Zygomatic Implant Length Measurement Without Excessive Flap Release: A Human Cadaver Study.

One of the most important steps in zygomatic implant surgery is to determine the implant length. This cadaver study aims to identify an alternative technique for determining the length of the implant in zygoma surgery without excessive elevation of the flap. A total of 30 cadavers were included in this study. Measurements were made with a probe by seeing the exit point of the drills from the lateral aspect of the zygomatic bone. Secondly, without excessive flap release, the distance that the depth probe first raises the skin over the lateral border of the zygoma is measured. The average difference between the measurements made without excessive elevation of the flap and with a retractor placed on the zygomaticofrontal notch was found to be 5.41 ± 0.94 mm (range: 5-7.5 mm). According to the results of this study, the zygomatic implant should be placed at least 5 mm shorter than the length at which the depth probe first raises the skin over the lateral border of the zygomatic bone.

Intramuscular nerve distribution of the sternocleidomastoid muscle for the botulinum toxin injection.

PURPOSE: The aim of this study is to define the intramuscular nerve distribution of the sternocleidomastoid muscle (SCM) and the innervation zones (IZ) to describe the optimal botulinum toxin injection sites. METHODS: The cricoid cartilage (CC), laryngeal prominence (LP) and hyoid bone (HB) and angle of mandible (AM) were determined as landmarks. The length of the muscles were measured between the sternoclavicular joint and tip of the mastoid process. SCM was evaluated in two parts as anterior and posterior divided by the line where the length of the muscle was measured. Measurements were made to define the relationships of the SCM with common carotid artery, internal and external jugular veins. IZ were described according to these vessels. Afterwards, Modified Sihler's staining technique was applied to expose the intramuscular nerve distribution. RESULTS: The average length of SCM was 160,1 mm. Motor entry point of the accessory nerve fibers were between the AM-HB lines, in the range of 30-40% of the muscle length, and in the posterior part of the muscles. IZ were between the HB-CC lines in the anterior and posterior part. When this interval was examined according to the vessels, the optimal injection sites were between the LP-CC lines. CONCLUSIONS: This study shows the position of the intramuscular nerve fibers endings of the SCM according to the chosen landmarks and the relationship of the IZ with the vessels to prevent complications. These results can be used as a guide for safe and effective botulinum toxin injections with optimal quantities.

Comparison of pulley plasty, pulley venting and resection of flexor digitorum superficialis slip after zone II flexor tendon repair: a cadaver study.

LEVEL OF EVIDENCE: V.

The Myrtiformis Muscle: Identification of a Forgotten Entity That Is Distinct From the Depressor Septi Nasi Muscle.

INTRODUCTION: Nasal musculature anatomy is a topic that plastic surgeons pay attention to. However, the presence and role of the myrtiformis muscle (MM) remain controversial. To elucidate these aspects, an anatomy-based study was conducted. MATERIALS AND METHODS: Seven midsagittally split and two total cadaver head's nasal bases, embalmed with modified Larssen solution (MLS), were dissected for MM anatomy. The features of this muscle were photographed, and a video of its function was recorded. RESULTS: It was found that MM originates from the maxillary alveolar process and continues as two heads, one reaching the alar base with spicular fibrotendinous endings and the other extending to depressor septi nasi fibers. Owing to its bi-vectoral muscle fibers, MM is found to constrict the nares by simultaneously forcing the alar base and lowering the columella. It was also found that left-sided muscles were larger than right-sided muscles. CONCLUSIONS: The MM is found to be a constrictor muscle of the nares in this study, contrary to recent observations.

A Feasible Technique for Transoral Endoscopic Thyroidectomy Through Vestibular Access Using a Single-port Technique: A Video Vignette in Cadaver Dissection.

BACKGROUND: The aim of this study was to evaluate the safety and feasibility of a single-port system for transoral endoscopic thyroidectomy with vestibular access (TOETVA). MATERIALS AND METHODS: Two embalmed human cadavers were used to test the single-port technique. After positioning, a median vestibular incision was made. Adipose tissue was dissected through the mentum with a Kelly clamp to reach the subplatysmal level. The Keyport Single Port System (Richard Wolf) was then inserted. After port placement, flexible endoscopic dissectors and a 5-mm endoscope were advanced. After removing the dissectors, we inserted the ArtiSential laparoscopic instruments. We also used a 3-port TOETVA on another human cadaver to compare the results with those of the single-port surgery. RESULTS: In the first cadaver, skin tension was observed during trocar insertion and dissection. Trocar insertion resulted in skin perforation in the submental area. In the second cadaver, the single-port trocar was successfully inserted despite the significant skin tension. However, the trocar did not allow the necessary surgical maneuvers to proceed with subsequent surgical steps and create a working space. Postprocedural anatomic dissection revealed that the distal branches of the mental nerve were related to the trocar passage. CONCLUSIONS: Our cadaver study demonstrated that single-port TOETVA is unsafe and not feasible with the current technology of the Keyport single-port system. This approach needs to be improved to perform this technique without injury to distal branches of the mental nerve, skin perforation, and other complications.

Modified Larssen solution (MLS)-fixed cadaver model for transoral endoscopic thyroidectomy vestibular approach (TOETVA) education: a feasibility study.

BACKGROUND: Training formats for transoral endoscopic thyroidectomy vestibular approach (TOETVA) are limited. Our aim was to create and investigate a TOETVA training model for general and ENT surgeons. METHODS: A total of 15 modified Larssen solution (MLS) human cadavers were used in the study. A day duration TOETVA human cadaver workshops were offered in two years consecutive. Post-training verbal and online questionnaires were applied to all trainers to evaluate course structure and program, organoleptic characteristics of MLS-fixed human cadavers, and TOETVA training effectiveness. Cost assessment is included in the study. RESULTS: Ninety-eight participants, i.e., 14 trainers and 84 hands-on (HO) and observer (OB) trainees, attended the workshops, completed the tasks assigned, and fulfilled the questionnaires. Implementation of all steps of TOETVA was approved positively by 89.8% of all participants, 94.4% of HO, and 83.3% of OB trainees. Regarding human cadaver and teaching quality, 10.8 ± 0.8 (10-12) human cadavers were "practical" by 13.2 (94.5%) of the trainers, and by 33.3 (92.5%) of the trainees for all steps of TOETVA. The cadavers were stored for 4.53 years and used 6.27 times repeatedly for endoscopic workshops and research studies. TOETVA workshop cost with repeatable use of MLS-fixed human cadaver is half of other performed TOETVA workshops. CONCLUSIONS: A TOETVA human cadaver workshop model has not been reported yet. Our findings suggest the feasibility of MLS-fixed human cadaver model for training of TOETVA, preserve the organoleptic properties necessary for the implementation of surgical steps, and reduce the cost.

Verification of Endotracheal Tube Position by Emergency Nurses Using Ultrasound: A Repeated Measures Cadaver Study.

INTRODUCTION: Endotracheal intubation is a lifesaving procedure frequently performed in emergency departments. It is associated with some potential risks. Rapid and reliable confirmation of endotracheal tube placement during intubation is critical. Nurses play an important role in the care of patients in various settings. Ultrasound can be performed and interpreted not only by physicians but also by nurses. The aim of this study was to evaluate how well nurses without previous ultrasound experience can determine both esophageal and tracheal localization of endotracheal tubes in cadavers after a short ultrasound training. METHODS: This was a repeated measures study with an educational intervention and no control/contemporaneous comparison group. The study was performed to evaluate the ability of emergency nurses to confirm correct endotracheal tube placement and identify esophageal intubations. A total of 7 emergency nurses were given theoretical education and hands-on training about ultrasound. They diagnosed tracheal or esophageal intubation using ultrasound. RESULTS: Four cadavers were used 8 times each for the study. A total of 32 intubation procedures were evaluated with ultrasound by each nurse. In the analysis based on 224 responses, sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and overall accuracy of ultrasound applied by nurses to detect tracheal intubation were 95.61% (90.06%-98.56%), 97.27% (92.24%-99.43%), 35.06 (11.48-107.10), 0.05 (0.02-0.11), and 96.43% (93.08%-98.45%), respectively. The mean time to evaluate the tube location by ultrasound was 6.57 seconds. DISCUSSION: The results support that ultrasound can be performed by nurses for the confirmation for esophageal and tracheal intubations quickly and accurately.

Characterization of the mechanical properties of human parietal bones preserved in modified larssen solution, formalin and as fresh frozen.

PURPOSE: Although the fresh frozen (FF) cadaver is preferred for surgical applications, it is limited due to short usage time, unsuitable for reuse and the risk of infection. Due to its limited use, FF cadavers, which are covered by import in countries with insufficient body donation cause low-cost effectiveness. With the increase of real human tissue specimen necessities for surgical training, long-term preservation of the cadavers is crucial due to changes in mechanical properties. Therefore, studies on embalming solutions have increased in recent years. METHODS: We quantify the biomechanical properties of human parietal bones preserved via modified larssen solution (MLS) and compare the results with the specimens preserved as FF and fixed with 10% formalin-based solution (F10). The rectangular samples of 24 parietal bones of male individuals were resected from MLS-embalmed, F10-embalmed and FF cadavers to form three groups each containing eight samples. These specimens were tested longitudinally to identify mechanical properties. RESULTS: The tensile test results showed that there is not a significant difference between the groups in terms of stiffness, elastic modulus, strain at ultimate stress, failure strain and effective plastic strain. However, the yield stress, ultimate stress, yield strain, failure stress and total energy and post-yield properties are significantly lower in F10 than MLS and FF groups. CONCLUSION: It is observed that the mechanical properties of MLS preserved and FF parietal bones have almost similar properties. Thus, it can be concluded that MLS is a suitable fixative solution for bone studies and bone-related surgical anatomy training applications.

A surgical and anatomo-histological study on Transoral Endoscopic Thyroidectomy Vestibular Approach (TOETVA).

BACKGROUND: The number of TOETVA surgeries has increased worldwide but the anatomical passage of trocars is not clearly defined. We aimed to define detailed surgical anatomical passage of the trocars in cadavers. The incisions in oral vestibule, anatomical pathways of trocars, affected mimetic muscles, neurovascular relations of trocars and histological correlation of surgical anatomy were investigated. METHODS: Four cadavers and 6 six patient oral vestibules were used. The locations of optimised vestibular incisions were measured photogrammetrically. Initial steps of TOETVA surgery were performed on cadavers according to those optimal incisions. TOETVA preformed cadavers dissected to determine anatomical passages of the trocars. Afterwards, flap of lower lip and chin were zoned by software appropriate to the trocars routes. Histological analyses of the zones were made in correlation with dissections. RESULTS: Mimetic muscles associated with median (MT) and lateral trocars (LT) are orbicularis oris, mentalis, depressor anguli oris, depressor labii inferioris and platysma muscles. Trocars affect mimetic muscles in the perioral, chin and submental regions in different ways. The risk of mental nerve injury by MT is low. LT pass through the DLI muscle. The transmission of LT to the subplatysmal plane in the submental regions can be in two different ways. The arterial injury risk is higher with LT than the MT. CONCLUSIONS: The surgical anatomy of the perioral, chin and submental regions for the initial TOETVA steps has been defined. Detailed surgical anatomical passages of the MT and LT were determined. Anatomical pattern to reach subplatysmal plane are presented. Mimetic muscles effected by trocars were determined. Endocrine surgeons should know the anatomical passage of TOETVA trocars.

Comparison of ultrasound and dorsal horizon radiographic view for the detection of dorsal screw penetration.

OBJECTIVE: The aim of this study was to compare the efficiency of dorsal tangential fluoroscopy and ultrasonography in detecting dorsal screw penetration in distal radius volar locking plate applications. METHODS: Ten cadaveric forearms were operated. The distal four screws were protruded 0, 1 and 2 mm into each of the second, third and fourth dorsal compartments of distal radius. Dorsal horizon views were taken using fluoroscopy. Each radiographic image was evaluated by two orthopedic surgeons who are blinded to procedure. Sonographic evaluations were performed by an orthopedic surgeon blinded to the procedure. Both dorsal horizon view and ultrasonography assessments were noted by the evaluators whether the tip of the screw penetrated or not the dorsal cortex for each compartment. RESULTS: No significant difference was observed on correct detection of 0 mm, 1 mm and 2 mm screw penetrations at second and third compartments. In the fourth compartment, there was no difference with 0 mm and 2 mm penetrations but correct detection accuracy of 1 mm screw penetration was 87% in ultrasonography group and 71% in dorsal horizon view group. CONCLUSIONS: The accuracy of ultrasonography on 1 mm penetration at the fourth compartment is better than dorsal horizon view. However, dorsal horizon view and ultrasonography accuracy is similar for the other compartments and penetration levels. Ultrasonography is a reliable and effective procedure for detection of dorsal screw penetrations. LEVEL OF EVIDENCE: Level III, Diagnostic study.

Cadaver embalming fluid for surgical training courses: modified Larssen solution.

PURPOSE: 10% Formalin (F10)-fixed cadavers have disadvantages such as disturbing smell, mucosal irritation, discoloration and rigidity. We aimed to determine a suitable, simple and cost-effective embalming method that preserves color, texture, pliability and flexibility of the tissues for a long time without a disturbing smell and mucosal irritation. The embalmed cadavers were expected to be durable against environmental effects, utilizable for multiple and repetitive surgical trainings and instrumentations. METHODS: Eight male (six intact, two autopsied bodies) and four female (three intact and one imported trunk) human cadavers were preserved with modified Larssen solution (MLS). Preserved bodies were kept in the deep freezers at -18/-20 °C. Bodies were allowed to thaw at room temperature 3 days prior to use. They were used in postgraduate hands-on courses for several medical disciplines. Each course lasted at least 1 day and during this period the bodies were stayed at room temperature. Assessments of 30 trainers and 252 trainees were collected during the courses. Additionally, the organoleptic characteristics of the fresh frozen (FF), preserved with MLS and F10-fixed cadavers were compared. RESULTS: The colors of muscles, fasciae, fatty tissue, nerves and vessels were evaluated and life-like tissues of MLS cadavers were impressive. There were no obvious or disturbing smell and sign of putrefaction of the MLS cadavers. CONCLUSIONS: MLS is a sustainable and relatively affordable soft cadaver embalming method. Its application is same as in other conventional methods and does not need new equipment. This article indicates the success of the MLS method in human cadavers.

Oxytocin provides protection against diabetic polyneuropathy in rats.

PURPOSE: The aim of the present study is to investigate the protective effects of oxytocin (OT) on diabetic neuropathy (DNP) in rats. MATERIALS AND METHODS: Eighteen rats were used to induce diabetes using single dose streptozotocin (STZ, 60 mg/kg). Diabetic DNP was verified by electromyography (EMG) and motor function test on 21st day following STZ injection. Six rats served as naïve control group and received no drug (n = 6). Following EMG, diabetic rats were randomly divided into three groups and administered with either 1 ml/kg saline or 80 µg/kg OT or 160 µg/kg OT intraperitoneally for four weeks. Then, EMG, motor function test, biochemical analysis (plasma lipid peroxides and glutathione), histological, and immunohistochemical analysis of sciatic nerves (bax, caspase 3, caspase 9, and NGF) were performed. RESULTS: Diabetic rats developed neuropathy, which was apparent from decreased compound muscle action potentials amplitudes and prolonged distal latency in saline-treated rats (p < 0.001) whereas 160 µg/kg OT significantly improved EMG findings. OT treatment significantly lessened the thickening of perineural fibrosis when compared with saline group (p < 0.001). Besides, OT significantly reduced plasma lipid peroxides (p < 0.05) and increased glutathione levels in diabetic rats (p < 0.001). The sciatic nerves of saline-treated rats showed considerable increase in bax, caspase 3 and caspase 8 expressions (p < 0.001) while OT treatment significantly suppressed these apoptosis markers. Also, OT improved NGF expression in diabetic rats compared to saline group. CONCLUSION: Present results demonstrate that OT appears to alleviate harmful effects of hyperglycemia on peripheral neurons by suppressing inflammation, oxidative stress and apoptotic pathways.

Revisiting the Anatomy of the Facial Recess: The Boundaries of the Round Window Exposure.

BACKGROUND: The exposure of the round window (RW) through the facial recess (FR) is sometimes partial. The anatomic variations that alter RW exposure during cochleostomy have not been clearly defined to date. AIMS: The aim of this study was to assess the best FR position in which to achieve the widest exposure of the RW niche and to define the topographic relationship between two other important anatomical structures, the facial nerve (FN) and the chorda tympani (CT). STUDY DESIGN: Cadaver study. METHODS: Twenty-four temporal bones were included in the study. Anterior and posterior epitympanectomy and posterior tympanotomy were performed after mastoidectomy. Bone was removed until the FN and CT were skeletonized and the CT branching point was visible. Two pictures were taken. The first was taken when the facial recess was at its widest exposure, while the second was taken when the RW niche was maximally exposed through the facial recess. Various measurements were taken. RESULTS: The RW niche was totally visible in 19 temporal bones (79.2%). The RW was partially visible in the remaining five bones (20.8%). The unexposed part of the RW lay posteromedial to the FN in these five bones. While the branching point of the CT could be visualized in all cases at the widest exposure of RW, the part of the FN distal to the branching point was hidden in eight subjects (33.3%) under the posterior wall of the external ear canal. CONCLUSIONS: The RW niche was totally visible in most of the temporal bones. The RW lay posteromedial to the FN in some cases and total exposure was impossible.

Anatomic Basis for Penis Transplantation: Cadaveric Microdissection of Penile Structures.

We present a cadaveric dissection study to investigate the anatomic feasibility of penile transplantation. Seventeen male cadavers were dissected to reveal detailed anatomy of the dorsal neurovascular structures including dorsal arteries, superficial and deep dorsal veins, and dorsal nerves of the penis. Dorsal artery diameters showed a significant decrease from proximal to distal shaft. Dominance was observed in one side. Deep dorsal vein showed a straight course and less decrease in diameter compared to artery. Dorsal nerves showed proximal branching pattern. In a possible penile transplantation, level of harvest should be determined according to the patient and the defect, where a transgender patient will receive a total allograft and a male patient with a proximal penile defect will receive a partial shaft allograft. We designed an algorithm for different levels of penile defect and described the technique for harvest of partial and total penile transplants.

The pleuro-esophageal muscle: a disregarded anatomical structure.

A transverse muscular band extending from the left pleura to the esophagus was detected during routine dissection of posterior mediastinum in Anatomy Department of Ege University Medical Faculty. As a result of a detailed review of the literature, we found that this structure is named as the pleuro-esophageal muscle. This muscle was made of smooth fibers, acting as an anchoring structure to the lower part of the esophagus. While the entire esophageal muscle is smooth in the early stage of fetal development, this muscle probably derives as an early separation from the esophagus.

Accessory tendon slip arising from the extensor carpi ulnaris and its importance for wrist pain.

OBJECTIVE: The anatomical variations of the extensor carpi ulnaris (ECU) muscle can cause a functional impairment of the wrist and the little finger. The aim of this study was to determine the number, thickness and type of accessory tendon arising from the ECU. METHODS: The presence of an accessory tendinous slip from the ECU muscle was examined in terms of gross appearance, size, shape, thickness, location and distribution in 54 cadaveric forearms. RESULTS: The accessory slips arising from the ECU muscle were observed in three specimens (5.6%) (two left, one right). These slips ran to the ulnar side of the extensor digiti minimi tendon, originated from the head of the ECU, and ended on the extensor apparatus of the fifth finger. The mean width of the tendinous slips was 1.4±0.01 mm. CONCLUSION: This anatomic variation of the ECU should be considered in diagnostic and surgical procedures involving the dorsum of the hand. Its clinical importance in the treatment of tenosynovitis and subluxation of joints is also stressed.

Anatomical similarity between tendons and Type 3 intertendinous connections: suitability as local donor tissue.

OBJECTIVE: A detailed anatomical knowledge of the extensor tendons of the hand is essential for accomplishing successful tendon repair. The aim of this study was to investigate the similarities between the extensor tendon and the thickest intertendinous connections (IC) in the 4th intermetacarpal space, where Type 3 IC is most frequently seen. METHODS: A total of 38 dissected hands were studied for anatomical structures that might serve as donor extensor tendons as well as for their relationship with the IC in the fourth intermetacarpal space of the dorsal hand. RESULTS: The most frequent anatomical pattern in the extensor tendons of the fourth intermetacarpal space were the two tendons from the extensor digiti minimi muscle (68.5%) and the thickest type of IC (90%). Other common findings detected at microscopy included the presence of a capsule in the structures associated with the tendon and IC, rich vascularization and high collagen content. CONCLUSION: Type 3 IC resembles tendons in strength and because of its histological similarity, the IC may be suitable to use in tendon repair. The fourth intermetacarpal space appeared to have the greatest tendon length and thickest IC content and is therefore a suitable donor graft tissue for local tendon repair.