaluated with all three parameters studied.

A novel fresh cadaver model for education and assessment of joint aspiration

ObjectivesThe objective of this study was to describe a novel cadaver model and to determine the utility of this model for teaching and assessing students in performing knee, elbow, and wrist arthrocentesis. MethodsThird year medical students were evaluated while performing arthrocentesis during a fresh cadaver training sessions. ResultsSixty-three participants were included in this analysis. There was statistically significant improvement between the pre- and post-test analysis in all aspects assessed in our study of elbow, knee and wrist arthrocentesis. ConclusionsThe use of fresh cadavers for the education and assessment of arthrocenteses is an effective training model.

Development of a fresh cadaver model for instruction of ultrasound-guided breast biopsy during the surgery clerkship: pre-test and post-test results among third-year medical students

BackgroundThe aim of our study was to determine if a fresh cadaver model is a viable method for teaching ultrasound (US)-guided breast biopsy of palpable breast lesions. MethodsThird-year medical students were assessed both preinstruction and postinstruction on their ability to perform US-guided needle aspiration or biopsy of artificially created masses using a 10-item checklist. ResultsForty-one third-year medical students completed the cadaver laboratory as part of the surgery clerkship. Eight items on the checklist were found to be significantly different between pre-testing and post-testing. The mean preinstruction score was 2.4, whereas the mean postinstruction score was 7.10 (P < .001). ConclusionsFresh cadaver models have been widely used in medical education. However, there are few fresh cadaver models that provide instruction on procedures done in the outpatient setting. Our model was found to be an effective method for the instruction of US-guided breast biopsy among medical students.

Introducing a Fresh Cadaver Model for Ultrasound-guided Central Venous Access Training in Undergraduate Medical Education.

IntroductionOver the past decade, medical students have witnessed a decline in the opportunities to perform technical skills during their clinical years. Ultrasound-guided central venous access (USG-CVA) is a critical procedure commonly performed by emergency medicine, anesthesia, and general surgery residents, often during their first month of residency. However, the acquisition of skills required to safely perform this procedure is often deficient upon graduation from medical school. To ameliorate this lack of technical proficiency, ultrasound simulation models have been introduced into undergraduate medical education to train venous access skills. Criticisms of simulation models are the innate lack of realistic tactile qualities, as well as the lack of anatomical variances when compared to living patients. The purpose of our investigation was to design and evaluate a life-like and reproducible training model for USG-CVA using a fresh cadaver.MethodsThis was a cross-sectional study at an urban academic medical center. An 18-point procedural knowledge tool and an 18-point procedural skill evaluation tool were administered during a cadaver lab at the beginning and end of the surgical clerkship. During the fresh cadaver lab, procedure naïve third-year medical students were trained on how to perform ultrasound-guided central venous access of the femoral and internal jugular vessels. Preparation of the fresh cadaver model involved placement of a thin-walled latex tubing in the anatomic location of the femoral and internal jugular vein respectively.ResultsFifty-six third-year medical students participated in this study during their surgical clerkship. The fresh cadaver model provided high quality and lifelike ultrasound images despite numerous cannulation attempts. Technical skill scores improved from an average score of 3 to 12 (p<0.001) and procedural knowledge scores improved from an average score of 4 to 8 (p<0.001).ConclusionThe use of this novel cadaver model prevented extravasation of fluid, maintained ultrasound-imaging quality, and proved to be an effective educational model allowing third-year medical students to improve and maintain their technical skills.

Evaluation of hands-on seminar for reduced port surgery using fresh porcine cadaver model.

BACKGROUND:The use of various biological and non-biological simulators is playing an important role in training modern surgeons with laparoscopic skills. However, there have been few reports of the use of a fresh porcine cadaver model for training in laparoscopic surgical skills. The purpose of this study was to report on a surgical training seminar on reduced port surgery using a fresh cadaver porcine model and to assess its feasibility and efficacy.MATERIALS AND METHODS:The hands-on seminar had 10 fresh porcine cadaver models and two dry boxes. Each table was provided with a unique access port and devices used in reduced port surgery. Each group of 2 surgeons spent 30 min at each station, performing different tasks assisted by the instructor. The questionnaire survey was done immediately after the seminar and 8 months after the seminar.RESULTS:All the tasks were completed as planned. Both instructors and participants were highly satisfied with the seminar. There was a concern about the time allocated for the seminar. In the post-seminar survey, the participants felt that the number of reduced port surgeries performed by them had increased.CONCLUSION:The fresh cadaver porcine model requires no special animal facility and can be used for training in laparoscopic procedures.

Laparoscopic training model using fresh human cadavers without the establishment of penumoperitoneum.

BACKGROUND:Laparoscopy is a well-established alternative to open surgery for treating many diseases. Although laparoscopy has many advantages, it is also associated with disadvantages, such as slow learning curves and prolonged operation time. Fresh frozen cadavers may be an interesting resource for laparoscopic training, and many institutions have access to cadavers. One of the main obstacles for the use of cadavers as a training model is the difficulty in introducing a sufficient pneumoperitoneum to distend the abdominal wall and provide a proper working space. The purpose of this study was to describe a fresh human cadaver model for laparoscopic training without requiring a pneumoperitoneum.MATERIALS AND METHODS AND RESULTS:A fake abdominal wall device was developed to allow for laparoscopic training without requiring a pneumoperitoneum in cadavers. The device consists of a table-mounted retractor, two rail clamps, two independent frame arms, two adjustable handle and rotating features, and two frames of the abdominal wall. A handycam is fixed over a frame arm, positioned and connected through a USB connection to a television and dissector; scissors and other laparoscopic materials are positioned inside trocars. The laparoscopic procedure is thus simulated.CONCLUSION:Cadavers offer a very promising and useful model for laparoscopic training. We developed a fake abdominal wall device that solves the limitation of space when performing surgery on cadavers and removes the need to acquire more costly laparoscopic equipment. This model is easily accessible at institutions in developing countries, making it one of the most promising tools for teaching laparoscopy.

Development of a Fresh Cadaver Model for Instruction of Ultrasound-Guided Breast Biopsy During the Surgery Clerkship: Pre- and Post-Test Results Among Third Year Medical Students

Development of a Fresh Cadaver Model for Instruction of Ultrasound-Guided Breast Biopsy During the Surgery Clerkship: Pre- and Post-Test Results Among Third Year Medical Students

Perception does not equal reality for resident vascular trauma skills

BackgroundExperience with the management of vascular trauma by senior surgical residents is increasingly limited. When queried about their understanding of anatomy and ability to perform specific vascular exposures, residents express a moderately high level of confidence. We hypothesized that this perception does not equal reality. MethodsA total of 42 senior surgical residents participating in an ongoing validation study of the Advanced Surgical Skills for Exposures in Trauma course were asked to self-assess their baseline (precourse) confidence of their understanding of the anatomy required to perform and their ability to perform exposure and control of the axillary, brachial, and femoral arteries, as well as lower extremity fasciotomy using a 5-point Likert scale. Residents then performed the four procedures on a fresh cadaver model and were scored in real time by experts using a global assessment of anatomic knowledge and readiness to perform.” The Student t-test was used with α set at P < 0.05. ResultsResidents consistently rated their understanding of anatomy and their ability to perform the procedures significantly higher than expert evaluator ultimately scored them. Evaluators also deemed that residents would be unable to perform without help 65%–86% of the time. ConclusionsSenior residents are ill-prepared to perform the procedures studied and have an unwarranted confidence in their knowledge and abilities. Perception clearly does not equal reality in preparing these trainees to perform as advertized. The low global scores for anatomy and performance should be a wake-up call for surgical educators prompting curricular reform and evaluation.

Central Venous Catheterization Using a Perfused Human Cadaveric Model: Application to Surgical Education

The purpose of this article is to present a unique training model using a perfused human cadaver for central line placement training with the ultimate goal of reducing central venous catheter mechanical complications. The applicability of the fresh tissue cadaver model for central line placement was assessed using a 10-item questionnaire with a 5-point Likert-type scale. Respondents were asked to rate their opinions as strongly agree, agree, neutral, disagree, or strongly disagree. All participants received a didactic lecture followed by supervised practice on a commercially available simulator. The students were then relocated to the Fresh Tissue Dissection Laboratory where they practiced central vein catheterization on a fresh perfused human cadaver. Course participants included 87 physicians from various medical specialties at different stages of training. Results of the survey demonstrated that 91% of the participating physicians found the perfused cadaveric model to be a true simulation of conditions that exist in live patients, and 98% reported that the use of this model promoted acquisition of technical skills. The integration of central line placement training on perfused cadavers into residency and fellowship training provides an unparalleled realistic simulation to participants. Further study is needed to assess whether realistic simulation translates into objective end points such as decreased mechanical complications.

Smart Trepanation System: Preclinical Analysis of Safety, Efficiency, and User Satisfaction

To reduce the risk of dural tears during craniotomies and the associated complications, we developed the Smart Trepanation System (STS) that provides an image- and sensor-based automatic control of the cutting depth of a manually guided soft tissue preserving saw. This article presents the results of an initial user-centered evaluation. Interactive usability tests with six neurosurgeons were conducted. Resection time and accuracy were recorded in a standardized laboratory setting and compared with a standard craniotome. User satisfaction and subjective workload were assessed using the National Aeronautics and Space Administration Task Load Index scale and a questionnaire regarding intuitiveness, fault tolerance, learnability, and user satisfaction. The mean resection time after getting used to the STS was 36.4 ± 9.2 second longer than with the conventional craniotome. All task load indexes except for the temporal demand were rated higher when using the STS, but all were rated smaller than 3 and thus classified as only a small extra task load. The questionnaire showed that the system is not only feasible but also accepted by surgeons and that the user interaction seems to be designed as intuitive, fault tolerant, and easy to learn. Although the conventional craniotome seems to perform a trepanation faster and with less workload, the advantage of performing a dura-preserving trepanation with significantly smaller cutting gaps outweighs those disadvantages. For validation of those promising in vitro results, further studies have to be conducted in a fresh human cadaver model or in a clinical setting.

Propuesta de metodología docente en vía aérea difícil. Presentación de un modelo interactivo de cadáver fresco congelado

Background and objectiveThe aim of this paper is to present a methodology based on the use of fresh-frozen cadavers for training in the management of the airway, and to evaluate the degree of satisfaction among learning physicians. Material and methodsAbout 6 fresh-frozen cadavers and 14 workstations were prepared where participants were trained in the different skills needed for airway management. The details of preparation of the cadavers are described. The level of satisfaction of the participant was determined using a Likert rating scale of 5 points, at each of the 14 stations, as well as the overall assessment and clinical usefulness of the course. ResultsThe mean overall evaluation of the course and its usefulness was 4.75 and 4.9, out of 5, respectively. All parts of the course were rated above 4 out of 5. The high level of satisfaction of the course remained homogeneous in the 2 editions analysed. The overall satisfaction of the course was not finally and uniquely determined by any of its particular parts. ConclusionThe fresh cadaver model for training physicians in techniques of airway management is a proposal satisfactory to the participant, and with a realism that approaches the live patient.

Targeting accuracy of transcranial magnetic resonance–guided high-intensity focused ultrasound brain therapy: a fresh cadaver model

This work aimed at evaluating the accuracy of MR-guided high-intensity focused ultrasound (MRgHIFU) brain therapy in human cadaver heads. Eighteen heads of fresh human cadavers were removed with a dedicated protocol preventing intracerebral air penetration. The MR images allowed determination of the ultrasonic target: a part of the thalamic nucleus ventralis intermedius implicated in essential tremor. Osseous aberrations were corrected with simulation-based time reversal by using CT data from the heads. The ultrasonic session was performed with a 512-element phased-array transducer system operating at 1 MHz under stereotactic conditions with thermometric real-time MR monitoring performed using a 1.5-T imager. Dissection, imaging, targeting, and planning have validated the feasibility of this human cadaver model. The average temperature elevation measured by proton resonance frequency shift was 7.9°C ± 3°C. Based on MRI data, the accuracy of MRgHIFU is 0.4 ± 1 mm along the right/left axis, 0.7 ± 1.2 mm along the dorsal/ventral axis, and 0.5 ± 2.4 mm in the rostral/caudal axis. Despite its limits (temperature, vascularization), the human cadaver model is effective for studying the accuracy of MRgHIFU brain therapy. With the 1-MHz system investigated here, there is millimetric accuracy.

Pulmonary aspiration associated with supraglottic airways: Proseal laryngeal mask airway and I-Gel™

Pulmonary aspiration associated with supraglottic airways: Proseal laryngeal mask airway and I-Gel™

Simulation in surgery: a review

The ability to acquire surgical skills requires consistent practice, and evidence suggests that many of these technical skills can be learnt away from the operating theatre. The aim of this review article is to discuss the importance of surgical simulation today and its various types, exploring the effectiveness of simulation in the clinical setting and its challenges for the future. Surgical simulation offers the opportunity for trainees to practise their surgical skills prior to entering the operating theatre, allowing detailed feedback and objective assessment of their performance. This enables better patient safety and standards of care. Surgical simulators can be divided into organic or inorganic simulators. Organic simulators, consisting of live animal and fresh human cadaver models, are considered to be of high-fidelity. Inorganic simulators comprise virtual reality simulators and synthetic bench models. Current evidence suggests that skills acquired through training with simulators, positively transfers to the clinical setting and improves operative outcome. The major challenge for the future revolves around understanding the value of this new technology and developing an educational curriculum that can incorporate surgical simulators.

Airway scope vs Macintosh laryngoscope during chest compressions on a fresh cadaver model

Purposes This study compared the Airway scope (AWS) to the Macintosh laryngoscope (ML) during chest compressions on a fresh cadaver. Methods This was a prospective crossover study. The participants who had experiences with AWS were excluded. The participants intubated with randomly assigned AWS or ML on a fresh cadaver during chest compressions. Primary outcome were as follows: time to intubation, ease of intubation (rated by using the visual analog scale [VAS]), and intubation success rate. Results Twenty-five were enrolled. Median time of intubation was similar between the AWS and ML (AWS, 18.5 seconds vs ML, 18.3 seconds; P = .112). The median VAS of AWS and ML were 3.0 and 2.0, respectively ( P = .023). There was no failure of intubation. However, participants replied that the AWS was more difficult to use than the ML. Conclusion Considering the lack of experience with the AWS, AWS could be an alternative intubation device during chest compressions after practices with AWS.

Anatomy and Vascularization of the Flexor Hallucis Longus Muscle and Its Implication in Free Fibula Flap Transfer

Contracture as well as weakness of the flexor hallucis longus (FHL) are possible complications following free fibula flap harvest. Possible causes have been related to fibrotic change of the muscle either due to devascularization or compartment-like syndrome after a tight wound closure. This study elucidates the vascularization and nerve supply of the FHL muscle after fibula flap harvest in a fresh cadaver model.A fibula bone flap was harvested through a lateral approach in 20 fresh limbs. The popliteal artery was isolated and injected with a silicone compound, the muscle isolated, and its neurovascular supply visualized.The distal third and fourth portion of the FHL muscle was always found to be located in a more compressed and deeper compartment. The peroneal artery was entirely filled by the silicone compound in 17 fresh cadaver limbs with at least one branch supplying the distal fourth of the FHL. The posterior tibialis artery was filled in all limbs and an average of 2 branches was found to supply the muscle. In all dissections, the nerve supplying the FHL originated from the tibialis nerve with an average of three branches perforating the muscle.Following fibula harvest, the FHL muscle will maintain vascular supply through the distal portion of the peroneal artery and the posterior tibialis artery. Nerve injury to the FHL muscle is unlikely during flap harvest.

Retroperitoneal robotic renal surgery: technique and early results.

We describe a robotic retroperitoneal approach to renal surgery, optimized in porcine and cadaveric models, and applied to human patients. A retroperitoneal approach for robotic kidney surgery was developed in nonsurvival porcine and a fresh cadaver models, and then utilized in ten patients (three partial nephrectomy, three radical nephrectomy, two simple nephrectomy, one pyeloplasty, one cryoablation). Retroperitoneal access was successfully achieved for robotic renal procedures in six pigs and a human cadaver. Ten human patients (mean age 56years, range 36-72years) then underwent a successful retroperitoneal approach for robotic renal surgery. Mean console time was 166(120-300)min. Mean blood loss was 82(50-100)ml and average hospital stay was 2.6(1-5)days. Pathology demonstrated clear cell renal cell carcinoma (four), papillary renal cell carcinoma (two), and xanthogranulomatous pyelonephritis (two). One patient with xanthogranulomatous pyelonephritis required open conversion for failure to progress due to dense adhesions. A retroperitoneal approach is a safe and feasible alternative to a transperitoneal approach for robotic renal surgery, including radical nephrectomy, partial nephrectomy, pyeloplasty, and cryoablation.

Technical and Anatomical Considerations of Face Harvest in Face Transplantation

Total face transplantation may become a reconstructive option in the treatment of patients with acquired facial deformity. Here, 2 face-harvesting techniques are presented in a fresh human cadaver model. In technique 1, the skin and soft tissue of the face is harvested by dissecting in a subgaleal, sub-SMAS, subplatysmal plane. In technique 2, the entire soft tissue and the bony structures of the midface are harvested by dissecting in a subperiosteal plane and performing a Le Fort III osteotomy. Each face was harvested successfully as a bipedicled flap based on the external carotid arteries, the external jugular veins, and the facial veins. Each of these 2 techniques is a theoretically viable approach to face harvest for composite allograft transplantation. These techniques represent the 2 extremes of which tissues can be harvested while maintaining vascular integrity. Each will address different reconstructive needs.

Training Fourth-Year Medical Students in Critical Invasive Skills Improves Subsequent Patient Safety

Complications after procedures performed by residents are thought to occur most often early in the first postgraduate year (PGY-1). We evaluated the number of pneumothoraces (PTXs) caused by central venous line insertion (CVLI) by two groups of PGY-1 residents in both the first 3 months of residency and the entire year from 1996 through 2000 to determine the impact of CVLI training on PTX. From 1996 through 1998 fourth-year medical students had no specific training in CVLI and learned on the job as residents. Starting with the Class of 1999 we replaced this approach with a structured program in CVLI. Didactic sessions detailing anatomy and technique were followed by skill performance in a fresh cadaver model. Students performed skills initially under the direct supervision of a faculty member, who provided immediate feedback. Videotapes of this performance were reviewed with the students by both surgeons and kinesiologists to correct deficits before repeat sessions. Skills were repeated until competence was attained. Graduating students have made up greater than 90 per cent of our two hospitals' PGY-1 residents since 1996. Because these residents are responsible for CVLI we are able to obtain performance follow-up in actual clinical settings. We obtained the number of PTXs caused by CVLI for the years 1996 through 2000 as well as for the first 3 months of each academic year (July through September) to determine the impact of our program on this serious complication. The number of PTXs during the first 3 months of 1996-1998 remained stable. After the introduction of our teaching program the number decreased significantly in the years 1999-2000 when compared with 1996-1998 (P = 0.004, t test). The overall yearly decrease for 1999 versus 1996-1998 approached significance (P = 0.06). The introduction of a structured teaching program of CVLI skills appears to have a positive impact in reducing morbidity of PTX. The greatest impact occurs within the first 3 months of the new PGY-1 academic year.