Endoscopic Spinal Surgery for Herniated Lumbar Discs

OBJECTIVE: So called "minimally invasive procedures" have evolved from chemonucleolysis, automated percutaneous discectomy, arthroscopic microdiscectomy that are mainly working within the confines of intradiscal space to transforaminal endoscopic technique to remove herniated epidural disc materials directly. The purpose of this study is to assess the result of endoscopic spinal surgery and favorable indications in the thoracolumbar spine. METHODS: The records of 71 patients, 73 endoscopic procedures, were retrospectively analysed. Yeung Endoscopic Spine Surgery system with 7 mm working sleeve and 25degrees viewing angle was used. The mean follow up period was 6 months (range,3-9). RESULTS: Operated levels were from T12-L1 disc down to L5-L6 or S1 disc. Of 71 cases, 2 patients underwent transforaminal endoscopic surgery twice due to recurrence after initial operation. MacNab's criteria was used to assess the outcome. Favorable outcome, excellent or good, was seen in 78% (57 procedures) of the patients. Among 11 fair outcomes, only 1 procedure was followed by secondary open procedure, laminectomy with discectomy. Two of 5 poor outcomes were operated again by same procedure which resulted in fair outcomes. One patient with aggravated cauda equina syndrome remained poor and a lumbar fusion procedure was performed in other patient with poor outcome. There were 2 postoperative discitis that were treated with conservative care in one and anterior lumbar interbody fusion in the other. CONCLUSION: Evolving technology of mechanical, visual instrument enables minimal invasive procedure possible and effective. The transforaminal endoscopic spinal surgery can reach as high as T12-L1 disc level. The rate of favorable outcome is mid-range among reported endoscopic lumbar surgery series. Authors believe that the outcome will be better as cases accumulate and will be able to reach the rate of standard open microsurgery.

A study on the applicability of polymer(polyglactin)for the artificial dermis

The result of artificial skins made with collagen is poor after grafting over the full thickness wounds due to their rapid degradation by enzymatic cleavage. This study is an in vivo study of an artificial skin made with a biodegradable polymer, which can better address the problem of the collagenous artificial dermis. To investigate the availability of a biodegradable polymer for an artificial dermis and to get an information about the optimal degradation rate of a polymer for an artificial dermis, we made an artificial dermis by seeding of fibroblasts within the vicryl mesh and made a bilayer artificial skin by covering the artificial dermis with cultured keratinocytes. And these artificial dermis and artificial skin were evaluated in a full thickness wound model. The results are as followings: 1. The artificial dermis was available for grafting for 1 week culture of vicryl mesh-fibroblast. 2. The artificial dermis retarded the contraction of full thickness wounds. 3. The artificial dermis generated the granulation tissue and accepted the STSG completely. 4. The generated tissue from the artificial dermis had incorporated into the surrounding tissue by 4 weeks postgrafting. 5. Vicryl in the artificial dermis became to biodegrade from the culture period and absorbed completely by 5 weeks. 6. The epidermal portion was poorly differntiated during in vitro culture period. In conclusion, the polymer-fibroblast graft can retard the wound contraction and generate a new tissue permitting a useful dermal replacement. And to get more optimal results, another polymer which has slower biodegradation rate than vicryl should be used for the artificial dermis and the epidermal portion should be differentiated after in vivo grafting.

Craniofacial growth following unilateral lambdoid synostosis in rabbits

Immobilization of unilateral (right) lambdoid suture was produced in 9-day-old rabbits to determine its effect on subsequent craniofacial growth. The suture was immobilized by the topical application of methyl-2-cyanoacrylate adhesive, subsequent growth effects on the cranial vault, cranial base and facial skeleton were assessed by serial radiographic cephalometry. The statistically significant result(p < 0.05) were: 1. The growth of immobilized lambdoid suture was decreased accompanying compensatory growth at coronal suture bilaterally. 2. The length of anterior and posterior cranial base was increased. 3. Anterior midfacial height was increased. 4. Lower midfacial angle (angular relationship of cranial base to lower midface) was decreased. With the view of above findings, it is clear that restricted growth was seen at unilateral lambdoid suture accompanying compensatory growth at coronal suture and resulted in altered cranial base and facial growth.

A study on the clinical improvement according to the fracture sites pure blow-out fracture

As the traffic accidents and occupational accidents increase, the pure blow out fracture has been increased. If we could know the prognostic information of the pure blowout fracture according to the fracture sites, it would be of benefit in consulting the patients preoperatively and in planning the treatment. In this study we defined the posterior wall fracture as that extending 2 cm from orbital rim and the anterior wall fracture as that presenting within 2 cm from orbital rim. These fractures were individually classified into inferior wall fractures, medial wall fractures, and combined inferior and medial wall fractures, based on the operative finding and the preoperative CT scanning. We experienced 76 cases of pure blowout fracture patients underwent surgical correction and followed up the subsidence of diplopia and extraocular muscle limitation with ophthalmic Hess test. The results obtained are as following: 1. Posterior wall fractures were improved more slowly than anterior wall fractures. 2. Combined inferior and medial wall fractures were improved more slowly than isolate inferior wall or medial wall fractures. These results may be related to the difference of the traumatic forces and the anatomical structure of the fracture sites. These results inform the importance of accurate anatomical reconstruction of fracture sites and can be used as a prognostic information of the pure blow out fractures.

Clinical Experiences in Radiofrequency Catheter Ablation / 대한내과학회지

OBJECTIVES: Among the current therapeutic options for paroxysmal supraventricular tachycardias, only surgery and ablative techniques are curative. However, surgery is associated with substantial cost, morbidity, and rarely death. Recently, catheter ablation techniques have been developed to treat paroxysmal supraventricular tachycardias. These techniques are effective and low-risk curative treatment for supraventricular tachycardias. This article shall describe our clinical experiences in radiofrequency catheter ablation for supraventricular tachycardias and review the literature. METHODS: The study population consisted of 154 patients with supraventricular tachycardias from January 1993 to August 1995. Eighty one patients were men and seventy three patients were women, and their mean age was 41.29 +/- 15.41 years. Radio-frequency currents(mean) were applied through a catheter electrode positioned against the mitral or tricuspid annulus or a branch of the coronary sinus or atrioventricular node. RESULTS: Among 154 patients, the mechanisms for paroxysmal supraventricular tachycardias were found to be atrioventricular reentrant tachycardia involving a concealed accessory pathway in 51(33.1%), Wolff-Parkinson-White syndrome in 57(37%), and atrioventricular nodal reentrant tachycardia in 46 (29.9%). Successful outcomes were achieved in 46 of 46 patients(100%) with atrioventricular nodal reentrant tachycardia, 7 of 8 patients(87.5%) with double accessory pathways, 69 of 72 patients(95.8%) with left-sided accessory pathway, and 19 of 28 patients (67.9%) with right-sided accessory pathway. Total 141 of 154 patients(91.6%) with supraventricular had a successful outcome with radio-frequency current application(mean). CONCLUSIONS: Radiofrequency catheter ablation techniques are highly effective in ablating accessory pathways or modifying atrioventricular node, with low morbidity and no mortality.

The Tissue Damage due to Radiofrequency Energy in Bovine Skeletal Muscle

BACKGROUND: Radiofrequency(RF) catheter ablation has rapidly emerged as the treatment of choice for symptomatic reentrant arrythmia associated with accessory pathway or atrioventricular node conduction. Rarely RF catheter ablation therapy can produce the cardiac perforation, ventricular function insufficiency and arrythmia. So, the purpose of this study was to determine the correlation between the RF energy and muscle injury. METHODS: Bovine skeletal muscle was immersed in normal saline, and the entire chamber was heated to 36-37degrees C by water bath. The 4mm tip 7 Fr electrode catheter was placed horizontally on the skeletal muscle surface withoup pressure. RF energy was delicered to tissue for the pulse duration of 10, 20, 30, 40, 50, 60 seconds and voltage of 10, 15, 20, 25, 30, 35, 40, 45volt and total 432 lesions were produced. Horizontal, vertical lesion diameters and depths were measured, and the area and volume of lesion were calculated. RESULTS: Increasing voltage and duration of RF increased the horizontal and vertical diameter, depth, area and volume of lesion(p<0.0001). The RF pulse duration and voltages made lesion below 5mm depth were 45volt applied dbelow 20seconds, 40volt applied below 25seconds, 35volt applied below 32seconds, 30volt applied below 38seconds, 25volt applied during any duation of time. CONCLUSION: So, for prevention of undesirable tissue damage, the adequate pulse duration and voltage of RF must to be delivered to tissue.

Evaluation of Myocardial Injury after Radiofrequency Catheter Ablation for Supraventricular Tachycardia by Means of Measurement of Myocardial Enzyme

OBJECTIVES: Radiofrequency(RF) ablation is an effective and low risk curative treatment for supraventricular arrhythmias. Catheter ablation produced cardiac lesions primarily through formation of coagulation necrosis. We evaluated the degree of myocardial injury after RF catheter ablation by means of serial measurement of myocardial enzyme. METHODS: Fifty-one patients with symptomatic supraventricular tachycardia were included. There were 32 men and 19 women(mean age. 39.5+/-15.4 years)All patients underwent electrophysiologic study to detect accessary pathway and ablation with radiofreguency current. A mean of 18.3+/-14.2 radiofrequency pulses were delivered. The pulses were at a power of 50 to 60 Volts for a duration of 20 to 30 seconds. Unipolar method and a 6F or 7F catheter with a 4 mm tip electrode was used. LDH, CPK and Ck-MB as a kind of cardiac enzyme were measured before and after ablation. RESULTS: 1) The concentration of LDH and CPK were elecated at 8 hours and 16 hours after ablation (p<0.05). 2) The concentration of CK-MB was elevated at 8 hours, 16 hours, 24 hours and 72 hours after ablation(p<0.05). 3) There was no correlation between the number of applications and amounts of radiofrequency current and rise in LDH, CPK, CK-MB concentration. CONCLUSION: The concentration of LDH, CPK and CK-MB were elevated after ablation but they were within normal limits. RF catheter ablation produced myocardial damage inevitably but were within normal limits. RF catheter ablation produced myocardial damage inevitably but minimally, then RF ablation is an effective and safe therapeutic modality for patients with symptomatic tachyarrhythmias.

A Case of Huge Left Ventricular Thrombus Associated with Hypereosinophilic Syndrome

Cardiac manifestations of hypereosinophilic syndrome rarely include left ventricular thrombosis leading to peripheral emboli. And the cases of thrombectomy in patients with left ventricular thrombus and hypereosinophilic syndrome are extremely rare. Recently we experienced a 58-years-old woman with hypereosinophilic syndrome, the history of thalamic infarction and a huge thrombi in left ventricle. We report this case with literatures.