• Archives of Plastic Surgery
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• v.34 no.3
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• pp.279-284
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• 2007

Purpose: The vein graft was considered as a useful conduit for nerve defect. But the problem is that it might be collapsed in long vein graft state. A new experimental model using vein graft filled with hyaluronic acid was considered. Methods: Thirty rats were used for the experimental animal. In group I, one side of the femoral nerve was exposed and a segment was removed about 15mm. The neural gap was connected with nerve graft. In group II, the nerve gap was connected with vein graft only. In group III, the nerve gap was connected with vein graft filled with hyaluronic acid. A walking track analysis was made periodically for 2 months and NCV(nerve conduction velocity) was executed at the end of the experiment. And morphologic studies were also done for all groups Results: In a walking track analysis, the toe-spread was widen and the foot-length was lengthened. The recovery of the toe-spread and foot length was checked 2 weeks interval, periodically for two months. The SFI (sciatic function index) was $-52.5{\pm}8.2$ in group I, $-68.1{\pm}4$ in group II, $-55.3{\pm}7.9$ in group III. In electrophysiological study, NCV(nerve conduction velocity) was $26.71{\pm}3.11m/s$ in group I, $17.94{\pm}4.35m/s$ in group II, $25.69{\pm}2.81m/s$ in group III. The functional recovery in group I and III was superior to that the group II statistically(p < 0.05) Under electromicroscopic study, the number of the myelinated axons were $1419.1{\pm}240$ in group I, $921.7{\pm}176.8$ in group II, $1322.2{\pm}318$ in group III. The number of the myelinated axons were much more in group I and III than group II statistically (p<0.05). Conclusion: This study suggested that the vein graft filled with hyaluronic acid is more effective than vein graft only for the conduit of the nerve gap. It was thought that the technique could be used in clinical cases with nerve defects as an alternative method to classical nerve grafts.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.6
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• pp.465-473
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• 2004

Purpose : The essential triad for nerve regeneration is nerve conduit, supporting cell and neurotrophic factor. In order to improve the peripheral nerve regeneration, we used polyglycolic acid(PGA) tube and brain-derived neurotrophic factor(BDNF) gene transfected Schwann cells in sciatic nerve defects of SD rat. Materials and methods : Nerve conduits were made with PGA sheet and outer surface was coated with poly(lactic-co-glycolic acid) for mechanical strength and control the resorption rate. The diameter of conduit was 1.8mm and the length was 17mm Schwann cells were harvested from dorsal root ganglion(DRG) of SD rat aged 1 day. Schwann cells were cultured on the PGA sheet to test the biocompatibility adhesion of Schwann cell. Human BDNF gene was obtained from cDNA library and amplified using PCR. BDNF gene was inserted into E1 deleted region of adenovirus shuttle vector, pAACCMVpARS. BDNF-adenovirus was multiplied in 293 cells and purified. The BDNF-Adenovirus was then infected to the cultured Schwann cells. Left sciatic nerve of SD rat (250g weighing) was exposed and 14mm defects were made. After bridging the defect with PGA conduit, culture medium(MEM), Schwann cells or BDNF-Adenovirus infected Schwann cells were injected into the lumen of conduit, respectively. 12 weeks after operation, gait analysis for sciatic function index, electrophysiology and histomorphometry was performed. Results : Cultured Schwann cells were well adhered to PGA sheet. Sciatic index of BDNF transfected group was $-53.66{\pm}13.43$ which was the best among three groups. The threshold of compound action potential was between 800 to $1000{\mu}A$ in experimental groups which is about 10 times higher than normal sciatic nerve. Conduction velocity and peak voltage of action potential of BDNF group was the highest among experimental groups. The myelin thickness and axonal density of BDNF group was significantly greater than the other groups. Conclusion : BDNF gene transfected Schwann cells could regenerate the sciatic nerve gap(14mm) of rat successfully.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.2
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• pp.261-268
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• 1996

An experimental study was performed to evaluate the efficacy of nerve growth factor(NGF) on inferior alveolar nerve in a rabbit model. In 20 New Zealand white rabbits, 14mm of bilat eral alveolar nerve were resected and the defects were repaired with the 17mm silicone conduits. In group I, 5mm autologous nerve segment were located centrally in the left side after tubulization and NGF solution(Sigma chemical 0.1 mg/mL) was instilled into each conduit. In group II, nerve repair modality was the same but no NGF solution was instilled into the conduits. On 2 months and 6 months postoperatively, the results were evaluated by clinical and hist omorphometric assessment. The result was that autologous nerve segment group show the best nerve regeneration effect and NGF instilled group the worst.

• 대한미세수술학회:학술대회논문집
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• 1997.10a
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• pp.121.1-121.1
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• 1997

• Archives of Plastic Surgery
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• v.33 no.2
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• pp.213-218
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• 2006

As the large defect of peripheral nerve occurs, the autologous nerve graft is the most ideal method but it has many limitations due to donor site morbidities. Various materials have been developed for the nerve defect as the conduits, but none of these materials is satisfactory. Among them, $Gore-Tex^{(R)}$ tube seems to be one of the most ideal nerve conduit materials at peripheral nerve defect. Many researches have focused on finding the neurotrophic factors. It is recently demonstrated that Valproic acid(VPA) has an effect of axonal regeneration as a neurotrophic factor without enzymatic degradation and toxicity problems. The purpose of this study is to evaluate the effect of VPA on the nerve regeneration at the peripheral nerve defect. A 10 mm gap of rat sciatic nerve was made and $Gore-Tex^{(R)}$ tube filled with biceps femoris muscle was placed at the nerve defect site. We let the rat take VPA as drinking water in experimental group and did not give VPA to the control group. We estimated the results as electrophysiologic and histological aspects for 16 weeks after the surgery. The nerve conduction velocity, total myelinated axon count, myelin sheath thickness and mean nerve fiber diameter significantly increased in VPA-treated experimental group when compared to the control (p < 0.05). From the above results, we conclude that VPA promotes the nerve regeneration at the peripheral nerve defect site. It is suggested that $Gore-Tex^{(R)}$ tube filled with skeletal muscle and VPA administration may be a good substitute for autologous nerve graft.

• Polymer(Korea)
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• v.25 no.6
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• pp.893-901
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• 2001

We developed the nerve growth factor (NGF) loaded poly (L - lactide) (PLA) scaffolds by means of emulsion freeze drying method to the possibility for the application of the nerve regeneration of spinal cord disease and the degeneration in Alzheimer's disease. The release amount of NGF from NGF loaded PLA scaffold were analyzed over a 4 week period in vitro at phosphate buffered saline (PBS), pH 7.4, at $37^{\circ}C$. It can be observed the open cell pore structure of porous scaffolds and can be easily controlled the pore structure by the controlling of formulation factors resulting in the controlling of the release rate and the release period. The stability of NGF during the preparation of PLA scaffold was evaluated by comparing the released amounts of total NGF, assayed NGF enzyme - linked immunosorbent assay (ELISA). Released NGF has been found to enhance the neurite sprouting and outgrowth from pheochromocytoma (PC-12) cells. These results suggest that the released NGF from NGF loaded PLA scaffold such as conduit type can be very useful for the nerve regeneration in the neural tissue engineering area.

• Archives of Reconstructive Microsurgery
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• v.6 no.1
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• pp.29-38
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• 1997

A peripheral nerve when approximation of the ends imparts tension at the anastomosis and with a relatively long segment defect after excision of neuroma and neurofibroma cannnot be repaired by early primary suture. The one of the optimistic reconstruction method of severed peripheral nerves is to restore tension-free continuity at the repair site putting an autogenous nerve graft into the neural gap despite of ancipating motor or sensory deficit of the donor nerve area. To overcome the deficit of the autogenous nerve graft, several other conduits supplying a metabolically active environment which is able to support axon regeneration and progression, providing protection against scar invasion, and guiding the regrowing axons to the distal stump of the nerve have been studied. An author have used ipsilateral femoral vein, ipsilateral femoral vein filled with fresh thigh muscle, and autogenous sciatic nerve for the sciatic nerve defect of around 10 mm in length to observe the regeneration pattern in rat by light and electron microscopy. The results were as follows. 1. Light microscopically regeneration pattern of nerve fibers in the autogenous graft group was more abundant than vein graft and vein filled with muscle group. 2. On ultrastructural findings, the proxial end of the graft in various groups showed similar regenerating features of the axons, myelin sheaths, and Schwann cells. The fascicular arrangement of the myelinated and unmyelinated fibers was same regardless of the type of conduits. There were more or less increasing tendency in the number and the diameter of myelinated fibers correlated with the regeneration time. 3. In the middle of the graft, myelinated nerve fibers of vein filled with muscle group were more in number and myelin sheath was thinner than in the venous graft, but the number of regenerating axons in autogenous nerve graft was superior to that in both groups of the graft. The amount of collagen fibrils and amorphous materials in the endoneurial space was increased to elapsed time. 4. There was no difference in regenerating patterns of the nerve fibers of distal end of the graft. The size and shape of the myelinated nerve fbers were more different than that of proximal and middle portion of the graft. From the above results, the degree of myelination and regenerating activity in autogenous nerve is more effective and active in other types of the graft and there were no morphological differences in either ends of the graft regardless of regeneration time.

• Journal of Chest Surgery
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• v.46 no.3
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• pp.165-177
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• 2013

This is the third in a series on coronary artery bypass which reviews three alternative arterial conduits. The radial artery has become the most widely used of the three and accumulating experience demonstrates better patency at 10 years versus saphenous vein. Drawbacks are a long incision on the forearm, the propensity for spasm and persistent sensory disturbance in about 10%. The first is answered by endoscopic harvest which may yield a shorter conduit but reduces sensory nerve injury. Spasm is managed pharmacologically and by less harvest trauma. The gastroepiploic artery is used in situ and free and although the abdominal cavity is entered complications are minimal and patency compares favorably with the radial artery. Use of the inferior epigastric artery remains minimal and its similar length often requires composite use but limited patency data are supportive. Other arteries have had rare use and this is unlikely to change because the three presented here have significant advantages and acceptance.

• Journal of Chest Surgery
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• v.28 no.1
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• pp.65-68
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• 1995

Pectus excavatum occasionally occurs in patients who have underlying cardiac disease, especially Marfan syndrome. This report describes a patient with pectus excavatum who had ascending aortic aneurysm with aortic regurgitation and anterior leaflet prolapse of mitral valve. This patient underwent replacement of aortic valve and ascending aorta with 25 mm SJM valved conduit graft[Bentall operation with Cabrol shunt , and mitral valve replacement with SJM 31 mm, the pectus excavatum was corrected at the time of completion of the intracardiac operation with the modified sternal turnover. This procedure offered excellent operative exposure for the inracardiac operation with prevention of low cardiac output after operation due to depressed sternum and maintained chest wall stability resulting good cosmetic chest wall appearance. This patient recovered and discharged in good postoperative result with minimal temporary peroneal nerve palsy in his left leg.

• Journal of Chest Surgery
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• v.53 no.4
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• pp.233-241
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• 2020

Vagal damage and subsequent pyloric denervation inevitably occur during esophagectomy, potentially leading to delayed gastric emptying (DGE). The choice of an optimal pyloric procedure to overcome DGE is important, as such procedures can lead to prolonged surgery, shortening of the conduit, disruption of the blood supply, and gastric dumping/bile reflux. This study investigated various pyloric methods and analyzed comparative studies in order to determine the optimal pyloric procedure. Surgical procedures for the pylorus include pyloromyotomy, pyloroplasty, or digital fracture. Botulinum toxin injection, endoscopic balloon dilatation, and erythromycin are non-surgical procedures. The scope, technique, and effects of these procedures are changing due to advances in minimally invasive surgery and postoperative interventions. Some comparative studies have shown that pyloric procedures are helpful for DGE, while others have argued that it is difficult to reach an objective conclusion because of the variety of definitions of DGE and evaluation methods. In conclusion, recent advances in interventional technology and minimally invasive surgery have led to questions regarding the practice of pyloric procedures. However, many clinicians still perform them and they are at least somewhat effective. To provide guidance on the optimal pyloric procedure, DGE should first be defined clearly, and a large-scale study with an objective evaluation method will then be required.