Microsurgical anatomy of the abducens nerve.

OBJECTIVE: To clarify the oriented classification, relationships, and variations of the abducens nerve and provide a detailed description of its microsurgical anatomic features. METHODS: A microsurgical anatomic dissection of the abducens nerve was performed in 100 specimens obtained from 50 adult cadaveric heads fixed in formalin and two adult cadaveric heads stained with hematoxylin and eosin for histological examination. Important neurovascular and structural relationships of the abducens nerve were observed. RESULTS: The abducens nerve was divided into five segments (cisternal, petroclival, internal carotid artery, fissural, and intraconal). It coursed in the petroclival venous confluence and there was a complex anatomic relationship. Two new types of abducens nerve variations were found. In one type, the duplicated nerve is split into two branches for a limited length in the cavernous sinus (CS). The other is a complex type, which has a complex course and pattern. This type of duplicated abducens nerve has a communicating branch in the cistern and numerous fasciculi in the CS. In addition, the two branches do not accompany each other for the entire course in the CS. CONCLUSION: The vulnerability of the abducens nerve results from diverse factors. The inferolateral trunk, which arises from the intracavernous segment of carotid artery (also called the artery of the inferior CS), is an important landmark for finding the abducens nerve and sympathetic nerve. Variations of the abducens nerve are not rare. Keeping variations of the nerve in mind is important during skull base operations and transvenous endovascular interventions. Understanding the relationship of the abducens nerve with adjacent structures will help us in preparing for safe surgery.

Microsurgical anatomy of the ocular motor nerves.

This study was designed to provide anatomic data to help surgeons avoid damage to the ocular motor nerves during intraorbital operations. The microsurgical anatomy of the ocular motor nerves was studied in 50 adult cadaveric heads (100 orbits). Dissections were performed with a microscope. The nerves were exposed and the neural and muscular relationships of each portion of the nerve were examined and measured. The superior division of the oculomotor nerve coursed between the optic nerve and the superior rectus muscle after it left the annular tendon, and its branches entered into the superior rectus muscle and levator muscle. A mean of five fibers (range 3-7) innervated the superior rectus muscle, and a mean of one fiber (range 1-2) followed a medial direction (84%) or went straight through the superior rectus muscle (16%). The inferior division of the oculomotor nerve branched into the medial rectus, inferior rectus and inferior oblique muscles. The trochlear nerve ended on the orbital side of the posterior one-third of the superior oblique muscle in 76 specimens. The abducens nerve ended on the posterior one-third of the lateral rectus muscle in 86 specimens. If the belly of the lateral rectus muscle was divided into three superior-inferior parts, the nerve commonly entered into the middle one-third in 74 specimens. Based on the observed data, microanatomical relationships of the orbital contents were revised.

[Effect of total knee arthroplasty under computer navigation on intraoperative blood loss and joint function recovery].

OBJECTIVE: To analyze the effect of computer navigation assisted total knee arthroplasty on intraoperative hemorrhage and postoperative joint function recovery in patients with knee osteoarthritis. METHODS: From February 2015 to December 2017, 65 patients with knee osteoarthritis treated by traditional total knee arthroplasty were retrospectively analyzed as the control group and 65 patients with knee osteoarthritis treated by total knee arthroplasty under computer navigation as the experimental group. Before operation, all patients showed red swelling pain of knee, pain of going up and down stairs, and pain and discomfort of waist when sitting up and standing up. All patients were treated with total knee arthroplasty. The control group was treated with traditional total knee arthroplasty, and the experimental group was treated with total knee arthroplasty under the computer navigation system. The operation related conditions of the two groups were recorded and compared including the operation time and hospitalization time; the changes of hemoglobin and hematocrit of the two groups were detected and compared before and 5 days after the operation; the blood loss of the two groups and the induced flow at each time point calculated and compared after the operation, and the perioperative allogeneic blood transfusion rate and average blood transfusion volume of the patients were recorded; The joint function scale (KSS) was used to evaluate the recovery of knee joint function before the operation, 6 and 18 months after the operation respectively and to record the incidence of postoperative infection, lower extremity venous thrombosis and other complications. RESULTS: All the patients were successfully operated and the prognosis of the wound was good. All the patients were followed up for an average of 18 months. The operation time of the experimental group was longer than that of the control group, and the hospitalization time was shorter than that of the control group (P <0.05) ; the KSS score of the two groups at each time point after operation was higher than that before operation, but the increasing range of the test group was higher than that of the control group (P<0.05) ; there was no significant difference between the two groups in the incidence of complications (P>0.05) . CONCLUSION: Under the guidance of computer navigation, total knee arthroplasty can prolong the operation time compared with single total knee arthroplasty, but it is more conducive to reduce perioperative blood loss, reduce the rate of postoperative allogeneic blood transfusion, ideal recovery of joint function, less complications, safety and reliability.

[Differentiation of hepatic oval cell into mature hepatocyte induced by hepatic stellate cells].

OBJECTIVE: To investigate the role of hepatic stellate cells in the differentiation of hepatic oval cells into adult hepatocyte. METHODS: The oval cell were cocultured with primary hepatic stellate cells (HSC) in the same well (M-coculture) or separately cultured with HSC by millIcell (S-coculture). Oval cells were cultured alone as control; the expression of adult hepatocyte marker HNF-4alpha, albumin, and oval cell marker AFP, CK-19 in each group were detected by real-time PCR and western-blot. Phenotype changes were observed by transmission electron microscope (TEM); PAS staining was used to detect the quantity of glycogen granule in oval cell. Albumin level in supernatant was detected using ELISA kit. RESULT: (1) The relative level of HNF-4alpha and albumin mRNA expression compared with pre-coculture: M-coculture: HNF-4a: 1.9+/-0.2, 10.7+/-1.2, 12.0+/-1.3; albumin: 5.7+/-1.6, 110.7+/-13.7, 173.6+/-22.3. S-coculture: 1.4+/-0.1, 3.2+/-0.6, 8.9+/-1.4 times; albumin: 2.9+/-1.4, 22.3+/-8.5, 96.3+/-16.3. The relative level of HNF-4a and albumin mRNA expression in coculture group (M- and S-coculture) were higher than control group (LSD-t: 32.98, 10.08, 13.38, 7.96; P less than 0.01); and a higher level of HNF-4a and albumin was found in M-coculture group compared to S-coculture group (LSD-t: 32.98, 25.65; P less than 0.01). The relative level of AFP and CK-19 mRNA expression compared with pre-coculture: M-coculture: 1.1+/-0.2, 0.2+/-0.0, 0.0+/-0.0; S-coculture group: AFP: 1.0+/-0.2, 0.2+/-0.1, 0.1+/-0.0; CK-19: 0.6+/-0.1, 0.1+/-0.0, 0.0+/-0.0; control group: AFP: 1.0+/-0.1, 1.0+/-0.1, 1.1+/-0.1, CK-19: 1.0+/-0.1, 1.1+/-0.1, 1.0+/-0.1. The relative level of AFP and CK-19 mRNA expression in coculture group (M- and S-coculture) were lower than that in control group (LSD-t: 37.99, 34.50, 13.59, 22.46; P less than 0.01). (2) The albumin secretion was detected in M-coculture: 14 day: (15.30+/-0.09) ng/ml, 21: (20.98+/-0.12) ng/ml; S-coculture: 14 day: (11.41+/-0.13) ng/ml, 21 day:(15.12+/-0.17) ng/ml. (3) It showed more organelles such as endoplasmic reticulum, mitochondrion and Golgi apparatus in oval cells cocultured with HSC. And cholangiole-like structure appeared between oval cells cocultured with HSC. (4) PAS staining showed glycogen granules could be observed in coculture groups. CONCLUSION: HSC can induce differentiation of oval cell into mature hepatocyte.