[Learning and optimising minimally invasive techniques by operating on embalmed human corpses]

Educational training in laparoscopic gynecological surgery based on ethanol-glycerol-lysoformin-preserved body donors

PURPOSE

Educational training of laparoscopic skills performed on body donors is considered the gold standard prior to surgery in living patients. Appropriate, safe, and feasible fixation of body donors, reflecting true-to-life conditions of tissues, is an essential prerequisite for training workshops.

MATERIALS AND METHODS

Here we describe and evaluate a modified ethanol-glycerol-lysoformin-based fixation technique. Body donors were fixed by perfusion (70% ethanol, 30% glycerol, 0.3% lysoformin; ca. 20l) via femoral artery and stored in a humid atmosphere (1% thymol) at 4°C. Technical equipment included a mobile operating table, endoscopy system with gas insufflation, suction/irrigation pump, standard and electrosurgical instruments. The tissue properties of ethanol-glycerol-lysoformin-fixed body donors and their suitability for laparoscopic surgery were tested and compared to the in vivo situation.

RESULTS

Modified ethanol-glycerol-lysoformin fixation was a simple, cost-efficient and hazard-free procedure, resulting in near-to-life tissue conditions regarding consistency and flexibility, with moderate discoloration and greater viscosity of organs. Key laparoscopic procedures (trocar handling, pneumoperitoneum, blunt/sharp dissection, partial/total removal of organs, bi- or monopolar electrosurgery, suturing techniques) could be performed without difficulty. Multiple reuse of body donors was feasible over one year. Compared to the in vivo situation, the investigation of body donors required a greater degree of gas insufflation and more energy for electrosurgery.

CONCLUSIONS

Modified ethanol-glycerol-lysoformin fixation applied to body donors permitted laparoscopic surgery in a realistic and practical manner. Due to its logistic advantages, this technique provides appropriate conditions to train laparoscopic skills and implement novel minimally invasive approaches.

Can clinical examination cause a Stener lesion in patients with skier's thumb?: a cadaveric study

Approximately one-third of all injuries of the upper limb and 7% of all injuries in skiing affect the ulnar collateral ligaments of the thumb metacarpophalangeal joint (skier's thumb). In some patients the collateral ligaments are displaced proximally over the adductor aponeurosis, resulting in a so-called Stener lesion. In these cases surgical treatment is indicated. We hypothesized that a Stener lesion could be provoked by clinical stability testing in patients with a skiers thumb and performed a cadaveric study on 10 Thiel fixated cadaver hands. For clinical stability testing, the thumb was manually deviated in radial direction in both 30° flexion and extension of the MP-joint. It was performed with maximum strength by two hand surgeons after sequential detachment of the ulnar collateral ligaments. After every sequence, it was assessed if the clinical stability testing had caused a Stener lesion. All of the 10 cadavers showed identical results while testing the clinical stability. A decreased stability was only found after cutting both parts of the ulnar collateral ligaments. A Stener lesion could not be provoked in any of the cadavers at any time by clinical stability testing. Summarizing our findings we conclude that a proper performed clinical stability testing of the thumb MP joint is a safe maneuver, which does not lead to a Stener lesion in patients with skier's thumb.

Thiel embalming technique: a valuable method for teaching oral surgery and implantology

BACKGROUND

Because of its high requirements on surgical experience and the need of complete understanding of the anatomy, oral surgery and especially implantology belong to the most demanding procedures in dentistry. Therefore, hands-on courses for oral surgery and implantology are considered a prerequisite to prepare for clinical practice. To achieve teaching conditions as realistic as possible, we used a novel human cadaver embalming method enabling tissue dissection comparable with the living body.

METHODS

Thirty cadavers which were offered by the Institute of Anatomy for the purpose of running oral surgery and implantology courses were embalmed in the technique described by Thiel. On each cadaver, dissection of soft and hard tissue and implantological procedures were performed according to a structured protocol by each course participant. The conservation of fine anatomical structures and the suitability of the embalmed tissue for dissecting, drilling, and suturing were observed and photographically documented.

RESULTS

By means of the Thiel embalming technique, oral surgery and implantological procedures could be performed under realistic conditions similar to the living body. Due to the conservation procedure, preparations could be carried out without any time limit, always maintaining the same high quality of the tissue. The maxillary sinus membrane, mucosa, bone, and nerves could be exposed and allowed dissecting, drilling, and suturing even after weeks like fresh specimens.

CONCLUSION

The Thiel embalming method is a unique technique which is ideally suited to practice and teach oral surgery and implantology on human material.

[ElePhant: an anatomic-electronic simulation system for the evaluation of computer assisted interventions and surgical education]

BACKGROUND

Suitable simulation systems providing realistic conditions are required for preclinical evaluation of computer assisted interventions and surgical training. Techniques are necessary for an objective detection of injuries to the structures at risk. The aim of this study was the technical realization of a simulation system for the ENT intervention, mastoidectomy.

MATERIALS AND METHODS

The basis of the simulation system was a CT scan of a cadaver skull. Using 3D printing, an anatomical phantom with realistic bone-like properties was created. Electronic detection systems were integrated into the structures at risk. A study with 16 ENT surgeons was conducted to prove the system's suitability for surgical training.

RESULTS

The creation of simulation systems for the objective evaluation of surgical intervention qualities is feasible. A modular structure enables economic and simple replacement of the simulation area. The modules are cost effective and reproducible with high accuracy. The present study shows that the simulation system can be applied in surgical education and evaluation as an alternative to cadavers.

CONCLUSION

Objective evaluation of injured structures at risk can be realized in real time. The simulation system permits preclinical evaluation studies of computer assisted instruments and surgical education. Reproducibility of the results makes multi-center studies possible.