Objective To comment on the recent advances of production and application of the bio-derived scaffold in the tissue engineered peripheral nerve. Methods The recent articles were systematically analyzed, and then the production methods of the bio-derived scaffold and its application to the tissue engineered peripheral nerve were evaluated and prospected. Results B iological tissues were processed by some methods to produce the bio-derived materials. These mat erials could maintain the structure and components of the tissues. Moreover, the immunogenicity of these materials was reduced. Conclusion Application of the bio-derived materials is a trend in the fabricating scaffold of the tissue en gineered peripheral nerve.
Objective To observe the revascularization process of chemically extracted acellular allogeneous nerve graft in repairing rat sciatic nerve defect. Methods Eighty adult male SD rats were selected. The sciatic nerve trunks from ischial tuberosity to the ramus of tibiofibular nerve of 16 SD rats were obtained and were prepared into acellular nerve stents by chemical reagent. Sixty-four SD rats were used to prepare the models of sciatic nerve defect (1.0 cm) and thereafter were randomized into two groups (n=32): experimental group in which acellular allogeneous nerve grafts were adopted and control group in which orthotopic transplantation of autologous nerve grafts were adopted. Postoperatively, the general conditions of all rats were observed, and the gross and ALP staining observation were conducted at 5, 7, 10, 14, 21, 28 days and 2, 3 months, respectively. Results All the incisions were healed by first intention. Trail ing status and toe’s dysfunction in extension happened to the right hindl imb of rats in two groups and were improved 6 weeks after operation. General observation showed that the grafts of two groups connected well to the nerves, with appearances similar to that of normal nerve. ALP staining demonstrated that the experimental group had no ingrowth of microvessel but the control group had ingrowth of microvessel 5 days after operation; the experimental group had ingrowth of microvessel but both groups had no microvessel 7 days after operation; few longitudinal microvessel throughout the grafts were observed in both groups 10, 14 and 21 days after operation; no obvious difference in capillary network of grafts was observed between two groups 28 days after operation; and the microvascular architecture of grafts in both groups were similar to that of normal nerve 2 and 3 months after operation. Conclusion When the chemically extracted allogeneous nerve graft is adopted to repair the peripheral nerve defect, new blood microvessels can grow into grafts timely and effectively.
Abstract This experiment was to study the feasibility from direct observation of muscle contraction of the lower extremity fromelectrical stimulation threshold of nerve fascicle in identifying the Iα intrafusal afferent fibers during selective posterior rhizotomy (SPR) and to investigate the clinical relationship between the muscle spasm and the electrical stimulation of nerve fascicles. The electrical stimulation threshold of all nerve fascicles in 36 cases during SPR were analysed statistically. The results showed that there was a significant difference between the electrical stimulation threshold of the severed nerve fascicles and intact nerve fascicles no matter the nerve root or each posterior nerve rootlet was examined. It was simple and reliable for surgeons to identify correctly the Iα intrafusal afferent fibers intraoperatively from direct observation of the electrical stimulation threshold of nerve fascicle.
Objective To explore the histochemical staining for distinguishing and local izing nerve fibers and fascicles at histological level in three-dimensional reconstruction of peri pheral nerves. Methods The right median nerve was harvested from one fresh cadaver and embedded in OCT compound. The sample was serially horizontally sl iced with 6 μm thickness. All sections were stained with Karnovsky-Roots method (group A, n=30) firstly and then stained with toluidine blue (group B, =28) and Ponceau 2R (group C, n=21) in proper sequence. The results of each step were taken photos (× 100). After successfully stitching, the two-dimensional panorama images were compared, including texture feature, the number and aver gray level of area showing acetylchol inesterase (AchE) activity, and result of auto microscopic medical image segmentation. Results In groups A, B, and C, the number of AchE-positive area was (21.63 ± 4.06)× 102, (20.64 ± 3.51)× 102, and (20.54 ± 5.71)× 102, respectively, showing no significant difference among 3 groups (F=0.64, P=0.54); the mean gray level was (1.41 ± 0.06)× 102, (1.10 ± 0.05)× 102, and (1.14 ± 0.07)× 102, respectively, showing significant differences between group A and groups B and C (P lt; 0.001). In the image of group A, only AchE-positive area was stained; in the image of group B, myelin sheath was obscure; and in the image of group C, axons and myelin sheath could be indentified, the character of nerve fibers could be distinguished clearly and accurately, and the image segmentation of fascicles could be achieved easier than other 2 images. Conclusion The image of Karnovsky-Roots-toluidine blue-Ponceau 2R staining has no effect on the AchE-positive area in the image of Karnovsky-Roots staining and shows better texture feature. This improved histochemical process may provide ideal image for the three-dimensional reconstruction of peri pheral nerves.
Objective To explore and solve the key technologies of the three dimensional (3D) visual ization reconstruction of functional fascicular groups inside long segmented peri pheral nerve. Methods A 20 cm ulnar nerve from upper arm of fresh adult dead body was embedded by OCT with four pieces of woman’s hair which was used as locating material, then the samples were serially horizontally sl iced into 400 sl ices with 15 μm thickness and 0.5 mm interval. All sl iceswere stained with acetylcholinesterase (AchE) histochemical staining. After that, the 2D panorama images of the same sl ice were obtained with Olympus stereomicroscope and MSHOT MD90 micro figure image device before and after AchE staining. Using the layer processing technique of Photoshop image processing software, the recomposition images including complete 4 location pots were obtained, based on which the algorithm of optimized least square support vector machine (Optimized LS-SVM) and space transformation method was used to fulfill automatic registration. Finally, with artificial assistant outline obtaining, the 3D visual ization reconstruction model of functional fascicular groups of 20 cm ulnar nerve was made using Amira 4.1, and the effects of reverse reduction and the suitabil ity of 3D reconstruction software were evaluated. Results The two-time imaging technique based on the layer process of Photoshop image processing software had the advantages: the image outline had high goodness of fit; the locating pots of merging image was accurate; and the whole procedure was simple and fast. The algorithm of Optimized LS-SVM had high degree of accuracy, and the error rate was only 8.250%. The 3D reconstruction could display the changes of the chiastopic fusion of different nerve functional fascicular groups directly. It could extract alone, merge and combine arbitrarily, and revolve at any angles. Furthermore, the reverse reduction on arbitrarily level dissection of the 3D model was very accurately. Conclusion Based on the two-time imaging technique and computer image layer processing technology, the compute algorithm of auto-registration can be developed and appl ied to 3D visual ization reconstruction of long segmented peripheral nerve. The technological processes is fast, and the reconstruction effect is good.
Objective To investigate the feasibil ity of building the 3D reconstruction of short segment common peroneal nerve functional fascicles based on serial histological sections and computer technology. Methods Five cm of the common peroneal nerve in the popl iteal fossa, donated by an adult, was made into the serial transverse freezing sections(n=200) at an interval of 0.25 mm and 10 μm in thickness per section. Acetylchol inesterase staining was adopted and the nerve fascicles were observed by microscope. 2D panorama images were acquired by high-resolution digital camera under microscope (× 100) and mosaic software. Different functional fascicles were distinguished and marked on each section. The topographic database was matched by image processing software. The 3D microstructure of the fascicular groups of 5 cm common peroneal nerve was reconstructed using Amira 3.1 3D reconstruction software. Results Based on microanatomy and the results of acetylchol inesterase staining, this segmented common peroneal nerve functional fascicles was divided into sensory tract, motor tract, mixed tract and motor-predominating mixed tract. The cross merging was not evident in the nerve fascicles between deep peroneal nerve and superficial peroneal nerve, but existed within the functional fascicles of the deep peroneal nerve and the superficial peroneal nerve. The results of 3D reconstruction reflected the 3D structure of peripheral nerve and its interior functional fascicles factually, which displayed solely or in combination at arbitrary angles. Conclusion Based on serial histological sections and computer technology, the 3D microstructure of short-segment peripheral nerve functional fascicles can be reconstructed satisfactorily, indicating the feasibil ity of building 3D reconstruction of long-segmental peripheral nerve functional fascicles.
Objective To evaluate the value of MRI in diagnosis of obstetrical brachial plexus palsy pre-gangl ionic injury. Methods From November 2006 to February 2008, 10 patients with obstetrical brachial plexus palsy were treated, 8 males and 2 females, aged from 2 months to 3 years (11.4 months on average). There were 7 cases of left side and 3 of right side.According to Tassin classification, 2 cases were type II, 6 type III and 2 type IV. All patients were performed MRI examinations before the operation, whose results were compared with those of exploration during the operation. Results MRI examinations showed 1 patient was normal and 9 patients had post-traumatic spinalmeningolcele. The 6 patients had displacement of spinal cord (4 towards the healthy side and 2 towards the sick side), 6 had deformity of spinal cord, and 2 had avulsed nerve root thickening. MRI detected 19 nerve roots were positive, 16 were true positive and 3 false positive in surgical exploration. MRI detected 6 nerve roots were negative, 4 were true negative and 2 false negative in surgical exploration. The sensitivity, specificity and accuracy of MRI in diagnosis of obstetrical brachial plexus palsy pre-gangl ionic injury were 84.2%, 80.0% and 83.3%, respectively. There were significant differences in the results by preoperative MRI examinations and by exploration during the operation (P lt; 0.05). Conclusion MRI can show pre-gangl ionic injury of brachial plexus of the patients with obstetrical brachial plexus palsy and can supply references for early diagnosis and operation time. MRI can be routinely conducted as a preoperative examination.
ObjectiveTo validate the use of key point matrix technology based contactless automatic measurement for evaluation of joint motion of hand. Methods Thirty-three volunteers were enrolled to evaluate the extension and flexion of hand joints between May 2021 and November 2021. There were 20 males and 13 females, the age ranged from 16 to 70 years with an average of 30.2 years. The extension angles of 14 joints of 5 fingers (including hyperextension) and the flexion angles of 12 joints of 4 fingers (excluding thumb) of volunteers were measured by key point matrix technology and manual goniometer, respectively. Then 5 participants and repeated measurement experiment were employed to test the system repeatability and accuracy; 28 participants and paired measurement experiment were employed to test the system accuracy. Results The average repeatability of finger joint motion measured by the key point matrix technology was 1.801° (extension) and 7.823° (flexion), respectively. Compared with manual measurement, the average differences of each finger joint measured by the key point matrix technology were 3.225° in extension and 14.145° in flexion, respectively. The key point matrix technology based contactless automatic evaluation system offered excellent consistency with the manual goniometers (ICC=0.875). While most of the consistency with manual goniometer of individual joints were at moderate levels (median of ICC, 0.440). The correlation coefficients between the measurement results of the two methods were mainly positive in the extension of the joint (P<0.05) and negative in the flexion of the joints (P<0.05). ConclusionThe key point matrix technology based contactless automatic evaluation provides sufficient measurement repeatability and accuracy in evaluation for the joint motion of hand.