A New Experimental Model of Heterotopic Intrathoracic Heart Transplantation without Cardiopulmonary Bypass

BACKGROUND AND OBJECTIVES: A variety of experimental heterotopic heart transplantation models have been developed for the purpose of this study. However most were complicated and used extracorporeal circulation. A new and simple experimental working heterotopic intrathoracic heart transplantation model has been developed in dogs, which could be performed without support of extracorporeal circulation. MATERIALS AND METHODS: Six mongrel dogs were used for the three heterotopic heart transplantation experiments. The heterotopic hearts were transplanted in the right thoracic cavity using a right thoracotomy. The superior vena cava and left atrial cuff of the donor heart was anastomosed to the superior vena cava and left atrium of the recipient heart. Consequently, the aorta and pulmonary artery were anastomosed to the ascending aorta and right atrial appendage of the recipient heart, without cardiopulmonary bypass. The electrocardiograms of the donor and recipient hearts were measured by electrodes placed at the ventricular apexes and on the skin. RESULTS: The donor hearts survived for 10, 6 and 18 days after transplantation, without any immunosuppressive agents or anticoagulants. The electrocardiograms of both hearts could be measured using the electrodes. There were no wave or voltage changes on electrocardiography. CONCLUSION: This working heart model of heterotopic intrathoracic transplantation, without cardiopulmonary bypass, may be useful in studies for various purposes, i.e., the effects of different pharmacological agents on the conduction system of the denervated heart and the hemodynamic changes of the recipient with auxiliary support of the transplanted heart.

Application of a Single-pulsatile Extracorporeal Life Support System for Extracorporeal Membrane Oxygenation: An experimental study / 대한흉부외과학회지

BACKGROUND: Extracorporeal life support (ECLS) system is a device for respiratory and/or heart failure treatment, and there have been many trials for development and clinical application in the world. Currently, a non-pulsatile blood pump is a standard for ECLS system. Although a pulsatile blood pump is advantageous in physiologic aspects, high pressure generated in the circuits and resultant blood cell trauma remain major concerns which make one reluctant to use a pulsatile blood pump in artificial lung circuits containing a membrane oxygenator. The study was designed to evaluate the hypothesis that placement of a pressure-relieving compliance chamber between a pulsatile pump and a membrane oxygenator might reduce the above mentioned side effects while providing physiologic pulsatile blood flow. MATERIAL AND METHOD: The study was performed in a canine model of oleic acid induced acute lung injury (N=16). The animals were divided into three groups according to the type of pump used and the presence of the compliance chamber. In group 1, a non-pulsatile centrifugal pump was used as a control (n=6). In group 2 (n=4), a single-pulsatile pump was used. In group 3 (n=6), a single-pulsatile pump equipped with a compliance chamber was used. The experimental model was a partial bypass between the right atrium and the aorta at a pump flow of 1.8~2 L/min for 2 hours. The observed parameters were focused on hemodynamic changes, intra-circuit pressure, laboratory studies for blood profile, and the effect on blood cell trauma. RESULT: In hemodynamics, the pulsatile group II & III generated higher arterial pulse pressure (47+/-10 and 41+/-9 mmHg) than the nonpulsatile group I (17+/-7 mmHg, p<0.001). The intra-circuit pressure at membrane oxygenator were 222+/-8 mmHg in group 1, 739+/-35 mmHg in group 2, and 470+/-17 mmHg in group 3 (p<0.001). At 2 hour bypass, arterial oxygen partial pressures were significantly higher in the pulsatile group 2 & 3 than in the non-pulsatile group 1 (77+/-41 mmHg in group 1, 96+/-48 mmHg in group 2, and 97+/-25 mmHg in group 3; p<0.05). The levels of plasma free hemoglobin which was an indicator of blood cell trauma were lowest in group 1, highest in group 2, and significantly decreased in group 3 (55.7+/-43.3, 162.8+/-113.6, 82.5+/-25.1 mg%, respectively; p<0.05). Other laboratory findings for blood profile were not different. CONCLUSION: The above results imply that the pulsatile blood pump is beneficial in oxygenation while deleterious in the aspects to high pressure generation in the circuits and blood cell trauma. However, when a pressure-relieving compliance chamber is applied between the pulsatile pump and a membrane oxygenator, it can significantly reduce the high circuit pressure and result in low blood cell trauma.

Video Assisted Thoracoscopic Sympathetic Ramus Clipping in Essential Hyperhidrosis: Cadaver Fitting Test and Clinical Application / 대한흉부외과학회지

BACKGROUND: It has been known that the most effective treatment method of hyperhidrosis is video-assisted thoracoscopic sympathetic nerve block. Postoperative compensatory hyperhidrosis and anhidrosis are major factors that decrease the postoperative satisfaction. Although sympathetic rami have been selectively blocked to decrease the complications, technical difficulties and excessive bleeding have prevented the universal application. MATERIAL AND METHOD: Three pre-fixative cadavers were dissected before clinical application. Bilateral sympathetic chains were exposed in supine position after the whole anterior chest wall was removed. Second and third sympathetic rami were blocked using clips. After the sympathetic chains including ganglia were removed, we evaluated the extents of rami block. Twenty-five patients were subjected to the clinical application. Surgeries were performed in semi- fowlers position under general anesthesia and bilateral ventilation. 2 mm thoracoscopy and 5 mm trocar were introduced through third and fourth intercostal space, respectively. Second and third sympathetic rami were blocked using thoracoscopic clips. The postoperative complications, satisfaction, and compensatory hyperhidrosis rate were evaluated retrospectively. RESULT: Sympathetic rami were completely blocked in cadaver dissection study. Hyperhidrosis symptom was improved in all patients without operative complication. Operative time was shorter than that of traditional ramicotomy. All patients, except four, were satisfied with postoperative palmar hyperhidrosis. Compensatory hyperhidrosis was more severely happened in fifteen patients (60%). The remaining six patients had no complaint. Two patients had a minimal degree of gustatory hyperhidrosis. CONCLUSION: This operative method had shorter operative time and less complication rate, compared with traditional ramicotomy. Operative success rate was similar to the traditional sympathicotomy; lower extent and occurrence rate of compensatory hyperhidrosis. The thoracic sympathetic rami clipping was suggested as an alternative method for treatment of palmar hyperhidrosis.

Effectiveness of Esophageal Ultrasonography in Surgical Therapy of Esophageal Cancer / 대한흉부외과학회지

BACKGROUND: With the advent of stage-adapted multimodal regiments for esophageal malignancy, accurate staging has become of utmost importance. Endoscopic ultrasonography(EUS) is a diagnostic method for the local staging of esophageal cancer, in particularfor T and N evaluation. The aim of this study was to examine the diagnostic efficacy of the EUS and to evaluate the relation between prognosis and EUS findings. MATERIAL AND METHOD:We reexamined the cases of 88 consecuitive patients who underwent transthroacic esophagectomy and cervical esophagogastrostomy for esophageal cancer from January 1991 to July 2001. We compared EUS findings, histological results and outcomes. RESULT: There were 83 male(94.3%) and 5 female. Median age was 61.3 years old. Overall staging accuracy were 59.0% for T staging and 76.0% for N staging, In early T staging group, the accuracy was 74.9% except T4 stage. However significant differences were not found in the ability of EUS: determined T stage and N-stage to predict survival. Multivariate analysis showed EUS-stage to predict survival. CONCLUSION: EUS provides a high degree of accuracy in assessing both T and N parameters in staging esophagal cancer. EUS should be performed in all patients with esophageal cancer, not only for staging before therapy, but also as a valuable method of determining prognosis.

Idiopathic Mediastinal Fibrosis (2 case) / 대한흉부외과학회지

Idiopathic mediastinal fibrosis is very rare. We report two cases of a 41-year-old man and 65-year-old man who presented with backache and vocal cord palsy, subsequently confirmed to be idiopathic mediastinal fibrosis. Preoperative chest computed tomography showed a mediastinal mass and oracoscopic biopsy was preformed. The mass was hard, dense and partially calcified, and adhered the adjacent mediastinal structure. Postoperative medical treatment was not performed, and during 5 and 7 month follow-up has not demonstrated any complication.

Cadaver Fitting Test of Mechanical Circulatory Assist Device Including Korean Artificial Heart (AnyHeart) in Korea / 대한해부학회지

Preclinical cadaver fitting study is paramount in the development of various implantable medical devices. It helps to evaluate the fitness of the size, shape, structure of the devices in the human anatomy, to locate the most optimal site for implantation, and to develope the clinically available surgical techniques. The purpose of this study was to observe the anatomical feasibility of Korean artificial heart (AnyHeart) in 12 human cadavers after obtaining the permission from the Korea University Anatomical Research Committee. The observation was focused on proper position of the artificial heart in various thoracic incisions (median sternotomy, right thoracotomy, left thoracotomy, transsternal incision), localization of inflow as well and outflow tract, cannulation sites, and so on. Results showed that Korean artificial heart had excellent anatomical feasibility in the human body and that a novel surgical technique of right thoracotomy approach was proved to be clinically applicable. Conclusively, the above results will provide the rationales of clinical trial and demonstrate the significance of human cadaver study in development of implantable medical devices.

Evaluation of the Potential of Retrograde Flow Competition in the Right Gastroepiploic Artery Graft for Coronary Artery Bypass Grafting / 대한흉부외과학회지

BACKGROUND: Due to the concern of flow competition or retrograde steal, it has been generally suggested that the right gastroepiploic artery(RGEA) pedicled graft should be used in critical coronary stenosis lesion. The study was designed to evaluate the potential of retrograde flow competition in the RGEA pedicled graft by measuring the native pressure differences(PD) between the normal coronary artery and celiac arterial pressure, which would be compared with trans-stenosis pressure gradients(TSPG) in coronary artery occlusive disease. MATERIAL AND METHOD: Between July, 1998 and February, 1999, pressures of the right coronary artery and the right gastroepiploic artery(or the celiac artery) were measured in patients with the patent right coronary artery(n=12). The PD between the arteries was compared with the TSPG in the occlusive coronary arteries(n=32). RESULT: The pressures of the normal right coronary artery and celiac artery were 143+/-23 vs. 134+/-17mmHg in systole(p<0.005), 74+/-13 vs. 73+/-14mmHg in diastole(p=NS), and 100+/-16 vs. 97+/-15mmHg in mean (p0.05). The PD between the arteries were -8~25mmHg in systole, -4~7 mmHg in diastole, and -1~10mmHg in mean. The TSPG measured in the occlusive coronary arteries were -4~19(7+/-5.8)mmHg in the lesion less than 75% stenosis vs. 7~74(27+/-18.3)mmHg in the 75% or over stenosis lesion(p0.005). The normally existing pressure difference between the coronary arteries and RGEA(15~20mmHg) was significantly less than the TSPG in the occlusive coronary artery with 75% or over stenosis(p0.001). CONCLUSION: If the pressure gradient between the RGEA and the coronary artery distal to the stenosis is the main determinant of development of retrograde flow competiton in the RGEA pedicled graft, the above data suggests that there will be little chance of competition when it is used in the coronary lesion with 75% or over stenosis.

Surgical Technique for Korean Artificial Heart(AnyHeart) Implantation Using a Right Thoracotomy Approach / 대한흉부외과학회지

BACKGROUND: The surgical technique for biventricular assist device(BVAD) implantation has mainly consisted of cannulation procedures. A median sternotomy has been the technique of choice as it gives a surgeon an excellent exposure of the heart. However, considering that most patients require a future sternotomy or already have a previous sternotomy, sternotomy-related complication remains a major concern in BVAD implantation. Based on this consideration as well as the clinical experiences of conventional heart surgery, the authors have hypothesized that the cardiac chambers for BVAD cannulation can be approached from the right side of the heart. The purpose of this study to develop a novel surgical technique of right thoracotomy for BVAD implantation in an animal study. MATERIAL AND METHOD: For last two years, 16 (11 calves, 3 canines, and 2 sheep) out of 30 experimental animals with AnyHeart implantation underwent a right thoracotomy. The device was used as an implantable BVAD in 14 animals, a wearable BVAD in 1, and an implantable LVAD in 1. The chest cavity was entered through the 4th intercostal space or the 5th periosteal bed. As for the BVAD use, a right inflow cannula was inserted into the right atrial free wall and a right outflow cannula was grafted onto the main pulmonary artery. A left inflow cannula was inserted into the interatrial groove and a left outflow cannula was grafted on the innominate artery of the ascending aorta. The connecting tubeswere brought out through the thoracotomy wound and connected to the pump located in the subcutaneous pocket at the right flank. RESULT: Except for the 5 animals for a fitting test or during the early learning curve, all recovered smoothly from the procedures. The inflow drainage allowed the pump output 6.5 L/min at the maximum with 3-3.5 L/min in an average. Of the survivors, there noted no procedure-related mortality or morbidity. Necropsy findings demonstrated the well-positioned cannula tips in the each cardiac chamber. CONCLUSION: The technique of right thoracotomy approach in AnyHeart implantation is simple, safe, and reproducible. As it can avoid sternotomy-orresternotomy-related complications, the authors suggest a right thoracotomy approach as one of the techniques for BVAD implantation. The technique would also be suggested as an alternatitve for a median sternotomy in a certain group of patients with various VAD implantations.

A Clinical Experience of Korean Artificial Heart(AnyHeart) / 대한흉부외과학회지

Korean artificial heart(AnyHeart) is a single-pieced and implantable bi-ventricular pulsatile pump adapting a moving actuator mechanism. The authors report a case of clinical application of AnyHeart as a life-saving device for the patients with end-stage heart disease combined with biventricular failure.

Evaluation of Biocompatibility of Extracorporeal Circuit: Development of a Quantification Technique using Invivo Injection of Tc99m Radioactive Platelets / 대한흉부외과학회지

BACKGROUND: Blood-foreign interaction cause activation of coagulation and inflammatory process that may lead to multiorgan dysfunction and determine the surgical outcomes.Of the methods for assessing the biocompatibility,the platelet adhesion study is considered as the most valuable evaluation step in blood-foreign interaction.As the most studies have used in-vitro or ex-vivo conditions,we have developed a technique of quantification for platelet adhesion on the blood contact surface by using in-vivo injection of radioactive platelets. MATERIAL AND METHOD: A coupled bypass circuit was designed to connect the proximal and descending thoracic aorta in 6 piglets(20~25 Kg).One side of the circuit tube was consisted of a heparin coated PVC tube(10mm in ID, n=6, Experimental group),and the other,a non-heparin coated PVC tube(10mm in ID, n=6, Control group).After cannulation,the blood was circulated through the circuit for 2 hours. Platelet concentrate was prepared from homologous pig blood 24 hours before the experiment.The platelet concentrate was incubated with Tc-99m-HMPAO for 30 min and then centrifuged for 10 min.The supernatant was discarded and the radio-labeling efficacy was measured.The radio-labeled platelet concentrate was mixed with the autologous plasma to make the volume 5 ml,and the mixture was injected intravenously into the experimental animal.After 2 hour circulation, 5 pieces of the specimen(10mm in length each)were obtained from each PVC tube.The radioisotopes were counted with a gamma counter(Cobra II,Packard,USA),and the ratio of radioisotope count was compared between the control and experimental group. RESULT: The radioisotope count number was 537.3221.1 Ci/min in the control group and 311.1 184.5 Ci/min in the experimental group(p=0.0104).The ratio between the groups was 1 to 0.58 (p=0.004). CONCLUSION: In vivo quantification using technetium-99m-HMPAO labeled platelets is simple and reproducible in evaluating platelet adhesion on a foreign surface.We suggest this technique to be a useful tool for blood compatibility test.

2mm Video Thoracoscopic Examination for Primary Spontaneous Peumothorax / 대한흉부외과학회지

BACKGROUND: The purpose of this study was to evalute the diagnostic value of 2mm video thoracoscopy for primary spontaneous penumothorax. MATERIAL AND METHOD: During the period of March to June 1999, we prospectively analyzed 33 consecutive patients suffering from primary spontaneous pneumothorax. 2mm video-assisted thoracoscopy was compared with the operative finding. We observed recurrence during the mean follow-up of 3months. RESULT: Blebs were present in 24 patient(73%: 24/33). These were treated by 10mm video-assised thoracoscopic stapling. Nine pateints with no bleb were treated with pleural drainage. There were no significant differences in the bleb finding. No recurrence occurred during the follow-up period. CONCLUSIONS: A 2mm video thoracoscopic examination for primary spontaneous pnumothorax is a useful alternative in deciding the operative indication.

Botulinum A toxin for the treatment of focal hyperhidrosis: 5 cases / 대한흉부외과학회지

Thoracic sympathicotomy has been used safely and successfully to treat essential hyperhidrosis. However, it has been difficult to treat compansatory hyperhidrosis after thoracic sympathicotomy and focal hyperhidrosis. The sweat glands were innervated by post-ganglionic sympathetic fibers with acetylcholic serving as the transmitter. Botulinum A toxin has been reported to block neuro-transmission at the cholinergic autonomic nerve terminals. Prospecting its effect for the sweat gland, we treated 5 patients with focal hyperhidrosis with botulinum A toxin. Three patients received bilateral thoracic sympathectomy (1 case) and sympathicotomy(2 case) via VAT. The hyperhidrosis area was marked with betadine and was subdivided into squares of 2x2 cm(4cm(2)) each. Botulinum A toxin was injected intracutaneously in a dosage of 2.5U/0.1ml(100U/4ml) /4cm(2). A total dose of 100U of Botulinum A toxin was injected into the affected sites. Subjective assessment of sweat production by the patients using a visual analogue scale showed a 20~70% improvement. During the follow-up period, no toxic effects were observed.

Retrievable Nitinol Stent for Treatment of Tuberculous Tracheobronchial Stenosis: A case report / 대한흉부외과학회지

Although a tracheal stent can be an option for inoperable tracheal stenoses there still are some troublesome side effects including overgranulation from foreign body irritation restenosis and patient's discomfort associated with the procedure. We report a successful case of a retrievable stent made of self-expandable 'shape memory' metal and polyurethane in a 24 year old female patient with respiratory distress and tight stenosis in the trachea and left main bronchus, The stent was inserted following a balloon dilatation and was successfully removed on the 7th days after the procedure. She regained a normal active life without any repiratory symptoms and a follow-up of 8 months showed satisfactory results.

Video-Assisted Thoracic Surgery Under Epidural Anesthesia -in High-Risk Group / 대한흉부외과학회지

BACKGROUND: Video-assisted thoracoscopic surgery has become a standard therapy for several diseases such as pneumothorax, hyperhidrosis, mediastinal mass, and so on. These methods usually required single-lung ventilation with double-lumen endobronchial tube to collapse the lung under general anesthesia. However, risks of general anesthesia itself and single-lung ventilation must be considered in high-risk patients. MATERIAL AND METHOD: Between December 1997 and July 1998, eight high-risk patients (6: empyema, 1: intractable pleural effusion, 1: idiopathic pulmonary fibrosis) with underlying pulmonary disease and poor general condition were treated by video-assisted thoracoscopic surgerys under epidural anesthesia and spontaneous breathing. RESULT: Video-assisted thoracoscopic surgerys were successfully per formed in 7 patients. Conversion to general anesthesia was required in 1 patient because of decrease in spontaneous breathing. But, conversion to open decortication was not required. In two patients with chronic empyema, one patient required thoracoplasty as a second procedure and one patient required re-video-assisted thoracoscopic procedure due to a recurrence. The mean operative time was 31.8+/-15.2 minutes. No significant postoperative respiratory com plication was encountered. CONCLUSION: Video-assisted thoracoscopic surgerys can be per formed safely under epidural anesthesia for the treatment of empyema and diagnosis of pulmonary abnormalities in high-risk patients.

Thoracoscopic T-3 Sympathicotomy for Palmar Hyperhidrosis / 대한흉부외과학회지

BACKGROUND: This study was designed to evaluate the effectiveness of T3 sympathicotomy in treatment of palmar hyperhidrosis. MATERIAL AND METHOD: During the period of June to December 1998, 50 patients (24 females and 26 males) suffering from palmar hyperhidrosis either in isolation (n=37) or in combination with axillary hyperhidrosis (n=13) were operated. The mean age of the patients was 20 years. The bilateral sympathetic trunks were severed on the 3rd rib (2nd and 3rd ganglia) for the isolated palmar hyperhidrosis and on the 3rd and 4th ribs for the combined type using electrocoagulation scissors. A linear analogue scale was used to assess the degree of sweating on the palms, face, trunk, and feet (ranged 0 to 10:0 = anhidrosis: 10 = excessive sweating) as well as the patient's satisfaction with the surgery (ranged 0 to 10:0 = regret; 10 = completely satisfied). RESULT: All of the patients were relieved from palmar hyperhidrosis. A mean palmar sweat production score after T3 sympathicotomy was 1.5+/-0.8. Some degree of compensatory sweating had occurred in 39 patients (78%) with a mean score of 3.4+/-1.6. Gustatory sweating occurred in 2 patients (4%). The mean score of the patient's satisfaction after the surgery was 8.5+/-1.2. CONCLUSION: Palmar hyperhidrosis can be successfully relieved by the T3 sympathicotomy. When considering the advantages of T3 sympathicotomy with respects to a better preservation of facial sympathetic function, less occurrence of severe compensatory sweating, and lower incidence of gustatory sweating. We recommend T3 sympathicotomy as a treatment of choice for palmar hyperhidrosis.

Development of Korean Version of Heparin-Coated Shunt / 대한흉부외과학회지

BACKGROUND: This study was designed to develop a Korean version of the heparin-coated vascular bypass shunt by using a physical dispersing technique. The safety and effectiveness of the thrombo-resistant shunt were tested in experimental animals. MATERIAL AND METHOD: A bypass shunt model was constructed on the descending thoracic aorta of 21 adult mongrel dogs(17.5-25 kg). The animals were divided into groups of no-treatment(CONTROL group; n=3), no-treatment with systemic heparinization(HEPARIN group; n=6), Gott heparin shunt (GOTT group; n=6), or Korean heparin shunt(KIST group; n=6). Parameters observed were complete blood cell counts, coagulation profiles, kidney and liver function(BUN/Cr and AST/ ALT), and surface scanning electron microscope(SSEM) findings. Blood was sampled from the aortic blood distal to the shunt and was compared before the bypass and at 2 hours after the bypass. RESULT: There were no differences between the groups before the bypass. At bypass 2 hours, platelet level increased in the HEPARIN and GOTT groups(p<0.05), but there were no differences between the groups. Changes in other blood cell counts were insignificant between the groups. Activated clotting time, activated partial thromboplastin time, and thrombin time were prolonged in the HEPARIN group(p<0.05) and differences between the groups were significant(p<0.005). Prothrombin time increased in the GOTT group(p<0.05) without having any differences between the groups. Changes in fibrinogen level were insignificant between the groups. Antithrombin III levels were increased in the HEPARIN and KIST groups(p<0.05), and the inter-group differences were also significant(p<0.05). Protein C level decreased in the HEPARIN group(p<0.05) without having any differences between the groups. BUN levels increased in all groups, especially in the HEPARIN and KIST groups(p<0.05), but there were no differences between the groups. Changes of Cr, AST, and ALT levels were insignificant between the groups. SSEM findings revealed severe aggregation of platelets and other cellular elements in the CONTROL group, and the HEPARIN group showed more adherence of the cellular elements than the GOTT or KIST group. CONCLUSION: Above results show that the heparin-coated bypass shunts(either GOTT or KIST) can suppress thrombus formation on the surface without inducing bleeding tendencies, while systemic heparinization(HEPARIN) may not be able to block activation of the coagulation system on the surface in contact with foreign materials but increases the bleeding tendencies. We also conclude that the thrombo-resistant effects of the Korean version of heparin shunt(KIST) are similar to those of the commercialized heparin shunt(GOTT).

Facters Affecting Recurrence after Video-assisted Thoracic Surgery for the Treatment of Spontaneous Pneumothotax / 대한흉부외과학회지

BACKGROUND: Recent developments in techniques of video-assisted thoracic surgery(VATS) and endoscopic equipment has expanded the application of video-assisted surgical procedures in the field of thoracic surgery. Especially, it will probably become the treatment of choice of spontaneous pneumothorax(SP). There is, however, a high recurrence rate, high cost, and paucity of long-term results. We report the results of postoperative follow-up and analyze perioperative parameters affected to recurrence, retrospectively. MATERIAL AND METHOD: From march 1992 to march 1997, 276 patients with spontaneous pneumothorax underwent 292 VATS procedures. Conversion to open thoracotomy was necessitated in eight patients, and this patients excluded from the study. RESULT: The sex distribution was 249 males and 31 females. The mean age was 28.1 12.2 years(range, 15 to 69 years). Primary SP was 237cases(83.5%) and secondary SP was 47cases(16.5%). The major underlying lung diseases associated with secondary SP were tuberculosis 27cases(57.4%) and emphysema 8cases (38.3%). Operative indications included Ipsilateral recurrence 123(43.9%), persistent air-leak 53(18.9%), x-ray visible bleb 40(14.3%), tension 30(10.7%), contralateral recurrence 21(7.5%), uncomplicated first episode 8(2.9%), bilateral 3(1.1%), complicated episode 2(0.7%). Blebs were visualized in 247cases(87%) and 244cases(85.9%) performed stapled blebectomy. Early postoperative complications occurred in 33 cases(11.6%): 16 prolonged air-leak more than 5 days(four of them were required a second operation and found missed blebs); 5 bleeding; 5 empyema; 2 atelectasis; 1 wound infection. No deaths occured. The mean operative time was 52.8 23.1 minutes(range, 20 to 165 minutes). The mean d ration of chest tube drainage was 5.0 4.5 days(range, 2 to 37 days). The mean duration ofhospital stay was 8.2 5.5 days (range, 3 to 43days). At a mean follow-up 22.3 18.4 months(range, 1 to 65 months), 12 patients(4.2%) were lost to follow-up. There were 24 recurrences and seven patients underwent second operation and 6 patients(85.7%) were found the missed blebs. 12 perioperative parameters(age, sex, site, underlying disease, extent of collapse, operative indication, size of bleb, number of bleb, location of bleb, bleb management, pleural procedure, prolonged postoperative air-leak) were analyzed statistically to identify significant predictors of recurrence. The significant predictors of recurrence was the underlying disease[17.0%(8/47): 6.8%(16/237), p=0.038], prolonged postoperative air-leakage[37.5%(6/16): 6.7%(18/268), p=0.001], and pleural procedure [11.4%(19/167): 4.3%(5/117), p=0.034]. Blebectomy has less recurrence rate then non-blebectomy [8.2%(20/244) : 10.0%(4/40), p>0. 5]. However, this difference was not statistically significant(p=0.758). CONCLUSION: We conclude that it is important that we shoud careful finding of bleb during VATS due to reducing of recurrnece, and cases of no bleb identified and secondary spontaneous pneumothorax were indicated of pleurodectomy. VATS is a valid alternative to open procedure for the treatment of spontaneous pneumothorax with less pain, shorter hospital stay, more rapid return to work, high patient acceptance, less scar and exellent cosmetics. But, there is high recurrence rate and high cost, and than it is necessary to evaluate of long-term results for recurrence and to observate carefully during VATS.

Calcification-resistant Effect of Surface-modified Biologic Arteries by Sulfonated Polyethyleneoxide / 대한흉부외과학회지

BACKGROUND: Calcific degeneration is the major cause of clinical failure of glutaraldehyde (GA) crosslinked bioprosthetic tissues implanted in the body and necessitates the reoperation or causes death. Surface modification of biologic tissues using sulfonated polyethyleneoixde (PEO-SO3) has been suggested to significantly enhance blood compatibility, biostability and calcification-resistance by means of the synergistic effect of highly mobile and hydrophilic PEO chains and electrical repulsion of negatively charged sulfonate groups. This study was designed to evaluate the anticalcification effect of surface-modification of biologic arteries by direct coupling of PEO-SO3 after GA fixation and changes of calcification according to the implantation period through the quantitative investigation of the deposited calcium and phosphorous contents of the biologic arterial tissues in the canine circulatory implantation model. MATERIAL AND METHOD: Total of 16 fresh canine carotid arteries were harvested from eight adult dogs and divided in to GA group(n =8) and PEO-SO3 group(n=8). Sulfonation of diamino-terminated PEO was performed using propane sultone. Canine carotid arteries were only crosslinked with 0.65% GA solution in GA group and modified by direct coupling 5% PEO-SO3 solution after GA crosslinkage for 2 days and stabilized by NaBH4 solution for 16 hours in PEO-SO3 group. In both groups the resected segment of bilateral carotid arteries were reconstructed. Reconstructed segments of the two groups were analysed the quantities of calcium and phosphorous contents after 3(n=4) and 6(n=4) weeks in vivo. RESULT: After implantation of 3 seeks, PEO-SO3 group showed significantly less depositions.

Thrombolysis for Prosthetic Mitral Valve Thrombosis: 3 cases report / 대한흉부외과학회지

Thrombosis in valve or left atrium after mechanical mitral valve replacement causes prosthetic valve dysfunction or thromboembolism. Early and adequate therapy is very important but clinically not easy. Thrombolysis can avoid reoperation-related risks and act as an optimal therapy for prosthetic valve thrombosis. This report describes three patients who were treated by using low molecular weight heparin (LMWH) and wafarin. Two patients, including one pregnant woman, had prosthetic valve thrombosis and immobility of valve leaflets, and one patient with recent cerebral infarction due to thromboembolism had thrombus in left atrium. Fraxiparine 0.3 cc (7,500 ICU AXa) was administrated subcutaneously twice or triple daily. At discharge, thrombosis in valve and left atrium were completely or near totally lysed and valve leaflets were normally mobile. During the period of thrombolysis and follow up, there were no complications in all patients.

A Case of Endocarditis Related to Pacemaker-Lead Infection / 감염

Endocarditis related to pacemaker-lead infection is a rare complication characterized by infection on the pacemaker electrode tip, tricuspid valve, or the fibrotic endocardial areas that are in contact with the electrode tip. However, it is a serious, potentially life-threatening complication. We experienced a case of pacemaker endocarditis in a 39-year old male patient in whom a permanent pacemaker had been inserted four years before. The diagnosis was made by the demonstration of vegetations on the electrode tip of the pacemaker, that was detected by transthoracic echocardiography and isolation of methicillin-resistant Staphylococcus epidermidis from blood culture. The patient was managed with antibiotics for six weeks and the infected electrode was removed by open heart surgery.