Thiel's Method Research Articles

A Comparative Study of Thiel Soft-embalmed and Formalin Preserved Cadavers for Anatomy Dissection

Background and Objective. Cadavers are the main teaching and learning tools utilized by faculty and students of Gross Anatomy. The conventional procedure of using formalin to preserve cadavers has its limited benefit due to its obnoxious odor, darkened color, indistinguishable small structures, rigid joints, with friable organs and tissues. Using the Thiel Method, cadavers are known to have: life-like presentation, a high degree of suppleness, natural mobilization of various body parts with tolerable odor, natural color, and antimicrobial and antifungal efficacy. The aim of this study was to compare the Thiel soft-embalmed cadaver and the formalin-preserved cadaver for use in Gross Anatomy dissection.
 Materials and Method. Six formalin-preserved cadavers were compared with six Thiel soft-embalmed ones and were evaluated by 160 first year medical students and 10 faculty members of Gross Anatomy from the University of the Philippines College of Medicine using a visual analogue scale that evaluated the cadaver’s presenting color. A Likert scale was utilized to assess the skin and muscle texture, blood vessel integrity, odor, joint flexibility, and state of cadaver preservation. Their perceptions on the ease of the dissection process, distensibility, and differentiation of structures were also elicited through a questionnaire checklist.
 Results. Results show that the Thiel Method-preserved cadavers were rated higher compared to the formalinpreserved cadavers in terms of: 1) presenting color; 2) tolerable odor; 3) skin and muscle texture; 4) blood vessel integrity; 5) joint flexibility; and 6) state of cadaver preservation after 1 year. However, the ease of the dissection process, the distensibility of structures, and the differentiation of the various structures were easily managed in the formalin-preserved cadavers while the feasibility of practicing laparoscopy, endoscopy, and intubation were seen in the Thiel soft-embalmed cadavers. Results validate the claims of previous studies on the advantages presented in using the Thiel Method.
 Conclusion. Cadavers preserved utilizing the Thiel Method are life-like and can be used for Gross Anatomy dissection. The data gathered support the feasibility of using them also in research and training.

Bone block augmentation from the iliac crest for treatment of deep osteochondral defects of the knee resembles biomechanical properties of the subchondral bone.

Bone block augmentation from the iliac crest can be used for reconstruction of the osteochondral unit to restore the underlying subchondral bone upon restoration of the cartilaginous layer via matrix-induced chondrocyte transplantation. To critically understand the successful restoration of the defect, biomechanical and histological analysis of the implanted bone blocks is required. The aim of the study was to analyse the ability of the bone block technique to restore huge bone defects by mimicking the physiological subchondral zone. The experiments were performed using lateral femoral condyles and iliac crest bone grafts from the same cadavers (n = 6) preserved using the Thiel method. CT scans were made to evaluate bone pathology. Bone mineral density of all specimens was evaluated in the femoral head prior to testing. A series of tests were conducted for each pair of specimens. A static compression test was performed using an electro dynamic testing machine with maximal strength and failure behavior analyzed. Biomechanical tests were performed in the medial-lateral direction for iliac crest and for femoral condyles with and without removal of the cartilage layer. Histological analysis was performed on decalcified specimens for comparison of the condyle at lesion site and the graft. No significant difference in failure load could be found for iliac crest (53.3-180.5N) and femoral condyle samples upon cartilage removal (38.5-175.1N) (n.s.). The femoral condyles with an intact cartilage layer showed significantly higher loads (118.3-260.4N) compared to the other groups indicating that native or regenerated cartilage can further increase the failure load (p < 0.05). Bone mineral density significantly influenced failure load in all study groups (p < 0.05). Histological similarity of the cancellous bone in the femoral condyle and in the iliac crest was observed. However, within the subchondral zone, there was a higher density of sponge like organized trabeculae in the bone samples from the iliac crest. Tide mark was only detected at the osteochondral interface in femoral condyles. This study demonstrated that, bone blocks derived from the iliac crest allow a biomechanical appropriate and stable restoration of huge bony defects by resembling the subchondral zone of the femoral condyle. Therefore, bone augmentation from the iliac crest combined with matrix-induced autologous chondrocyte transplantation seems to be a reasonable method to treat these challenging injuries.

Reproducibility of navigation based kinematic analysis of the knee – A cadaveric investigation

PurposeSeveral navigation-based kinematic studies of the knee have been published recently, but little information is available about reproducibility and reliability of the acquired data. The aim of the present study first is to determine reproducibility and reliability of kinematical measurements of healthy knees and knees after TKA (total knee arthroplasty) with regards to rotational and translational measurement parameters. Second the mathematical background, applicability, and limitations of investigating navigation-based kinematics should be compiled. MethodsUsing cadavers fixed by the Thiel method, in ten knees reproducibility of obtained angular and translational kinematic parameters were investigated before and after total knee arthroplasty. For this reason agreement of obtained data of a first and a second movement cycle and the same after a surgical intervention was assessed using a commercially available navigational device. ResultsFor both angular and translational parameters in healthy knees and knees after total knee arthroplasty mean differences between measured parameters of the first and second movement cycle and after surgical intervention of less than 0.5° or millimeters (standard deviation 1.3 or less) or a inter class correlation of 0.92 and more, respectively, was found. DiscussionUse of a commercial navigation system allows highly accurate investigations of knee kinematics in cadavers before and after TKA. This technique, which does not require any specific technical knowledge of the investigator, is in accordance with current accepted biomechanical methods.

Kinematic component alignment in total knee arthroplasty leads to better restoration of natural tibiofemoral kinematics compared to mechanic alignment.

Kinematically aligned total knee arthroplasty is associated with superior pain relief, increased flexion and a more normal feeling knee. It was hypothesized that due to restoring the knee's natural anatomy, kinematically aligned knees show more physiological tibiofemoral kinematics than mechanically aligned knees. Investigations were performed in nine healthy cadaveric knees of whole bodies fixed by the Thiel method. Tibiofemoral kinematics of healthy knees and after kinematically and mechanically aligned total knee arthroplasty were assessed between 0° and 90° of flexion by a navigational device. Regarding tibial internal rotation or femoral roll back, respectively, kinematically aligned total knee arthroplasties showed no significant differences between 0° and 70° of flexion in comparison to knees before total knee arthroplasty. In contrast, mechanically aligned total knee arthroplasties showed significant changes between 10° and 90° of flexion. Kinematically aligned knees showed a significant changed abduction/adduction between 20° and 70° of flexion, mechanically aligned knees within 20° and 90° of flexion. In the present study setting kinematically aligned total knee arthroplasties showed more natural and physiological tibiofemoral kinematic pattern with regard to tibial internal rotation or femoral rollback, respectively, and tibial adduction than mechanically aligned total knee arthroplasties. While these results may support promising early clinical results of kinematical alignment proposing a better function, long-term results especially implant survival need to be awaited.

The right intercostobronchial trunk: anatomical study in respect of posterior intercostal artery origin and its clinical application.

The right bronchial artery usually arises from the descending thoracic aorta as a common trunk with the right intercostal artery and forms the right intercostobronchial trunk. Both, the third right posterior intercostal artery and the right intercostobronchial trunk, are described as the most constant vessels. The focus of the study was to determine the characteristics of the right intercostobronchial trunk regarding the origins of the posterior intercostal arteries from the thoracic aorta. Posterior intercostal arteries and the right bronchial arteries were dissected in 43 human cadavers, preserved after Thiel's embalming method with intraarterial infusion of red colored latex. Postmortem examination gave valued information on the right intercostobronchial trunk present in 58% of cases. The right intercostobronchial trunk was mapped and new classification regarding the origin of the posterior intercostal arteries from the thoracic aorta suggested type A, B and C, the latter ones into subtypes 1 and 2. Type A was proportional to the origin level of the PIA and its corresponding intercostal space. Size of outer diameter at the origin did not indicate the right bronchial artery branch. In subtype 2 of type B the proximal posterior intercostal artery diameter that gave off right bronchial artery was thicker than distal one. The right bronchial artery originates from the second to the fifth posterior intercostal artery forming the right intercostobronchial trunk. Various origin and types of origin, diameter and course of the right intercostobronchial trunk described and analyzed in the study offer valuable information on the procedures involving the right intercostobronchial trunk.

Human cadavers preserved using Thiel's method for the teaching of fibreoptically‐guided intubation of the trachea: a laboratory investigation

We assessed the suitability of human cadavers preserved using Thiel's method for teaching flexible fibreoptic tracheal intubation. Thirty-one anaesthetists unacquainted with this technique received didactic teaching followed by handling of the fibrescope on the Oxford teaching box. They then carried out fibreoptic intubations in two cadavers to establish a baseline sample of their intubation skills. Thereafter, we randomly assigned the trainees to two groups to practice fibreoptic intubation either on two distinct cadavers or on two airway manikins. After 7days we re-assessed procedural skills using the same cadavers as at baseline. Intubation time was the primary outcome and secondary outcomes included the incidence of failed intubations. We also evaluated trainee satisfaction. The mean (SD) intubation time decreased from a baseline value of 74 (20)s to 35(6)s in the cadaver group and to 56 (16)s in the manikin group. The effect of 'time' was significant (p=0.002), indicating that both methods of training led to improvements. The training effect of the cadaveric method was greater than with the manikin method (p=0.0016). Thirty-four failed intubations occurred at baseline vs. eight at the end of study (RR 0.24, 95%CI 0.11-0.51, p=0.0002, NNT 9.6); six in the cadaver group and two in the manikin group (p=0.22). We conclude that human cadavers preserved using Thiel's method are potentially better for teaching flexible fibreoptic tracheal intubation compared with manikins.

Mechanical characteristics of the maxillary sinus Schneiderian membrane ex vivo.

It has been speculated that certain Schneiderian membrane thickness (SMT) might be more prone to perforation. This investigation was aimed at studying the mechanical characteristics of the Schneiderian membrane under one- and two-dimensional tests and their correlation to the histological SMT in human samples. Sixteen Schneiderian membranes were collected from 11 cadaver heads treated with Thiel's embalming method. The samples were processed and analyzed clinically and histologically. One-dimensional maximum elongation until perforation and two-dimensional resistance to ball penetration were performed after the biopsy. Data was analyzed by using the Wilcoxon rank test and the Spearman's rank correlation. The histological SMT was 1.36±0.42mm, whereas the clinical thickness was 0.27±0.21mm, yielding statistical significance (p=0.000). The resistance under ball penetration was 0.59±0.43N and the mean maximum elongation in the one-dimension test 11.19±7.14mm. Expressed in percentage, the mean stretch was 241.36±227.97% (range 31.5 up to 947%). A weak positive correlation was found between the ball penetration test and the SMT (r=0.10, p=0.711), while a weak negative correlation was found between stretching test and the SMT (r=-0.021, p=0.94). Mechanical tests seem to indicate that SMT might not significantly predispose to Schneiderian membrane perforation. Hence, other anatomical and operator's factors should be considered of surpassing importance. Thinner SM might be more prone to perforation when detaching it from the maxillary sinus antrum; however, a thick membrane is not prevented to tear, as their resistance under elastic forces is not higher than thinner ones.

Ureterorenoscopy training on cadavers embalmed by Thiel's method: simulation or a further step towards reality? Initial report.

IntroductionThe technique of ureterorenoscopy has a significant learning curve. Cadavers embalmed by the Thiel method have been successfully used for simulation training in a number of surgical specialties. Here we present our experience of the first use of Thiel cadavers in a formal ureteroscopy training course.Material and methodsThe inaugural ‘Masterclass in Flexible Ureterorenoscopy’ was run with participants performing ureterorenoscopy on three Thiel cadavers under expert supervision. A qualitative questionnaire was delivered to the participants and faculty. Assessed domains were tissue characteristics of the cadaveric urinary tract, anatomical features and procedural aspects. A five-point Likert score was used to assess responses. Data regarding participant experience in endourology were also collected.Results8 questionnaires were collected. All participants completed cadaveric ureterorenoscopy. Three-quarters reported the overall quality of tissue in the cadaveric bladder, ureters and pelvicalyceal system as high or excellent. Half reported the cadaveric bladder as being softer than in a live patient, whilst five out of eight thought that the cadaveric ureter was softer and more prone to trauma. Seven out of eight were satisfied with the overall quality of the cadaveric model. The quality of vision and irrigation in the upper urinary tracts was reported as high.ConclusionsThiel cadavers have been shown to have excellent tissue characteristics, as well as being durable and reusable. We have described the first use of Thiel cadavers in a designated ureterorenoscopy course, with high levels of delegate satisfaction. Further work is required to develop the role of Thiel cadavers as part of an integrated, modular urology training.

The feasibility of micro-ultrasound as a tool to image peripheral nerves.

Despite widespread use of ultrasound imaging to guide needle placement, the incidence of transient and permanent nerve damage as a complication of regional anaesthesia has not changed over the last decade. In view of the controversy surrounding intraneural injection there is a need to understand the structural changes caused by subepineural and subperineural needle penetration. Clinical ultrasound machines do not provide adequate anatomical resolution, and anaesthetists have difficulty judging the precise location of the needle tip relative to the epineurium. We studied the suitability of micro-ultrasound imaging (which offers anatomical resolution better than 100 μm) as a tool for viewing neural anatomy and deformation caused by needle insertion. The primary objective was to assess micro-ultrasound imaging as a method to view fascicles within nerves resected from fresh and soft-embalmed cadavers. Secondary objectives were to observe any disruption of the neural anatomy caused by anaesthetic needle penetration, and to assess the integrity of fresh and Thiel method soft-embalmed nerves, after handling and during needle insertion using ultrasound images and histology. We imaged nine nerves from the left and right sides of fresh and soft-embalmed cadavers. A regional block needle was inserted into three median nerves. We identified fascicles > 0.4 mm in width using micro-ultrasound. Subepineural needle placement was associated with denting, rotation and elastic deformation of fascicles, whereas subperineural needle insertion split fascicles permanently.

Wrist denervation of the posterior interosseous nerve through a volar approach: a new technique with anatomical considerations.

Full or selective wrist denervation is an effective treatment for chronic wrist pain. In this cadaveric study, a volar approach for prophylactic denervation of the posterior interosseous nerve (PIN) and the anterior interosseous nerve (AIN) was assessed, which can simultaneously be performed during volar approaches for distal radius fracture fixation or in combination with metalwork removal. In total 40 adult upper limbs, embalmed using Thiel's method, were investigated. Group 1 included 20 limbs of which the distances between AIN and PIN to the ulnar margin of radius were measured at levels 6, 8 and 10cm proximal to the styloid process and the distance radial styloid process to proximal border of pronator quadratus which might be useful as an intraoperative landmark. Subsequently further additional 20 adult limbs (group 2) were used. Transection of the PIN via this volar approach at the evaluated best level of step 1 was performed and evaluated by dissection via a dorsal approach. In group 1, the PIN runs within the interosseous membrane, from the ulnar border of the radius, 6.4mm (SD 2.66) at 6cm, 8.4mm (SD 2.28) at 8cm and 3.75mm (SD 5.46) at 10cm proximal to the radial styloid. The AIN runs within the interosseous membrane, from the ulna edge of the radius, 7.5mm (SD 2.4) at 6cm, 7.3mm (SD 1.95) at 8cm and 2.35mm (3.42) at 10cm proximal to the radial styloid. AIN and PIN were in close proximity at the 8-cm level which equals a 1-cm distance proximal to the pronator quadratus border. Group 2 showed a successful transection of the PIN through a single volar surgical approach in additional 18 out of 20 adult upper limbs. This study shows the local anatomy of the PIN, allowing denervation via a volar approach.

The fascial suspension of the prostate: A cadaveric study.

Analysis and description of the supporting fascial structure around the prostate and urethra, which needs to be preserved or restored during radical prostatectomy (RP). Anatomical dissection of 10 male cadavers was performed and the supporting fascial structures of bladder neck, prostate, and proximal urethra were investigated. The cadavers were embalmed according to Thiel's method, which preserves a natural texture and color of tissues. Anteriorly, the puboprostatic ligament (PL), the dorsal vein complex, and the urethropelvic ligament form an integral structure that suspends and stabilizes the prostatic apex. Laterally, the fascia originates from the fascial tendinous arch of the pelvis and stabilizes the prostate in the central position. In the posterolateral aspect, we could demonstrate a tendineous dorsal raphe, which represents an important stabilization structure of the urethra. The anterior and posterior pelvic fascial structure seems to be important stabilizer for the prostate and proximal urethra. Their preservation or reconstruction during RP is mandatory to restore the anatomic and functional continuity of the bladder neck and urethra. Neurourol. Urodynam. 36:1131-1135, 2017. © 2016 Wiley Periodicals, Inc.

Thermocoagulation of the Medial Branch of the Dorsal Branch of the Lumbal Spinal Nerve: Flouroscopy Versus CT.

For radiofrequency neurotomy of the medial branch of the lumbar dorsal rami, physicians use techniques guided either by fluoroscopy or computerized tomography (CT), and advocate for their respective techniques. Crucial to the choice of technique is how well each can capture the target nerve. The present study was, therefore, undertaken to assess in cadavers the accuracy of fluoroscopic-guided and CT-guided techniques. In10 cadavers preserved with Thiel's method, electrodes with 10mm active tips were placed in supine position on the right using a fluoroscopic-guided technique, and on the left using a CT-guided technique. Using a special dissection approach, the relationship between the target nerve and the tip of the electrode was revealed. The displacement between electrode and the nerve, and the extent to which the electrode was parallel to the nerve, were measured with callipers. Under fluoroscopy guidance, electrodes were placed accurately beside the nerve, and were parallel to it for 9 ±1.9 mm. In only two cases did the electrode pass too deeply. Under CT guidance, electrodes often failed to reach the nerve, but when they did they were parallel to it for only 3.2 ± 3.2 mm. In seven cases, the electrode passed too deeply beyond the target nerve. The fluoroscopy-guided technique can be relied upon to achieve optimal placement of electrodes on the lumbar medial branches. The CT-guided technique fails to do so, and should not be used in practice until a modified version has been developed and validated.

Ureterorenoscopy Training on Cadavers Embalmed by Thiel's Method: Simulation or a Further Step Towards Reality? Initial Report

Ureterorenoscopy Training on Cadavers Embalmed by Thiel's Method: Simulation or a Further Step Towards Reality? Initial Report

Experience of Raising Flaps Using Cadavers Embalmed by Saturated Salt Solution Method

Sir: In plastic and reconstructive surgery, raising the flap is an important skill1; but sometimes it is difficult for young plastic surgeons to detect and isolate the vessels. However, only a few studies have focused on flap training using cadavers. In these studies, researchers used formalin fixation techniques, which produced tissues with rigidities too high to provide a realistic simulation of flap training.2 Therefore, preservation methods such as fresh cadaver3,4 and Thiel method2 have been favored. Fresh cadaveric tissue is a superior model of simulation because of its approximation of live tissue,4 but it has many disadvantages such as high cost, limited use, and risk of infection.1,2 Thiel-embalmed cadavers have life-like color and flexibility.2 However, Thiel method is quite complicated and requires the use of several problematic and expensive substances during its preservation process. In addition, Thiel-embalmed cadavers have their drawbacks: muscular disintegration and limited time for dissection.5 Recently, Hayashi et al5 reported that the cadavers embalmed by the saturated salt solution (SSS) method, which consisted of saturated sodium chloride, low-dose formaldehyde, phenol, glycerin, isopropyl alcohol, and water, were not less suitable than Thiel-embalmed cadavers in several skills training courses in acute care surgery. Therefore, the authors tried raising several flaps in the SSS-cadavers for future use in flap training. Four SSS-embalmed cadavers and 1 Thiel-embalmed cadaver were used for this study, and the procedures were performed in an anatomical training room at Tokyo Medical University. All procedures were performed by Takayuki Shirai (a plastic surgeon with 9 years of experience). The cadavers were used 1–6 months after they had been preserved, and each cadaver was used several times. The types of flaps made included the following: oblique triangular flap, reverse digital artery island flap (Fig. 1), latissimus dorsi musculocutaneous flap, superficial temporal fascia flap, nasolabial flap, and anterolateral thigh flap (Fig. 2).Fig. 1: Reverse digital artery island flap.Fig. 2: Anterolateral thigh flap.Because SSS-embalmed cadavers tend to have realistic skin and soft tissue, anatomical structures were easy to identify and the operations could be performed very much as in live patients (Figs. 1, 2). These features of SSS-embalmed cadavers were almost identical to those in Thiel-embalmed cadavers. In addition, the vessels of the SSS-embalmed cadavers were more expanded because of ample fluid, making our detection and isolation of vessels and raising of flaps easier in them than in the Thiel-embalmed cadaver. CONCLUSIONS SSS-embalmed cadavers are sufficiently useful in flap training. The SSS method is simple with a low infection risk and relatively low cost.5 Furthermore, SSS-embalmed cadavers have availability for multiple uses and their vessels can be easily detected. Our trial suggests that the characteristics of SSS-embalmed cadaver may be ideal for trainees of plastic surgery. ACKNOWLEDGMENTS We thank Dr. Ning Qu, Dr. Naoyuki Hatayama, and Dr. Shuichi Hirai for reviewing and providing useful comments to us preparing in our manuscript. We also thank Mr. Shinichi Kawata and Mr. Koichi Koyama for their excellent technical assistance, and Ms. Yuki Ogawa, Ms. Miyuki Kuramasu, and Ms. Keiko Kuwana for their excellent secretarial assistance. DISCLOSURE The authors have no financial interest to declare in relation to the content of this article. This study was supported by JSPS KAKENHI Grant Number 26463257. The Article Processing Charge was paid for by the authors. Takayuki Shirai, MD Department of Plastic Surgery Asama General Hospital Saku-shi, Nagano, Japan Department of Anatomy Tokyo Medical University Shinjuku-ku, Tokyo, Japan Shogo Hayashi, MD, PhD Masahiro Itoh, MD, PhD Department of Anatomy Tokyo Medical University Shinjuku-ku, Tokyo, Japan

Minimally invasive approach to the radial nerve – A new technique

To describe a minimally invasive approach to find the radial nerve (RN) simply and safely by tracing the posterior antebrachial cutaneous nerve (PACN) without damaging muscles, using only the surgeon's hand to define a window for the skin incision. Although it is absolutely necessary to locate the radial nerve during osteosynthesis of the humerus, the literature lacks guidelines on how to do so. We have dissected the upper extremities of 54 adult human cadavers, embalmed using Thiel's method. After the PACN was identified in a defined space, its course was traced proximally by incising the lateral intermuscular septum (LIS) of the upper arm and thereby reaching the radial nerve (RN). Subsequently, using the lateral epicondyle (LE) of the humerus as a reference point, the distances to the points where the PACN perforated the LIS, and where the RN was identified, were measured. These individual data were related to the total length of the humerus. The results indicate that with this approach and without harming musculature, the RN can be reached by tracing the PACN at a height of 11.1-13.0 cm (females) and 11.9-14.0 cm (males) starting from the LE. Our examination shows the PACN to be a convenient guide to the RN.

History and future of human cadaver preservation for surgical training: from formalin to saturated salt solution method.

Traditionally, surgical training meant on-the-job training with live patients in an operating room. However, due to advancing surgical techniques, such as minimally invasive surgery, and increasing safety demands during procedures, human cadavers have been used for surgical training. When considering the use of human cadavers for surgical training, one of the most important factors is their preservation. In this review, we summarize four preservation methods: fresh-frozen cadaver, formalin, Thiel's, and saturated salt solution methods. Fresh-frozen cadaver is currently the model that is closest to reality, but it also presents myriad problems, including the requirement of freezers for storage, limited work time because of rapid putrefaction, and risk of infection. Formalin is still used ubiquitously due to its low cost and wide availability, but it is not ideal because formaldehyde has an adverse health effect and formalin-embalmed cadavers do not exhibit many of the qualities of living organs. Thiel's method results in soft and flexible cadavers with almost natural colors, and Thiel-embalmed cadavers have been appraised widely in various medical disciplines. However, Thiel's method is relatively expensive and technically complicated. In addition, Thiel-embalmed cadavers have a limited dissection time. The saturated salt solution method is simple, carries a low risk of infection, and is relatively low cost. Although more research is needed, this method seems to be sufficiently useful for surgical training and has noteworthy features that expand the capability of clinical training. The saturated salt solution method will contribute to a wider use of cadavers for surgical training.

An Experimental Model for Training in Renal Transplantation Surgery With Human Cadavers Preserved Using W. Thiel’s Embalming Technique

To describe a novel cadaver-based model for practicing renal transplant (RT) surgery. A simulating model using cadavers preserved by Thiel's method is developed to teach surgical anatomy and operative skills in RT surgery. Participants were asked to complete a voluntary, anonymous survey evaluating perceptions of the model and comparing cadaver sessions to other types of learning (rating questions from 0-10). Large university teaching hospital. A total of 28 residents, junior transplant surgeons, and faculty members were participants in the cadaver simulation. Overall, 9 cadavers were used with 17 grafts transplanted. Kidney procurement in human cadavers preserved using Thiel's embalming technique was performed following the conventional protocol; en bloc nephrectomy with the trunk of aorta and inferior vena cava. Bench surgery was performed, perfusing artery with saline and checking vascular permeability. Once suitability is established, RT was performed as is done in clinical practice. This embalming method enables tissue dissection that is comparable to the living body and provides suitable conditions for realistic RT simulation; handling human tissues and vessels in the same surgical field as the clinical scenario. This experimental model approximates to in vivo RT, providing a realistic and interesting learning to inexperienced surgeons. Overall, participants held a positive view of the cadaver sessions, believed them to be useful in their daily practice, and felt that the proposed model was similar to the clinical setting. Trainees believed that these practices improved skills and confidence in performing an RT. The proposed method of kidney procurement and RT in human cadavers preserved by Thiel's embalming technique is a promising, realistic, and reproducible method of practicing RT surgery.

Board #157 - Research Abstract Transitioning from FLS Penrose Drains to Human Cadaver Tissue

Hypothesis Recently, Britt et al. measured the difference in mental workload when transitioning from the FLS system to fresh cadavers.1 They trained their participants to proficiency2 for intracorporeal suturing on the rubber FLS Penrose drains and observed substantial increases in suturing times and subjective workload when the participants attempted to suture bowel tissue. There are many reasons why mental workload would be higher for the cadaver over the FLS simulator. Our goal was to address one possibility: perceived differences in the properties of the rubber drain and cadaver bowel tissue. We hypothesized that differences in the stiffness and elasticity of human bowel tissue and the rubber drains contribute to the increased mental workload. To explore this idea, we used the psychophysical scaling method of magnitude estimation.3-4 Participants assigned comparative numerical values to the properties of the bowel tissue to identify potential perceived differences between the two media. Methods Eight surgical assistants (SA) participated in this IRB approved study. They were trained to proficiency in intracorporeal suturing on the FLS system. They practiced suturing on the FLS Penrose drains for 30 minutes and then performed three sutures in the bowel of a fresh cadaver using Stryker high definition endoscopic towers and Stryker 10 mm 30 degree scopes. The fresh cadavers were soft embalmed using the Modified Thiel method with nitrate salts to maintain tissue flexibility and allow insufflation. The participants used the magnitude estimation procedure and provided estimates for stiffness and elasticity. They were told to consider the Penrose drain as the standard with a value of 100 and to provide numerical estimates of the perceived differences in sensation of the bowel tissue (e.g., if the bowel tissue felt half as stiff as the drain they should give it the number 50). Results Data from five of SA students were available for analysis. The magnitude estimates were analyzed with one sample t tests as deviations from the standard. The perceived elasticity increased from 100 to 174 (SD = 25), t(4) = 6.59, p < .003, Cohen’s D = .86. Regarding stiffness, the reported values decreased from 100 to 81 (SD = 40.1) which was not significant, p > .05. However, all but one participant reported a decrease in stiffness. With that participant removed, the decrease in stiffness dropped from 100 to 71 (SD = 21.3), t(3) = 4.53, p < .02, Cohen’s D = .81. Conclusion The results show that participants did indeed perceive differences between the human bowel tissue and the rubber Penrose drains. Specifically, they rated the elasticity of the human bowel nearly two times greater than that of the rubber drain. The bowel tissue was rated slightly less stiff than the rubber drain. Although the estimates were obtained with a small sample the Cohen’s D values for both properties were quite large indicating a large effect. These results suggest that differences in properties of the cadaver tissue and the rubber drain are clearly perceivable and may contribute to the increased workload observed by Britt et al.1 when trainees transition from FLS to a more realistic surgical environment.

A new beating-heart off-pump coronary artery bypass grafting training model

Training models are essential in mastering the skills required for off-pump coronary artery bypass grafting (OPCAB). We describe a new, high-fidelity, effective and reproducible beating-heart OPCAB training model in human cadavers. Human cadavers were embalmed according to the 'Thiel method' which allows their long-term and repeated use. The training model was constructed by bilateral ligation of the pulmonary veins, cross-clamping of the aorta, positioning of an intra-aortic balloon pump (IABP) in the left ventricle (LV) through the apex (tightened with pledget-reinforced purse strings) and finally placing of a fluid line in the LV through the left atrial appendage (tightened with a pledget-reinforced purse string). The LV was filled with saline to the desired pressure through the fluid line and the IABP was switched on and set to a desired frequency [usually 60-80 beats per minute (bpm)]. A high-fidelity simulation has known limitations, but a more complex, realistic training environment with an actual beating (human) heart strengthens the entire training exercise and is of incremental value. All types of coronary artery anastomosis can be trained with this model. Training should be performed under the supervision of an experienced OPCAB surgeon and training progress is best evaluated with serial Objective Structured Assessment of Technical Skills (OSATS). A score of at least 48 points on the final OSATS ('good' on all components) is recommended before trainees can start their training on patients. The entire set-up provides a versatile training model to help develop and improve the skills required to safely perform beating heart OPCAB anastomoses.

3D printing: a valuable resource in human anatomy education.

Anatomy is essential to the health and medical professions: by learning anatomy, medical students learn about the structure of the human body, providing them with the basic tools needed for understanding pathology and clinical problems. In the past century, dissection and lectures formed the basis of anatomy education worldwide. More recently, traditional anatomy education based on topographical structural anatomy taught in lectures and in gross dissection classes, has been replaced by a multiple range of study modules, including problem-based learning, plastic models and/or computer-assisted learning and curricula integration (Louw et al. 2009). The anatomy field is strongly confident that donated bodies can still benefit new medical students significantly, and that dissection and pro-section procedures cannot be underestimated in a modern medical curriculum (Louw et al. 2009). Nevertheless, dissection and light microscopy are not problem-free. Storing human bodies is expensive, and other issues such as preservation and reduced suitability for dissection due to illness, age or obesity could be a problem; moreover, careful dissection is time-consuming and microscopy equipment can be expensive. Aside from biological and methodological matters, dissection and prosection have also issues concerning ethical convictions and legal restrictions or simply logistical problems due to lack of space, funds, recruitment, or proper furniture and equipment. Considerable variations in the legal and ethical frameworks concerning body bequests for anatomical examination exist worldwide based on cultural and religious variations as well as different legal and constitutional backgrounds. For instance, there are different views concerning the ‘‘ownership’’ of cadavers or the acceptability of using unclaimed bodies that have not given informed consent (McHanwell et al. 2008). In addition to known methods such as plastination and Thiel method embalming, a new three-dimensional printing system (3D printing) has been developed recently—an innovative approach that could become a valuable resource in anatomy education. 3D printing (also known as additive manufacturing or rapid prototyping) has existed since the late 1980s but has seen rapid advancements more recently because of decreased cost, computer engineering, and expanding applications. Rapid prototyping involves creating a physical 3D model from a computerised mould. The technology has been used in industrial processes to create forerunners of intended final products; models can be also analysed and modified before production is planned (Gibson et al. 2010). Basically, the principle of rapid prototyping is to use 3D computer models for the reconstruction of a 3D physical model by the addition of material layers (Gibson et al. 2010). With additive fabrication, the machine reads in data from a CAD drawing and lays down successive layers of liquid, powder, or other sheet material, and in this way builds up the model from a series of cross sections. These M. Vaccarezza (&) V. Papa Department of Human, Social and Health Sciences, University of Cassino and Southern Lazio, Campus Folcara, via S. Angelo in Theodice, 03043 Cassino, FR, Italy e-mail: m.vaccarezza@uq.edu.au; m.vaccarezza@unicas.it