Anatomical study of phrenic nerve course in relation to neck dissection

The course of the phrenic nerve in the neck region and its relationship with adjacent anatomical structures in the thoracic inlet

PUPOSE

This study aims to reveal the relationship of the phrenic nerve (PhN) with its neighboring structures in the lower neck region more comprehensively than previous studies and to minimize nerve damage by enabling invasive procedures in this region to be performed with high accuracy.

METHODS

Forty-one heminecks were evaluated. The relationship between the PhN and the anterior scalene muscle (ASM), internal thoracic artery (ITA), branches of subclavian artery (SA) and subclavian vein (SV) was examined.

RESULTS

It was observed that the PhN was located medial to the ASM in all cases. The distances were higher in male cadavers. The PhN was found to enter the thorax lateral to the ITA in 15/41 and medial to it in 25/41 sides. In 17/41 cases, the closest SA branch to the PhN was the thyrocervical trunk (TT) and in 24 cases the ITA. The PhN was located behind the SV in 38 cases and in front of it in 2 cases.The accessory PhN was found in 4/41 sides. There was no significant difference in morphometric findings between genders (p > 0.05). However, significant differences were observed between the parameters (p < 0.05).

CONCLUSION

The anatomy and variations of the PhN are of great importance in surgical interventions and invasive procedures in the neck region. The study provides important information to reduce the risk of damage to the PhN in surgical procedures. In addition, knowledge of the anatomical variations of the nerve may contribute to more successful results in nerve grafting and other surgical applications.

A quantitative analysis of the dimensions and content of the vertebral triangle

PURPOSE

The vertebral triangle (VT) located in the root of the neck most commonly contains the vertebral artery (VA), cervical sympathetic chain and certain roots of the brachial plexus. Although other structures have been reported, few studies have reported on the overall content of this space. Based on the current literature, there is a general paucity of anatomical information pertaining to the dimensional anatomy of the VT and specifically the structures related to it. Therefore, this study aimed to quantitatively analyze the size, position, content, and anatomical structures in relation to the vertebral triangle in a South African sample.

METHODS

Forty-three VTs were dissected on bodies donated to science. Measurements taken include the dimensions of the triangle, as well as distances between prominent structures and landmarks of the VT. Observations were made on the presence/absence of the varying neurovascular structures within the VT.

RESULTS

Mean height was 30.1 ± 1.51 mm (R) and 32.9 ± 1.78 mm (L). Mean width was 18.3 ± 0.74 mm (R) and 19.3 ± 0.98 mm (L). The C8 spinal nerve was found on average approximately halfway [16.4 ± 0.74 mm (R) and 15.9 ± 0.95 mm (L)] in the VT. The VA was present in the VT in 100% of the sample and the C7 spinal nerve and inferior sympathetic ganglia were present in more than 80% of the sample.

CONCLUSION

Understanding the VT and the content is of the utmost importance and of great interest to neurosurgeons, to avoid these important neurovascular structures and prevent iatrogenic complications during surgery.

Immersive Surgical Anatomy of the Craniocervical Junction

With the advent and increased usage of posterior, lateral, and anterior surgical approaches to the craniocervical junction (CCJ), it is essential to have a sound understanding of the osseous, ligamentous, and neurovascular layers of this region as well as their three-dimensional (3D) orientations and functional kinematics. Advances in 3D technology can be leveraged to develop a more nuanced and comprehensive understanding of the CCJ, classically depicted via dissections and sketches. As such, this study aims to illustrate - with the use of 3D technologies - the major anatomical landmarks of the CCJ in an innovative and informative way. Photogrammetry, structured light scanning, and 3D reconstruction of medical images were used to generate these high-resolution volumetric models. A clear knowledge of the critical anatomical structures and morphometrics of the CCJ is crucial for the diagnosis, classification, and treatment of pathologies in this transitional region.

A Rare Case of C2 Sensory Blockade with Preserved Phrenic Nerve Function in an Obstetric Patient

High neuraxial blockade is a serious complication in obstetric patients and requires prompt recognition and management in order to optimize patient outcomes. In cases of high neuroblockade, patients may present with significant hypotension, dyspnea, agitation, difficulty speaking or inability to speak, or even loss of consciousness. We report the unusual presentation of an obstetric patient that remained hemodynamically stable and had the preserved ability to initiate breaths despite sensory blockade up to C2. The presence of differential motor and sensory block documented in this case helped enable the patient to be managed with noninvasive ventilatory support until the high blockade regressed and we are not aware of any other similar reports in literature.

Marked lateral deviation of the phrenic nerve due to variant origin and course of the thyrocervical trunk: a cadaveric study

Phrenic nerve impairment can often lead to serious respiratory disorders under various pathological conditions. During routine dissection of an 88-year-old Japanese male cadaver, a victim of heart failure, we recognized an extremely rare variation of the right thyrocervical trunk arising from the subclavian artery laterally to the anterior scalene muscle. In addition to that, the ipsilateral phrenic nerve was drawn and displaced remarkably laterad by this vessel. We examined all of the branches arising from subclavian arteries, phrenic nerves and diaphragm muscles. The embryological background of this arterial variation is considered. The marked displacement with prolonged strain had a potential to cause phrenic nerve impairment with an atrophic change of the diaphragm muscle. Recently many image diagnostic technologies have been developed and are often used. However, it is still possible that rare variations like this case may be overlooked and can only be recognized by intimate regional examination while keeping these rare variations in mind.