Comprehensive feasibility evaluation of small-diameter 3D templated vascular graft via physical characterizations andin-vivoexperiments.

3D printing (3DP) technology for tissue engineering applications has been extensively studied for materials and processes. However, clinical application to the vascular system was limited owing to mechanical inconsistency and toxicity. Here, we characterized 3D templated artificial vascular grafts (3D grafts), which were fabricated by an integrative method involving 3DP, dip coating, and salt leaching method. The as-fabricated grafts were featured with micrometer-scale porosity enabling tissue-mimetic mechanical softness comparable with native blood vessels. In terms of mechanical properties and water permeability, the fabricated 3D grafts exhibited comparable or superior performances compared to the commercialized grafts. Furthermore, thein-vivostability of the 3D graft was validated through a toxicity test, and the small-diameter 3D graft was transplanted into a rat to confirm the implant's performance. Overall, the experimental results demonstrated the clinical feasibility of the 3D graft with retaining the mechanical biocompatibility and also revealed the possibility of patient-specific customization.

Can concomitant above-knee femoropopliteal bypass with artificial graft affect the outcome of femorofemoral bypass with artificial graft?

OBJECTIVES: Few have studied the effect of concomitant femoropopliteal (FEM-POP) bypass surgery on the outcome of femorofemoral (FEM-FEM) bypass in patients with peripheral arterial disease (PAD). This study was aimed to analyze the risk relationship of concomitant FEM-POP bypass on the patency of FEM-FEM bypass. METHODS: From March 2009 to April 2020, a total of 27 patients who underwent FEM-FEM bypass surgery using polytetrafluoroethylene grafts were retrospectively analyzed according to concomitant FEM-POP bypass surgery. The mean follow-up duration was 38.20 ± 34.56 months. RESULTS: The overall primary patency of the FEM-FEM bypass grafts in all 27 patients was 83.7, 78.5, and 72.0 at one, two, and 3 years, respectively. The overall limb salvage rate was 100, 94.1, and 86.9 at one, two, 3 years, respectively. Among them, ten patients underwent FEM-FEM bypass only (group 1). The other 17 patients needed a concomitant FEM-POP bypass and these patients were classified into three groups (group 2, ipsilateral FEM-POP, n = 5; group 3, crossover FEM-POP, n = 6; and group 4, bilateral FEM-POP, n = 6) The comparison of the primary patency of group 1 with the concomitant FEM-POP groups (sum of groups 2, 3, and 4, that is, group 5, n = 17) revealed a statistically significant improved patency for FEM-FEM bypasses not requiring concomitant infra-inguinal bypass (p = .036). Among the concomitant FEM-POP groups, group 2 had the lowest primary patency of the FEM-FEM bypass significantly (p = 0.07). The limb salvage rate of group 4 was significantly low. CONCLUSIONS: A concomitant FEM-POP bypass influenced the outcome of FEM-FEM bypass surgery. In conclusion, compromised infra-inguinal runoff at either extremity requiring concomitant FEM-POP bypass significantly worsens long-term FEM-FEM bypass patency. In addition, a concomitant bilateral FEM-POP bypass is a risk factor affecting the limb salvage rate in FEM-FEM bypass.

Evaluation of 3D Templated Synthetic Vascular Graft Compared with Standard Graft in a Rat Model: Potential Use as an Artificial Vascular Graft in Cardiovascular Disease.

Although the number of vascular surgeries using vascular grafts is increasing, they are limited by vascular graft-related complications and size discrepancy. Current efforts to develop the ideal synthetic vascular graft for clinical application using tissue engineering or 3D printing are far from satisfactory. Therefore, we aimed to re-design the vascular graft with modified materials and 3D printing techniques and also demonstrated the improved applications of our new vascular graft clinically. We designed the 3D printed polyvinyl alcohol (PVA) templates according to the vessel size and shape, and these were dip-coated with salt-suspended thermoplastic polyurethane (TPU). Next, the core template was removed to obtain a customized porous TPU graft. The mechanical testing and cytotoxicity studies of the new synthetic 3D templated vascular grafts (3DT) were more appropriate compared with commercially available polytetrafluoroethylene (PTFE) grafts (ePTFE; standard graft, SG) for clinical use. Finally, we performed implantation of the 3DTs and SGs into the rat abdominal aorta as a patch technique. Four groups of the animal model (SG_7 days, SG_30 days, 3DT_7 days, and 3DT_30 days) were enrolled in this study. The abdominal aorta was surgically opened and sutured with SG or 3DT with 8/0 Prolene. The degree of endothelial cell activation, neovascularization, thrombus formation, calcification, inflammatory infiltrates, and fibrosis were analyzed histopathologically. There was significantly decreased thrombogenesis in the group treated with the 3DT for 30 days compared with the group treated with the SG for 7 and 30 days, and the 3DT for 7 days. In addition, the group treated with the 3DT for 30 days may also have shown increased postoperative endothelialization in the early stages. In conclusion, this study suggests the possibility of using the 3DT as an SG substitute in vascular surgery.

Anti-thrombotic and anti-inflammatory activity of sulodexide compared to aspirin in the rat model.

BACKGROUND: Although the number of vascular surgeries performed is increasing, the incidence of complications associated with this surgery has not improved and re-operations are frequently required. Thrombosis in a vessel is the most hazardous postoperative complication. OBJECTIVE: The aim of this study was to evaluate the anti-thrombotic and anti-inflammatory effects of sulodexide compared to aspirin in a rat model. METHODS: We divided the animals into three groups (sham (saline), aspirin, and sulodexide). The abdominal aorta was surgically opened and closed, primarily with 8/0 Prolene sutures. Postoperatively, saline, aspirin, or sulodexide was administered by oral gavage for 14 days to the rats. The degree of neovascularization, thrombus, calcification, inflammatory infiltrates, and fibrosis were analyzed histopathologically by hematoxylin and eosin staining. RESULTS: There was no significant difference in the incidence of postoperative thrombogenesis, but less calcification and inflammatory infiltrates were observed in the sulodexide group compared to the aspirin group. Histopathologic score revealed less infiltration of inflammatory cells and mild calcification for the sulodexide group (0.17±0.41 and 1.33±0.52, respectively) compared to the aspirin group (0.67±0.52 and 1.67±0.52, respectively) at days 14. CONCLUSIONS: This study offers the possibility that sulodexide could be used as an aspirin substitute for the postoperative management of vascular patients, with low gastrointestinal discomfort. In addition, it may also offer reduced postoperative calcification and inflammation.

Thoracomyoplasty for Chronic Empyema and Osteoradionecrosis of the Chest Wall

Herein, we report a case in which thoracomyoplasty was performed to manage chronic postlobectomy empyema (PLE). A 54-year-old male patient with a surgical history of right upper lobectomy and thymectomy 35 years previously who had undergone adjuvant radiotherapy presented with purulent discharge on the anterior chest wall. The patient was diagnosed with chronic PLE with ascending infection and concurrent osteonecrosis of the parasternum. Proper drainage was performed for local infection control and the dead spaces were successfully closed with muscle flaps. There have been no complications to date.

Comparison of clinical outcomes of pharmaco-mechanical thrombectomy in iliac vein thrombosis with and without May-Thurner syndrome.

BACKGROUND: May-Thurner syndrome (MTS) has a different etiology from that of general deep vein thrombosis (DVT). However, few clinical comparisons of MTS-induced and non-MTS-induced DVT have been reported. The aim of this study was to analyze the clinical results of pharmaco-mechanical thrombectomy (PMT) in DVT with and without MTS. METHODS: Forty-seven iliac vein thrombosis patients treated with PMT between January 2008 and December 2013 were enrolled. 25 patients had DVT with MTS and 22 patients had iliac vein DVT without MTS. We retrospectively reviewed medical records and analyzed mid-term patencies and post-thrombotic syndrome (PTS) occurrence by Villalta Score. RESULTS: The median follow-up period was 48.4 (36~92) months. A venous stent was inserted in the iliac vein in all MTS patients. One-/two-/three-year primary patencies in the non-MTS group were 77.3% (N.=17) for all three years in the non-MTS group and were 96.0% (N.=24), 83.1% (N.=22), and 83.1% (N.=22) in the MTS group for years 1/2/3, respectively. One-/two-/three-year secondary patencies were 90.9% (N.=20) for all three years in the non-MTS group and were 96.0% (N.=24), 91.4% (N.=23), and 91.4% (N.=23) in the MTS group, respectively. One-, two-, and three-year Villalta Scores were 4.3, 3.9, and 3.4, respectively, in the non-MTS group, and 3.8, 3.7, and 4.0, respectively, in the MTS group. Primary and secondary patency and Villalta Score were not significantly different between the MTS and non-MTS groups. CONCLUSIONS: Although MTS and DVT have different etiologies, clinical results for both diseases using PMT were not significantly different. Therefore, PMT can be offered as an acceptable initial therapy in DVT patients with and without MTS.

Video-assisted thoracoscopic surgery for intrathoracic first rib resection in thoracic outlet syndrome.

BACKGROUND: First rib resection is a surgical treatment for decompressing the neurovascular structures in thoracic outlet syndrome (TOS). Historically, extrathoracic approaches have used a posterior, supraclavicular, or transaxillary incision to remove the first rib. In this report, we demonstrate video-assisted thoracoscopic surgery for intrathoracic first rib resection (VATS-IFRR). METHODS: Between 2009 and 2014, eight patients underwent VATS-IFRR for TOS. Surgery was performed through two 5-mm ports and one 10-mm port. Endoscopic graspers, a hook-type electrocautery probe, a long peapod intervertebral disc rongeur, and Kerrison punches were used. The types of disease, operative times, chest tube indwelling days, lengths of hospital stay after operation, perioperative complications, postoperative pain scale ratings, and postoperative symptom recurrence rates at provocation tests were reviewed. The surgical outcomes were compared to published outcomes of extrathoracic approaches and other VATS approaches. RESULTS: The eight patients (3 right ribs, 5 left ribs) exhibited neurogenic (1 patient), combined type (2 patients), arterial (4 patients), and venous type (1 patient) TOS. The mean operative time was 190 (range 155-310) minutes. No mortalities or major complications occurred. The mean chest tube indwelling duration was 6 (range 3-10) days, and the mean postoperative hospital stay was 9 (range 4-21) days. The mean immediate postoperative pain numeric rating scale (NRS) score was 2.7/10 (range 2-4). No recurrence was observed during follow-up (median 25.5 months, range 10-64 months) in any patient. CONCLUSIONS: VATS-IFRR was safe and had several advantages. Thus, VATS-IFRR is a minimally invasive surgical option suitable for treating selective cases of TOS.

Effects of a Proteasome Inhibitor on Cardiomyocytes in a Pressure-Overload Hypertrophy Rat Model: An Animal Study.

BACKGROUND: The ubiquitin-proteasome system (UPS) is an important pathway of proteolysis in pathologic hypertrophic cardiomyocytes. We hypothesize that MG132, a proteasome inhibitor, might prevent hypertrophic cardiomyopathy (CMP) by blocking the UPS. Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and androgen receptor (AR) have been reported to be mediators of CMP and heart failure. This study drew upon pathophysiologic studies and the analysis of NF-κB and AR to assess the cardioprotective effects of MG132 in a left ventricular hypertrophy (LVH) rat model. METHODS: We constructed a transverse aortic constriction (TAC)-induced LVH rat model with 3 groups: sham (TAC-sham, n=10), control (TAC-cont, n=10), and MG132 administration (TAC-MG132, n=10). MG-132 (0.1 mg/kg) was injected for 4 weeks in the TAC-MG132 group. Pathophysiologic evaluations were performed and the expression of AR and NF-κB was measured in the left ventricle. RESULTS: Fibrosis was prevalent in the pathologic examination of the TAC-cont model, and it was reduced in the TAC-MG132 group, although not significantly. Less expression of AR, but not NF-κB, was found in the TAC-MG132 group than in the TAC-cont group (p<0.05). CONCLUSION: MG-132 was found to suppress AR in the TAC-CMP model by blocking the UPS, which reduced fibrosis. However, NF-κB expression levels were not related to UPS function.

The Role of Pharmacomechanical Endovascular Intervention for Iliofemoral Vein Thrombosis Compared to Conventional Anticoagulation Therapy.

Although anticoagulation therapy is the primary treatment for deep vein thrombosis (DVT), it has not been associated with the rapid recanalization of the venous occlusion. Moreover, it is associated with long-term disability due to post-thrombotic syndrome (PTS). In contrast, pharmacomechanical endovascular intervention (PMI) results in more rapid clinical improvement in DVT patients, but there are few reports on its long-term outcomes. This retrospective study evaluated the clinical effectiveness of PMI compared to conventional anticoagulation therapy (ACA) for acute and subacute iliofemoral DVT. We reviewed the medical records of 102 patients with iliofemoral DVT. A total of 46 patients for ACA and 56 patients for PMI were enrolled. We analyzed the clinical differences between the PMI and ACA groups by comparing the clinical signs, residual DVT free-rate, and PTS-free rate. There were no statistically significant differences in the demographic characteristics and risk factors except age between the groups (age: ACA, 52.0 ± 18.0 years; PMI, 59.0 ± 17.0 years; P = 0.035). The 1-, 3-, and 5-year residual DVT-free rate (ACA = 84.7%, 71.6%, and 46.0%; PMI = 82.1%, 76.8%, and 76.8%, respectively; P = 0.235) was not significantly different. However, the 1-, 3-, and 5-year PTS-free rate was significantly different (ACA = 93.5%, 74.0%, and 55.7%; PMI = 92.9%, 90.0%, and 90.0%, respectively; P = 0.019). There was no significant difference in the rate of other complications. PMI showed a lower incidence of PTS during the follow-up period. Therefore, PMI should be considered as an effective therapeutic modality for patients with iliofemoral DVT.

Deep-seated intramuscular lipoma penetrates the intercostal muscle.

Deep-seated intramuscular lipomas are rare, and most exhibit an infiltrating behavior. This study reports serial radiographs of a lipoma in chest wall muscles which penetrated the intercostal muscle for a 6-year period. Although this lipoma did not involve the parietal pleura, it compressed lung. To the authors' knowledge, the present study is the first report to show the growth of a deep-seated chest wall lipoma into the thoracic cavity through serial radiographs. We consider the surgical treatment is needed before deep-seated intramuscular chest wall lipoma compress intrathoracic structures.

Gap junction remodelling by chronic pressure overload is related to the increased susceptibility to atrial fibrillation in rat heart.

AIMS: Left atrial (LA) fibrosis caused by various pathological stimuli is a common finding. However, the difference of atrial remodelling via haemodynamic change in diverse cardiomyopathy has not been elucidated. METHODS AND RESULTS: Male Sprague-Dawley rats (6-8 weeks, n = 180) were randomly assigned to three groups and corresponding sham control groups: (i) ischaemic cardiomyopathy, (ii) left ventricular hypertrophy (LVH), and (iii) dilated cardiomyopathy. At 12 weeks after operation, atrial fibrillation (AF) inducibility and duration were assessed by in vivo burst transoesophageal pacing. Using the Langendorff apparatus, left ventricular (LV) function and pressure were measured. The expression of connexin-43 (Cx43) and alpha-smooth muscle actin (α-SMA) in atrial tissues was assessed by quantitative real-time polymerase chain reaction and immunohistochemical staining. Fibrosis was analysed by Masson's trichrome staining. Compared with controls, the LA weight/heart weight ratio was increased in the LVH group alone, and was significantly correlated with AF duration (P < 0.001, R = 0.388). Atrial fibrillation inducibility and duration were higher and longer only in the LVH group (P = 0.002, 0.079, respectively), and isolated LV diastolic dysfunction and elevated LV pressure were observed. Although α-SMA expression and fibrosis were increased in all three cardiomyopathy models, down-regulation of Cx43 expression in the LA was observed in the LVH group alone. CONCLUSION: Chronic pressure overload in the absence of LV systolic dysfunction resulted in LA hypertrophy and increased susceptibility to AF, which might be related to conduction abnormality via decreased expression and lateral distribution of Cx43 as well as interstitial fibrosis.

The protective effect of heat shock protein 70 (Hsp70) in atrial fibrillation in various cardiomyopathy conditions.

Heat shock proteins (Hsp) protect myocardial cells from acute stress such as atrial fibrillation (AF) and also from the chronic stress. It is not understood that Hsp70 can prevent AF under cardiomyopathy (CM) conditions. Therefore, we hypothesized that Hsp70 might beneficially influence on the occurrence of AF in CM conditions. We purposed to investigate the correlation between Hsp70 and the AF inducibility in various CM conditions that are unclear. We constructed four different animal models using Sprague-Dawley rats: an ischemic CM group (n = 12), a non-ischemic dilated CM group (n = 12), a pressure-overload hypertrophic CM group (n = 12), and a sham group (CON, n = 12). After 4-6 weeks of intervention animals, AF was induced acutely prior to hemodynamic studies. Hemodynamic data using the Langendorff technique and histologic evaluation were conducted sequentially in all animal groups. Afterwards, levels of Hsp70 were measured from atrial tissues by real-time polymerase chain reaction study. The hemodynamic data and histologic studies proved that each animal model was suitable to this study protocol. All CM groups showed that Hsp70 was elevated significantly compared to the control groups (P < 0.005). Among these CM groups, the TAC group revealed lower Hsp70 levels and higher induction rates of atrial fibrillation than the other groups (P < 0.005). The level of Hsp70 was elevated in all the CM models and it was negatively correlated with AF induction rate in sham group. However, we could not find correlation between Hsp70 and AF among the CM models.

Thrombosis in Behçet's disease: a Behçet's disease patient with complete thrombotic obstruction of IVC and both iliac veins and decreased protein S activity.

Behçet's disease represents a multisystemic inflammatory disease characterized by recurrent oral ulcers, genital ulcers, and uveitis. Although vascular attack and thrombosis are not major complications in Behçet's disease, they can still pose risks that must not be overlooked. In this paper, we reported that a 25-year-old female Behçet's disease patient with complete thrombotic obstruction of the inferior vena cava that was successfully treated by aspiration thrombectomy and balloon angioplasty. The procedure produced marked symptomatic improvement. Currently, data about the treatment and the prophylaxis of thrombotic events in Behçet's disease are lacking. In this case report, we hope to discuss the future direction of such studies, how we understand the mechanism of Behçet's disease hypercoagulability, and which treatments can improve thrombotic tendencies in Behçet's disease.

Minimally invasive repair of pectus excavatum: a novel morphology-tailored, patient-specific approach.

OBJECTIVE: Minimally invasive repair of pectus excavatum, introduced by Nuss in 1998, has undergone a serious learning curve because of a lack of understanding on morphologies and repair techniques. To summarize the current status of minimally invasive repair of pectus excavatum, we reviewed and appraised our 10-year experience with a novel approach, a morphology-tailored technique, including diverse bar shaping, bar fixation, and techniques for adults. METHODS: We analyzed the data of 1170 consecutive patients with pectus excavatum who underwent minimally invasive repair between August 1999 and September 2008. All pectus repairs were performed by the primary author (H.J.P.) with our modified technique. RESULTS: The mean age was 10.3 years (range, 16 months to 51 years). There were 331 adult patients (>15 years) (28.3%). A total of 576 patients (49.2%) had bar removal after a mean of 2.5 years (range, 10 days to 7 years). The asymmetry index change (1.10-1.02, P < .001) demonstrated post-repair symmetry. Complication rates decreased through the 3 time periods (1999-2002 [n = 335]; 2003-2005 [n = 441]; 2006-2008 [n = 394]) as follows: pneumothorax rate (7.5% vs 4.3% vs 0.8%; P < .001) and bar displacement rate (3.8% vs 2.3% vs 0.5%; P = .002). Reoperation rate also decreased (4.8% vs 2.5% vs 0.8%; P = .002). Satisfaction outcomes were excellent in 92.7%, good in 5.9%, and fair in 1.4% of patients. After bar removal, 3 patients (0.6%) had minor recurrences. CONCLUSION: Minimally invasive repair of pectus excavatum based on a novel morphology-tailored, patient-specific approach is effective for quality repair of the full spectrum of pectus excavatum, including asymmetry and adult patients. Continuous technical refinements have significantly decreased the complication rates and postoperative morbidity.

Myocardial protective effect of tezosentan, an endothelin receptor antagonist, for ischemia-reperfusion injury in experimental heart failure models.

The myocardial protective effects of endothelin antagonist in ischemic cardiomyopathy (ICMP), doxorubicin-induced cardiomyopathy (DOX) and pressure-overload hypertrophy by transverse aortic constriction (TAC) models have been predicted to be different. The objective of this experiment, therefore, is to evaluate the myocardial protective effect of tezosentan, an endothelin receptor antagonist, in various experimental heart failure models. Sprague-Dawley rats (6-8 weeks old, 200-300 g) were randomized to three experimental groups (n=30 each): ICMP; DOX; and TAC group. Each of these groups was randomly assigned further to the following subgroups (n=10 each): sham-operated ischemia-reperfusion subgroup (SHAM); tezosentan treated ischemia-reperfusion subgroup (Tezo); and tezosentan non-treated ischemia-reperfusion subgroup (N-Tezo). Total circulatory arrest was induced for 1 hr, followed by 2 hr of reperfusion. The left ventricular developed pressure, peak positive and negative first derivatives, and coronary blood flow were significantly different (P<0.05) among the SHAM, Tezo, and N-Tezo subgroups of the ICMP group at 30 min of reperfusion, but there were no statistically significant differences among the subgroups of the DOX and TAC groups. In conclusion, tezosentan, an endothelin receptor antagonist, showed myocardial protection effects only on the ischemic cardiomyopathy rat model, but not in the non-ischemic heart failure rat models.

Unexpected stent thrombus after minimally invasive direct coronary artery bypass in hybrid re-vascularisation.

The progress in anti-platelet therapy and percutaneous coronary intervention led to reconfigure indications of hybrid re-vascularisation. However, there are still some controversies over indication, timing and patient management during the procedure. The case discussed here is a patient who was diagnosed with myocardial infarction and treated with hybrid re-vascularisation. The patient underwent stent insertion followed by bypass surgery. After the hybrid procedure, the patient was stable but eventually died on the 12th day after the surgery owing to unexpected stent thrombosis. We discuss the current controversy over hybrid re-vascularisation, variables that can affect the outcome and the requirement for establishing accurate logistics based on our case.

Needlescopic lung biopsy for interstitial lung disease and indeterminate pulmonary nodules: a report on 65 cases.

BACKGROUND: We evaluated the feasibility and accuracy of a needlescopic procedure for lung biopsies in patients with interstitial lung disease or indeterminate pulmonary nodules. METHODS: Sixty-five patients (36 women; mean age, 51.3 +/- 15.6; range, 13 to 76 years) underwent a needlescopic procedure to obtain lung biopsy specimens. Forty had indeterminate pulmonary nodules, and 25 had interstitial lung disease. A 2-mm needlescope and a 2-mm MiniSite Endo Grasp (Covidien, Norwalk, CT) were inserted at the sixth intercostal space along the middle and the posterior axillary line, respectively. Biopsy specimens were obtained using endostaplers. RESULTS: The average number of biopsy specimens was 1.7 +/- 0.6 (range, 1 to 4). For 9 patients, a frozen specimen was sent twice to pathology. Complete resection was continued after intraoperative pathology confirmation in 13 patients (lobectomy, 7; segmentectomy, 3; mass removal, 1; metastasectomy, 2). The volume of lung tissue was 8.7 +/- 11.8 cm3 (range, 0.15 to 55.44 cm3). The operation time was 58.7 +/- 37.5 minutes (range, 15 to 160 minutes). The final pathologic results were confirmed in all patients. No thoracoscopic procedure was converted to an open thoracotomy. Three patients (4.3%) had prolonged air leakage (> 5 days), and the chest tube remained in the pleural space for 2.3 +/- 2.4 days (range, 1 to 8 days). CONCLUSIONS: Needlescopic operation for lung biopsies in patients with interstitial lung disease and indeterminate pulmonary nodules is a minimally invasive procedure that is safe and effective for obtaining a diagnosis in selected patients.

Effects of additional pleurodesis with dextrose and talc-dextrose solution after video assisted thoracoscopic procedures for primary spontaneous pneumothorax.

Recurrence after thoracoscopic surgery for primary spontaneous pneumothorax is a lingering problem, and many intraoperative methods to induce pleural symphysis have been introduced. We analyzed the effects of chemical pleurodesis during thoracoscopic procedures. Between August 2003 and July 2005, 141 patients among indicated surgical treatment for primary spontaneous pneumothorax in two hospitals of our institution allowed this prospective study. The patients were randomly assigned to 3 groups: thoracoscopic procedure only (group A, n=50), thoracoscopic procedure and pleurodesis with dextrose solution (group B, n=49), and thoracoscopic procedure and pleurodesis with talc-dextrose mixed solution (group C, n=42). There was no significant difference in demographic data among the three groups. The two groups that underwent intraoperative pleurodesis had significantly longer postoperative hospital stays (A/B/C: 2.50+/-1.85/4.49+/-2.10/6.00+/-2.58 days; p=0.001) and a higher incidence of postoperative fever (A/B/C: 10.0/22.45/52.38%; chi(2)= 21.598, p=0.00). No significant differences were found for recurrence rates or the number of postoperative days until chest tube removal. Therefore, the results of our study indicate that intraoperative chemical pleurodesis gives no additional advantage to surgery alone in deterring recurrence for patients with primary spontaneous pneumothorax. Thus, the use of such scarifying agents in the operating room must be reconsidered.