The Structure of the Brachial Plexus of the Djungarian Hamster (Phodopus sungorus)

Hamsters are often chosen as companion animals but are also a group of animals frequently subjected to laboratory tests. As there are no scientific publications providing information on the anatomical architecture of the brachial plexus of the Djungarian hamster, this study analyses the structure of this part of the nervous system of this species. It is important to know the details of this structure not only for cognitive reasons, but also due to the increasing clinical significance of rodents, which are often used in scientific research. The study was conducted on 55 specimens. Like in humans, the brachial plexus of the Djungarian hamster has three trunks. The following individual nerves innervating the thoracic limb of the Djungarian hamster: the radial nerve, median nerve, ulnar nerve, musculocutaneous nerve, axillary nerve, suprascapular nerve, thoracodorsal nerve, cranial pectoral nerves, caudal pectoral nerve, lateral thoracic nerve, long thoracic nerve, and subscapular nerves. Similarly to other mammals of this order, the brachial plexus of the Djungarian hamster ranges widely (C5-T1). However, its nerves are formed from different ventral branches of the spinal nerves than in other mammals.

Nerve Transfers for Restoring Elbow Flexion in Brachial Plexus Palsy

Nerve transfers (NT) consist in sectioning a donor nerve and connecting it to the distal stump of a recipient unrepairable nerve. For elbow flexion restoration in brachial plexus palsy (BPP) we used different NT: 1) GF motor Ulnar Nerve to Biceps nerve (Oberlin technique), 2) Double fascicular median/ulnar to biceps/brachialis nerve transfer (Mackinnon), 3) InterCostal Nerves (ICN) to MCN (+/− nerve graft), 4) Medial Pectoral Nerve (MPN) to MCN, 5) ThoracoDorsal Nerve (TDN) to MCN, 6) Spinal Accessory Nerve (SAN) to MCN transfer, 7) Phrenic Nerve (PhN) to MCN, 8) Cervical Plexus C3-C4 to MCN and 9) Contralateral C7 (CC7). I want to present my personal experience using the phrenic nerve (PhN), the intercostal nerves (ICN) and Oberlin’s technique. The aim of this retrospective study is to evaluate the results of this procedure in BPP. NT is an important goal in BPP. ICN transfer into the nerve of biceps for elbow flexion recovery is a reliable procedure in BPP. ICN transfer for triceps offers a positive alternative (Carroll transposition). Oberlin technique is simple and offers better results in a shorter amount of time and is an effective and safe option.

Anatomical aspects of the use of the thoracodorsal nerve as a donor in musculocutaneous nerve ­injury

Aim. To assess the anatomical possibility of the use of the thoracodorsal nerve as a donor for nerve transfer to the musculocutaneous nerve. Methods. Anatomical dissection of the brachial plexus with layer-by-layer dissection of secondary bundles, short and long branches was performed in 121 male and female corpses. The localization of the origin of thoracodorsal and musculocutaneous nerves relative to the clavicle, the takeoff angle (degrees) from the secondary bundle, the length (in centimeters) of the nerves from the site of origin to the latissimus dorsi muscle entry point and the perforation of the coracobrachialis muscle, respectively, were investigated. The length of the thoracodorsal nerve with and without extramuscular branches was studied separately. Results. It was revealed that, in 58.7% of cases, the thoracodorsal nerve has the optimal length required for transposition to the musculocutaneous nerve. The excess length of the thoracodorsal nerve was between 0.1 and 9.1 cm. In 41.3% of cases, the length of the thoracodorsal nerve is not enough for transposition. Of these, in 17.4% of cases, the shortage of the length of the thoracodorsal nerve was 2 cm or less, which categorically does not allow its transfer to the musculocutaneous nerve. Only in 5% of cases, the length of the nerve was not enough for transposition in the use of the thoracodorsal nerve with extramuscular branches. Conclusion. Due to tension in many cases, the thoracodorsal nerve transfer to the musculocutaneous nerve can be performed with difficulty, and in some cases it is impossible, solving the problem in this category of people dictates the development of new surgical techniques with the thoracodorsal nerve or the use of another nerve as a donor.

Variations in Subscapularis Muscle Innervation—A Report on Case Series

Background and objectives: The subscapularis muscle is typically innervated by two distinct nerve branches, namely the upper and lower subscapular nerve. These usually originate from the posterior cord of the brachial plexus. A large number of variations have been described in previous literature. Materials and Methods: Dissection was carried out in 31 cadaveric specimens. The frequency of accessory subscapular nerves was assessed and the distance from the insertion points of these nerves to the myotendinous junction was measured. Results: Accessory subscapular nerves were found in three cases (9.7%). According to their origin from the posterior cord of the brachial plexus proximal to the thoracodorsal nerve all three nerves were identified as accessory upper subscapular nerves. No accessory lower subscapular nerves were found. Conclusion: Accessory nerves occur rather commonly and need to be considered during surgery, nerve blocks, and imaging procedures.

The features of the intrafascicular structure of the thoracodorsal nerve trunk in terms of ­restoring afferent innervation in breast reconstruction

Aim. To study of anatomical and topographic features and the intrafascicular structure of the thoracodorsal nerve trunk in the brachial plexus. Methods. The study was performed on the brachial plexus preparations of 80 male and female corpses. Short and long branches, secondary bundles, primary trunks, spinal nerves, anterior and posterior roots of the spinal cord were layer-by-layer anatomically prepared from brachial plexus. The angles of inclination from the arising site of the thoracodorsal nerve, the topography throughout and after entering the latissimus dorsi muscle were studied. The length and thickness of the thoracodorsal nerve, including the extramuscular and intramuscular parts, were measured. After isolation and fixation of the preparations, intrafascicular dissection of the thoracodorsal nerve was performed throughout the brachial plexus, by using microsurgical instruments and a binocular magnifier. Results. The length of the thoracodorsal nerve consists of extramuscular and intramuscular parts and was equal to 17.9 cm, of which the extra-muscular part was three-quarters of the total length of the nerve. The nerve trunk dissection revealed that the thoracodorsal nerve consists of 14 nerve fascicles and most frequently, in 46.2% of preparations, the thoracodorsal nerve arises from the C7 nerve root. The presence of motor and sensory portions of nerve fibers in the thoracodorsal nerve was found. In 90.2% of the preparations, the motor portion was located in the posterior-lateral part of the nerve and sensory in the anterior-medial. In most cases, both the sensory and motor fascicles arose from C7, or motor fascicle from C7 and sensory from C8. Conclusion. The intrafascicular dissection of the thoracodorsal nerve revealed microtopography of the sensitive and motor portions of nerve fibers in the nerve and along the entire length of the brachial plexus; in breast reconstruction, after mastectomy with thoracodorsal flap for the preservation of afferent innervation, it is recommended to cross only motor fibers of the thoracodorsal nerve.

Latissimus Denervation: A Review of Evidence

Background Breast reconstruction is becoming an increasingly important and accessible component of breast cancer care. Among the many reconstructive options available, the latissimus dorsi flap has experienced a renewal in popularity because of its favorable properties and outcomes when used for breast reconstruction. However, a limitation unique to latissimus-based reconstruction is inappropriate breast animation postoperatively, due to persistent thoracodorsal innervation of the latissimus dorsi muscle after transfer to the mastectomy site. Methods A comprehensive literature search of PubMed and MEDLINE was conducted for studies investigating the role of thoracodorsal denervation in latissimus-based breast reconstruction. Data on surgical techniques, type of intervention, objective outcome measurements, and patient satisfaction-based outcomes were reported. Additional data included patient sample size, follow-up length, and treatment of thoracodorsal nerve (e.g., resection versus transection and length of transection) when applicable. Results Sixty-six search results were reviewed for inclusion and nine qualified after exclusion criteria for a total of 361 patients undergoing either unilateral or bilateral latissimus flap reconstruction. Successful thoracodorsal denervation rates were included in most studies and outcomes measurements were heterogeneous. Eight out of nine studies included patient-reported symptoms of breast animation postoperatively. Based on these findings, a systematic approach is presented. Conclusion We present this review to elucidate successful practices, identify current gaps in knowledge, and offer a systematic approach to this clinical challenge.