Applied anatomy of the cervical region of the recurrent laryngeal nerve

BACKGROUND AND OBJECTIVE： To avoid recurrent laryngeal nerve （RLN） injury during thyroid surgery, it is important to identify the nerve and to follow its projection carefully to discriminate it from the inferior thyroid artery. DESIGN, TIME AND SETTING： All studies were performed at the Anatomy Division of Shaoyang Medical College from May 2003 to May 2004 with repeated measurement design. MATERIALS： Fifty embalmed adult corpses, comprising 20 females and 30 males, were obtained by donation. METHODS AND MAIN OUTCOME MEASURES： The projection, branches, and the relationship of the RLN to the inferior thyroid artery were observed. RESULTS： The RLN in all cases ascended through the tracheoesophageal groove at the isthmus superior levels of the thyroid gland. However, the RLN in 14 cases were situated inferior to the isthmus of the thyroid gland; 11 cases were to the right side and 2 cases to the left side, projected in the tracheoesophageal groove, and ascended away from the groove after 4.5-6.5 mm. The RLN typically ramified at the thyroid isthmus plane （44 cases, 44% of all cases）. The RLN branches were variable. Type 2 rami were most common in the RLN, accounting for 55%; the second most common was RLN branches with no rami. RLN braches with type 3 rami, 4 rami, and 5 rami were less common. Approximately 54% of nerves were situated behind the main branch artery. The nerves located adjacent to the arteries, and between the arterial branches, were similar; the former applied to 19 cases, accounting for 19%, whereas the latter applied to 18 cases, accounting for 18%. Left nerves behind the artery, and right nerves before the artery, were more common. There were significant differences between the left and right nerves （P 〈 0.01）. CONCLUSION： There was not a significant difference in the projection of the RLN, while a significant difference in the number of RLN branches existed. In addition, the anatomical relationship of the RLN and the inferior thyroid artery exhibited side differences.

Applied anatomy study of anterior tragal perforating artery(ATPA)

Objective To investigate anterior tragal perforating aftery( ATPA) and provide anatomic basis for flap derived from preauricular area. Methods Twenty ( 40 sides) cadaver heads fixed in 10% formalin solution and perfused with red - colored latex were used to perform gross anatomy study. Two heads of fresh cadaver

Applied anatomy of the path of retroperitoneoscopic surgery

Objective To discover the anatomical basis of retroperitoneoscopic surgery. Methods Twenty Chinese adult cadavers including 12 men and 8 women were anatomized. The relationship between nerves, vessels of the lateral abdominal wall, retroperitoneal structures and the path of retroperitoneoscopic surgery were measured. Results In male cadavers, the distance between the iliac crest and trigonum lumbale was 4.02±1.26 cm on the left, and 3.83 ± 0.90 cm on the right. The distance between the iliac crest and iliohypogastricus nerve was 0.82 ± 0.13 cm on the left and 0.84±0.08 cm on the right. The distance between the subcostal nerve and Ⅻ rib in the posterior axillary line and midaxillary line was 0.79 ±0.26 cm,1.65± 1.12 cm on the left and 0.78 ± 0.30 cm, 1.59 ± 1.07 cm on the right respectively. The distance between the ureter of inferior pole of kidney and extra-border of psoas was 2.24 ± 0.67 cm on the left and 2.19 ± 0.73 cm on the right. The distance between crossing of the ureter and iliac

Applied anatomy of radial midforearm flap pedicled with intermuscular branch of radial artery

To provide anatomic basis for transposition of vascularized radial midforearm flap.Methods On 40 adult cadaveric upper limb specimens injected with red dye,the origin,course,branchs,diameters and anastomosis of intermuscular branch of radial artery and its cutaneous branch were observed.Results Originating from radial artery,intermuscular branch of radial artery descended along periosteum closely between pronator teres and supinator,the main stem was (4.8±1.0)cm in length and (1.2±0.2)mm in diameter.After its periosteal branches were sent off to distribute over middle and inferior shaft of radius,its cutaneous branch perforated from intermuscle and deep fascia and anastomosed with some other cutaneous branches in the forearm.Perforating point of the cutaneous branch was located (11.1±1.3)cm beneath lateral epicondyle of humerus,its diameter was about (0.6±0.1)mm.Conclusion Radial midforrarm flap pedicled with intermuscular branch of radial artery can be transferred to repair soft tissue defect of elbow,forearm or hand.7 refs.

Applied anatomy for pituitary adenoma resection

Background Pituitary adenomas are common intracranial tumors, with a rising incidence in China. Excision is a mainstay therapy for this disease, and is often carried out via transfr0ntal, transsphenoidal or transpterional approaches. However, few studies have systematically addressed the regional anatomy involved in these microsurgical procedures. The present study attempted to establish some key anatomic measurements relevant to pituitary adenoma resection based on cadaver and computer tomography （CT） image studies. Methods Head specimens from 30 randomly selected formalin-fixed adult cadavers were used for anatomical analysis. Measurements were made on the base of the skull following removal of brain structures above the pituitary gland, and on the mid-sagittal plane of the cranium. Parameters were designed by considering the 3 above-mentioned common microsurgical approaches, and obtained on each head using a sliding caliper. Multi-level CT images from 30 individuals were also used for distance measurements between landmark structures that are relevant to these surgeries. All data were subjected to statistical analysis using the SPSS 11.5 software. Results There was statistically significant difference （P〈0.05） of distance measured on cadavers relative to CT images in 3 sets of measurements related to the transfrontal surgical approach, i.e., distances from the midpoint of superciliary arch superior border to the cranial entrance of internal carotid arteries （ICAs）, the opposite side entrance of ICA and to the genu of ICA. While regional anatomical analyses were carried out according to the transpterional approach, statistically significant difference was also found in 3 sets of distance measurements between cadaver and CT image data, with regard to the distances between the pterion and some landmark structures around the pituitary. Conclusions The present study provides key anatomical and CT image measurements involving the 3 conventionally used surgical approaches for pituitary tumor resection. The data implicate that while CT scan results can provide valuable guidelines for operations, cautions and adjustments are needed during surgery for sufficient tumor excision and protection of key blood vessels and nerves in the vicinity of the pituitary gland and around the surgical pathway.

Anatomic structural study of cerebellopontine angle via endoscope

Background Minimally invasive surgery in skull base relying on searching for possible anatomic basis for endoscopic technology is controversial. The objective of this study was to observe the spatial relationships between main blood vessels and nerves in the cerebellopontine angle area and provide anatomic basis for lateral and posterior skull base minimally invasive surgery via endoscopic retrosigmoid keyhole approach.Methods This study was conducted on thirty dried adult skulls to measure the spatial relationships among the surface bony marks of posterior cranial fossa, and to locate the most appropriate drilling area for retrosigmoid keyhole approach. In addition, we used 10 formaldehyde-fixed adult cadaver specimens for simulating endoscopic retrosigmoid approach to determine the visible scope.Results The midpoint between the mastoid tip and the asterion was the best drilling point for retrosigmoid approach. A hole centered on this point with the 2.0 cm in diameter was suitable for exposing the related structures in the cerebellopontine angle. Retrosigmoid keyhole approach can decrease the pressure on the cerebellum and expose the related structures effectively which include facial nerve, vestibulocochlear nerve, trigeminal nerve, glossopharyngeal nerve, vagus nerve, accessory nerve, hypoglossal nerve, anterior inferior cerebellar artery, posterior inferior cerebellar artery and labyrinthine artery, etc.Conclusions Exact location on endoscope retrosigmoid approach can avoid dragging cerebellum during the minimally invasive surgery. The application of retrosigmoid keyhole approach will extend the application of endoscopic technology.

Course of major paravertebral vessels and the positional relationship to the vertebral bodies in healthy Chinese subjects： a CT-based study

Background Several studies,including those done in China,report that paravertebral vascular injury during posterior spinal surgery can greatly harm patients,though it is a relatively rare complication.However,few studies have examined their course and anatomic relationship to the spine.The aim of this study was to measure the course of the major paravertebral vessels and their positional relationships to the vertebral bodies in Chinese subjects using computed tomography.Methods We studied a total of fifty subjects who underwent thoracolumbar computed tomography from T1-S1 at our institution.We measured the theoretical distance,actual distance,theoretical angle,and actual angle of the paravertebral vessels at each thoracolumbar intervertebral disc.Results The paravertebral artery actual angle at T4-L4 ranged from-11.41 to 79.75° and the actual distance from 16.98 to 52.53 mm.The actual angle of the inferior vena cava at L1-L5 intervertebral disc ranged from-40.75 to 34.50° and the actual distance from-36.63 to 61.69 mm.There was no significant difference in the actual angle of the paravertebral vein or in the actual distance in the thoracic segments according to gender （P ＞0.05）.However,the actual distance in the lumbar segments were significantly different according to gender （P ＜0.05）.Conclusions The major paravertebral vessels＇ course is closer to the mid-sagittal plane as they move posterior along the vertebrae,and the actual distance of the paravertebral artery and azygos vein increase,while the actual distance of the inferior vena cava decreases.The course of the lumbar paravertebral vessels varies,especially at L4/L5,and may be more prone to intraoperative injury in female subjects.