Search

Background Concerns of gastrointestinal (GI) bleeding after cardiac surgery are increasing with increased use of antiplatelets and anticoagulants. We investigated the roles of preoperative screening for fecal occult blood by fecal immunochemical test (FIT) widely used to detect GI bleeding and cancer. Methods A retrospective review was done in 1,663 consecutive patients undergoing FIT before cardiac surgery between years 2012 and 2020. One or two rounds of FIT were performed 2 to 3 weeks before surgery, when antiplatelets and anticoagulants were not suspended yet. Results Positive FIT (> 30 μg of hemoglobin/g of feces) was observed in 227 patients (13.7%). Preoperative risk factors for positive FIT included age > 70 years, anticoagulants, and chronic kidney disease. Of those with positive FIT, 180 patients (79%) received preoperative endoscopy, including gastroscopy (n = 139), colonoscopy (n = 9), and both (n = 32), with no findings of bleeding. The most common finding of gastroscopy was atrophic gastritis (36%) while early gastric cancer was detected in 2 patients. The most common finding of colonoscopy was colon polyps (42%) while colorectal cancer was detected in 5 patients. Of 180 FIT-positive patients receiving endoscopy, 8 (4.4%) underwent preoperative GI treatment, while postoperative GI events were documented in 28 (15.6%). Of 1,436 with negative FIT, 21 (1.5%) presented GI complications after surgery. Conclusion Preoperative FIT, which is influenced by anticoagulant use, has little impacts on identification of GI bleeding sites. However, it may be useful to detect GI malignant lesions, potentially impacting operative risks, surgical strategies, and postoperative management.

Thermoreactive nitinol Flexigrip has been developed to ensure better fixation than conventional wire closure. To verify the advantage of Flexigrip over the conventional wiring, we compared early sternal bone healing on computed tomography (CT).A prospective cohort study enrolled the first consecutive 80 patients with wiring and the second consecutive 44 patients undergoing Flexigrip sternal closure. The primary endpoint was sternal healing evaluated quantitatively using a 6-point scale and measured gaps/offsets of the sternal halves at 6 levels on CT scans on the 14th postoperative day. Secondary endpoints included pain scores and sternal complications 1 month after surgery.Compared with the patients of wiring, those who received Flexigrips showed higher 6-point scores at most sternum levels, less frequent gaps (52% vs 70%, p = 0.04), lower offsets (3.3 ± 0.9 mm vs 4.3 ± 0.7 mm, p0.001) at the manubrium, and less frequent gaps (25% vs 43%, p = 0.04) and offsets (2.3% vs 24%, p = 0.002) at the middle of sternum. The pain scores and sternal complication rates were similar between both groups.CT evaluation 2 weeks after surgery revealed that Flexigrip sternal closure showed less gaps and offsets of the sternal halves, suggesting faster sternal bone union when compared to the wiring.

We report a case of mechanical prosthetic mitral valve thrombosis in a 52-year-old woman with previous diagnosis of dilated cardiomyopathy, who was supported with advanced mechanical circulatory support after urgent mechanical mitral valve replacement (MVR) and tricuspid annuloplasty. Difficult weaning from cardiopulmonary bypass needed support with veno-arterial extracorporeal membranous oxygenation and Impella (Abiomed Inc, Danvers, MA, USA), so-called ECPELLA. Temporary discontinuation of heparin and massive blood transfusion were necessary due to four times of reoperation for bleeding during ECPELLA support. Poor recovery of cardiac function needed escalation from ECPELLA to extracorporeal biventricular assist device (ex-BiVAD) using two centrifugal pumps on Day 12. After gradual decrease in the left ventricular assist device flow, transesophageal echocardiography and fluoroscopic images revealed the stuck leaflets of the mitral prosthesis. Therefore, the patient underwent re-MVR with a bioprosthesis on Day 18, followed by continued assistance with ex-BiVAD. The patient was finally weaned from ex-BiVAD on Day 28 and was transferred to the referral hospital for rehabilitation. She was alive in good general condition at 2-year follow-up. It is important to balance the effects of anticoagulation on advanced mechanical circulatory support with ECPELLA, against the side effects of bleeding, especially in post-cardiotomy patients with bleeding tendency.

We report wound management using a vacuum-assisted closure (VAC) system for the cannula sites of extracorporeal biventricular assist devices (BiVADs) for 295 days in a 23-year old Chinese female patient with fulminant giant cell myocarditis, who finally underwent heart transplantation. When the cannula sites appeared necrotic 3 months after BiVADs placement, she received negative pressure wound therapy prophylactically for four cannula sites, using a VAC system for 3 months, followed by no infections. Such prophylactic VAC therapy, using the skin barrier paste usually used for the ostomy pouching system to create a flatter surface and airtightness, may be useful to avoid cannula site infections, which is still a fatal complication causing sepsis, especially in patients with extracorporeal BiVADs.

Background Circulating microRNAs (miRNAs, miR) have been considered as biomarkers reflecting the underlying pathophysiology in atrial fibrillation (AF). Nevertheless, miRNA expression in the peripheral blood samples might not reflect a cardiac phenomenon since most miRNAs are expressed in numerous organs. This study aimed to identify the cardiac-specific circulating miRNAs as biomarkers for AF. Methods Plasma samples were obtained from a luminal coronary sinus catheter (CS, cardiac-specific samples) and femoral venous sheath (FV, peripheral samples) in patients with AF and paroxysmal supraventricular tachycardia (control, CTL) undergoing catheter ablation. The circulating miRNA profiles were analyzed by small RNA sequencing. Differently expressed miRNAs between AF and CTL were identified in each sample of the CS and FV; miRNAs exhibiting similar expression patterns in the CS and FV samples were selected as candidates for cardiac-specific biomarkers. The selected miRNAs were related to the outcome of catheter ablation of AF. Results Small RNA sequencing detected 849 miRNAs. Among the top 30 most differently expressed miRNAs between AF and CTL, circulating hsa-miR-20b-5p, hsa-miR-330-3p, and hsa-miR-204-5p had a similar pattern in the CS and FV samples. Another set of peripheral blood samples was obtained from AF patients undergoing catheter ablation (n = 141). The expression of the miR-20b-5p and miR-330-3p, but not the miR-204-5p, negatively correlated with the echocardiographic left-atrial dimension and was decreased in patients with AF recurrence as compared to those without AF recurrence during a 1-year follow-up. Conclusion Circulating miR-20b-5p and miR-330-3p can be cardiac-specific biomarkers for atrial remodeling progression and arrhythmia recurrence after catheter ablation in AF patients.

Background Thoracic aortitis caused by Clostridium septicum is a rare infection with a strong association with malignancy and high mortality rate when left untreated. We report a case of surgical treatment for Stanford type A acute aortic dissection in a patient with C. septicum sepsis and thoracic aortitis. Case presentation A 63-year-old hypertensive man with rheumatoid arthritis presented with general malaise and diagnosed with C. septicum-infected aortitis with sepsis. On the 5th day of hospitalization, Stanford type A acute aortic dissection developed with severe aortic regurgitation. The patient underwent emergent surgical treatment successfully with excision of the infected ascending aorta and aortic root followed by replacement using a composite graft, followed by diagnosis of sigmoid colon cancer 7 months after aortic surgery. He was scheduled to undergo elective colon surgery. Conclusions C. septicum aortitis can progress quickly, causing aneurysm or dissection. Therefore, in a patient with C. septicum aortitis, prompt surgical in situ graft replacement should be performed to debride the infected vascular lesions. Further investigations for gastrointestinal and hematological malignancies as a source of C. septicum should be also conducted.

OBJECTIVES Patients with cardiovascular disease are vulnerable to severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) infection. Although SARS-CoV2 vaccination may be effective, its impact on surgical patients is not well studied. We investigated the effects of cardiovascular surgery, especially under cardiopulmonary bypass (CPB), on the antibody titres after SARS-CoV2 vaccination. METHODS A prospective observational study was designed for patients undergoing surgery between July and November 2021. The immunoglobulin G against the receptor-binding domain was measured and antibody preserved rate (APR) was calculated from perioperative titres comparison. RESULTS Enrolled 63 study patients were divided into 39 undergoing surgery with CPB (Group CPB) and 24 without CPB (Group None). Preoperative vaccines were BNT162b2 (Pfizer/BioNTech) (n = 58, 92%) and mRNA-1273 (Moderna) (n = 5, 8%). While immunoglobulin G against the receptor-binding domain titres did not significantly decrease after surgery in Group None, they decreased significantly in Group CPB from 21.80 [11.15, 37.85] to 11.95 [6.80, 18.18] U/ml (P CONCLUSIONS The SARS-CoV2 antibody titres significantly decreased with lower APRs immediately after surgery under CPB. Based on our informative results, careful considerations of vaccination schedule might be required for surgery under CPB.

A 70-year-old patient who survived about 40 years after left pneumonectomy for tuberculosis visited emergency hospital, because of dyspnea. She received suitable medical therapy for atirial fibrillation and severe mitral regurgitation and hesitated heart surgery because of anxiety for surgical risk. The computed-tomography showed mediastinal shift to left and right lung compensatory expansion. Respiratory function test after treatment of heart failure showed only mild restrictive disorder. And the blood-gas examination in room air was 101 mmHg of Pao2 and 37 mmHg of Paco2. The mitral valve replacement was performed via median sternotomy and using normal cardiopulmonary bypass. And she fully recoverd without any respiratory complications. Mediastinal shift did not obstract the surgical view and establishment of cardiopulmonary bypass in this case. It seemed that the key of surgical successs is the preserved function of healthy residual lung.

Kommerell diverticulum (KD) is an aneurysm of the orifice of an aberrant subclavian artery (SCA) from the descending aorta or aortic arch. We have performed two-staged surgical strategy for the treatment of KD with right aortic arch. The first step was the bypass grafting between the left common carotid artery and the aberrant left SCA with occlusion of the distal side of KD with the plug. The second step was the descending aorta replacement through the right thoracotomy. Four patients underwent these operations. No hospital deaths or major complications were observed. All four patients were discharged and have been alive for 1-6 years without any health problems. Two of four patients had symptoms of dysphagia preoperatively, and it resolved postoperatively in both patients. No hoarseness occurred after surgery, and 1-6 years of CT observation showed no recanalization of the vascular plug.

We report wound management using a vacuum-assisted closure (VAC) system for the cannula sites of long-term extracorporeal biventricular assist devices (BiVADs). A 23-year old Chinese female patient with a diagnosis of giant cell myocarditis needed extracorporeal BiVADs for more than 9 months. When the cannula sites appeared necrotic 3 months after BiVADs placement, she underwent negative pressure wound therapy prophylactically for four cannula sites, using a VAC system for 3 months, followed by no infections. Such prophylactic VAC therapy may be useful to avoid cannula site infections, which is still a fatal adverse event causing sepsis, especially in patients with extracorporeal BiVADs.

The frozen elephant trunk (FET) technique allows single-stage extended surgical repair of Stanford type A aortic dissection and has shown promotion of aortic remodeling by maintaining the true lumen flow and facilitating its expansion and by promoting false lumen thrombosis. However, few studies have compared the effectiveness of FET technique, in terms of the downstream aortic remodeling. Between 2005 and 2017, 50 patients underwent total arch replacement for Stanford type A aortic dissection, including that with (n = 22) and without FET technique (n = 28). We compared distal aortic remodeling in patients who underwent total arch replacement with (using a J-Graft open stent graft) or without the technique. The false lumen complete thrombosis rate and the ratio of true lumen area at three levels of the descending aorta were evaluated post operation. In FET group, the diameter and length of the stent graft were 29.0 ± 3.9 mm and 70.9 ± 17.4 mm, respectively. The in-hospital death with and without the FET technique was 0 and 3, respectively, with no late death in both groups. Eight patients (28.6%) only in the non-FET group required additional surgical treatment for downstream aorta. In the FET group, the ratio of true lumen area at the level of bronchial carina and false lumen complete thrombosis rate at the levels of bronchial carina and aortic valve were significantly higher than non-FET group. A more favorable remodeling in the descending aorta was observed in patients who underwent FET associated with a total arch replacement compared to those who underwent total arch replacement alone.

Background Transit-time flow measurement (TTFM) is frequently used for intraoperative graft flow analysis during coronary artery bypass grafting (CABG). Although the TTFM results may be influenced by fractional flow reserve (FFR) of the target coronary artery as a determinant of coronary lesion-specific ischemia, the data have been limited. Methods We retrospectively investigated the relationships between the intraoperative TTFM variables and preoperative FFR values of the target coronary arteries in 40 in situ left internal thoracic artery (LITA) grafts to the left anterior descending artery (LAD), which were revealed to be patent on postoperative computed tomographic angiography. Results The Spearman correlation coefficients of the TTFM variables with FFR were maximum flow, −0.12 (P = .301); minimum flow (Qmin), −0.43 (P = .004); mean flow (Qm), −0.30 (P = .036); pulsatility index, 0.37 (P = .012); diastolic filling, −0.36 (P = .012); percentage insufficiency, 0.45 (P = .002); and fast Fourier transform (FFT) ratio, −0.07 (P = .329). While Min and Qm showed significant negative correlation, the pulsatility index and percentage insufficiency showed significant positive correlation with FFR. Conclusions Most TTFM variables, including Qm, of the LITA graft to the LAD during CABG are strongly affected by preoperative FFR values. Because the FFT ratio is not influenced by FFR, FFT analysis of the TTFM may be recommend in the case of the in situ LITA graft to the LAD with moderate stenosis with a higher FFR exceeding 0.75.

Introduction: Ventricular assist device is used in the patients with severe heart failure due to cardiotoxicity of anthracyclines, which are widely used chemotherapeutic agents for a wide range of malignant tumors. However, recovery of cardiac function is rare. Methods: We present the clinical course of a 43-year-old woman in remission from diffuse large B-cell lymphoma after the chemotherapy including anthracyclines, who presented in cardiogenic shock 8 months after the end of chemotherapy. Results: The patient was initially treated with intra-aortic balloon pumping, followed by conversion to left ventricular assist device with an Abiomed AB5000 (Abiomed, Inc, Danvers, MA) and right ventricular assist device with a centrifugal pump and a membrane oxygenator, in addition to tricuspid annuloplasty, due to rapid deterioration to cardiogenic shock. With intensive medical treatments during biventricular support, her cardiac and respiratory functions gradually improved, although moderate mitral regurgitation persisted despite of left ventricular unloading. At 64 days of biventricular support, she underwent mitral valve annuloplasty to correct regurgitation under cardiopulmonary bypass. She was consequently weaned from biventricular assist successfully 8 days after mitral surgery (72 days of biventricular support). The patient discharged uneventfully from our hospital and survives at home 12 months after weaning from the ventricular assist devices. Conclusion: Our case and the literature review highlight potential usefulness of aggressive mechanical biventricular support for cardiac recovery in patients with anthracycline-induced cardiomyopathy. Additional valve surgery and neurohormonal medications may be also promising in such patients with cancer, who are contraindicated for heart transplantation.

We report a rare case of retrograde Stanford type A aortic dissection after endovascular repair for complicated Stanford type B aortic dissection. A 45-year-old man presented with a sudden onset of back pain and was transferred to our hospital. Computed tomography demonstrated acute Stanford type B aortic dissection with lower limb ischemia. Emergency endovascular surgery was planned for repair of the Stanford type B aortic dissection. The patient suddenly developed recurrent chest pain 10 days after the initial procedure. Computed tomography revealed retrograde Stanford type A aortic dissection involving the ascending aorta and aortic arch. The patient underwent a successful emergency total aortic arch replacement.

Aortic annular rupture is a potentially fatal complication after transcatheter aortic valve implantation with high mortality. Although it is quite rare and difficult to identify the mechanisms and predictors, prosthesis oversizing and massive calcification of the aortic annulus are thought to be a potential risk of this complication. A case presented here is an aortic annular rupture after transcatheter aortic valve implantation. Although the valve was not oversized, there were 2 severe calcifications of aortic annulus at nearby areas like "twin icicles," thought to be a trigger of this potentially fatal complication.

OBJECTIVES Postoperative acute kidney injury (AKI) is known as a risk factor for death after surgery for Stanford type A acute aortic dissection under hypothermic circulatory arrest. It may also adversely affect long-term survival. We searched for modifiable risk factors for postoperative AKI, focusing on lower body ischaemic time. METHODS We reviewed 191 patients undergoing surgical repair for Stanford type A acute aortic dissection. The distal anastomosis depended on excluding the primary tear location, resulting in ascending/hemiarch (n = 119), partial arch (n = 18) and total arch replacement (n = 54). We defined an increase in the serum creatinine level to ≧2 times the baseline level as AKI. The incidence of AKI was investigated with multivariate analysis of its risk factors. RESULTS Postoperative AKI was observed in 49 patients (26%), 31% of whom required renal replacement therapy. The overall hospital mortality rate was 8.5%. Postoperative AKI, preoperative shock and organ malperfusion were predictors of hospital death. Multivariate stepwise logistic regression analysis identified age, body mass index, preoperative chronic kidney disease and lower body ischaemic time as risk factors for postoperative AKI. CONCLUSIONS Although surgical repair for Stanford type A acute aortic dissection showed favourable results, the incidence of postoperative AKI is still high, closely associated with hospital death. Lower body ischaemic time should be recognized specifically as a modifiable surgical risk factor for postoperative AKI.

Pseudoaneurysm of the ascending aorta is a rare but life- threatening complication after aortic cannulation and cardiovascular surgery, and it has the potential to rupture. We experienced a rare case of recurrence of aneurysm of the ascending aorta 7 years after patch repair of a small aneurysm at an aortic cannulation site. The repaired aorta had been wrapped with a Teflon felt strip during the previous surgery, and the wrapped aorta had become thin with deterioration of the normal structure of the aortic wall.

Background Pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension (CTEPH) is technically demanding. We tried to identify the predictors for short- and long-term outcomes after PEA for CTEPH with aggressive use of pulmonary vasodilators, including epoprostenol sodium. Methods From 2005 to 2013, 122 CTEPH patients, whose preoperative mean pulmonary artery pressure (mPAP) was 47 ± 10 mm Hg and pulmonary vascular resistance was 847 ± 373 dynes/s/cm5, underwent PEA with hypothermic circulatory arrest. Before PEA, all patients underwent pulmonary vasodilator therapy, including epoprostenol sodium of 2 to 6 ng/kg/min. We collected the perioperative and follow-up data retrospectively to identify the predictors for early and late outcomes after PEA. Results In-hospital mortality was 7.4% (n = 9). Predictors for in-hospital death were age older than 65 years and New York Heart Association Functional Classification IV. Among the 113 PEA survivors, the mPAP and pulmonary vascular resistance significantly decreased. After the median follow-up of 6.8 years, the overall survival rates were 91.8%, 89.2%, 89.2%, 89.2%, and 86.1%, and the cardiac events-free rates were 100%, 98.1%, 95.8%, 85.5%, and 49.0%, at 1, 3, 5, 7, and 10 years, respectively, in the Kaplan-Meier model. A multivariate Cox proportional hazard model identified postoperative mPAP exceeding 30 mm Hg as the only predictor for late cardiac events. Conclusions Early and late outcomes of PEA for CTEPH with perioperative aggressive pulmonary vasodilator treatment seem satisfactory. However, residual pulmonary hypertension remains challenging to achieve further improvement of late outcomes.

Cardiovascular manifestations determine the prognosis and survival of patients with Marfan syndrome (MFS). We assessed the early and mid-term outcomes of cardiovascular surgery for this patient population.We conducted a retrospective evaluation of patients with MFS who underwent surgery in our department. The endpoint was the requirement for a second cardiovascular surgery, and death from any cause.From February 2002 to March 2013, we performed 24 surgeries on 13 patients with MFS. At the time of initial surgery, the patients' aged ranged from 19 to 64 years of age (mean 34.7 ± 11.3 years) and included 5 men (38.5 %). Five of 13 initial surgeries (38.5 %) were emergencies. Seven patients (53.8 %) presented with aortic dissection at initial surgery, and one of the remaining six patients suffered from new aortic dissection during follow-up. Eight patients (61.5 %) underwent a second surgery, and a second surgery was not required for 100, 75.0, and 53.6 % of patients at 1, 3, and 5 years, respectively. The mean time interval between the first and the second surgeries was 52.8 ± 28.2 months. No patient died while hospitalized, and three subsequently died from unknown causes. Survival rates were 100, 90.9 and 64.9 % at 3, 5, and 7 years, respectively.Although we obtained satisfactory early outcomes for patients with MFS, there were three late deaths from unknown causes. Therefore, we recommend that patients with MFS should remain under close surveillance.

The frozen elephant trunk (FET) technique allows single-stage extended surgical repair of Stanford type A aortic dissection and has shown promotion of aortic remodeling by maintaining the true lumen flow and facilitating its expansion and by promoting false lumen thrombosis. However, few studies have compared the effectiveness of FET technique, in terms of the downstream aortic remodeling. Between 2005 and 2017, 50 patients underwent total arch replacement for Stanford type A aortic dissection, including that with (n = 22) and without FET technique (n = 28). We compared distal aortic remodeling in patients who underwent total arch replacement with (using a J-Graft open stent graft) or without the technique. The false lumen complete thrombosis rate and the ratio of true lumen area at three levels of the descending aorta were evaluated post operation. In FET group, the diameter and length of the stent graft were 29.0 ± 3.9 mm and 70.9 ± 17.4 mm, respectively. The in-hospital death with and without the FET technique was 0 and 3, respectively, with no late death in both groups. Eight patients (28.6%) only in the non-FET group required additional surgical treatment for downstream aorta. In the FET group, the ratio of true lumen area at the level of bronchial carina and false lumen complete thrombosis rate at the levels of bronchial carina and aortic valve were significantly higher than non-FET group. A more favorable remodeling in the descending aorta was observed in patients who underwent FET associated with a total arch replacement compared to those who underwent total arch replacement alone.

In order to make clear the relationship between the chemical substances concentration and symptom of sick house syndrome, an investigation of 30 sick houses in Japan has been done for 8 years. Chemical substance concentrations show a decrease as the building age increases. However, there are some houses where concentrations increase due to low air change rate, use of moth crystals for clothes and new furniture. Because there was the case where the improvement of indoor air quality has relieved occupant's symptoms, it must be important to take measures such as ventilation frequently, non use of chemical products or use of low chemical products in the long term to treat “SHS”.

We have studied the atomic structure of the surface and interface of VOX/TiO2 (110) by X-ray photoelectron diffraction (XPED). The TiO2 (110) crystal surface was cleaned by cycles of Ar+ sputtering followed by annealing. The TiO2 (110) crystal surface was deoxidized by annealing. Therefore, TiO2 (110) crystal surface was annealed in oxygen atmosphere. Vanadium oxides were deposited by two processes. In process A, vanadium was first deposited on the TiO2 crystal and then oxidized in an O2 atmosphere. In process B, vanadium was deposited in an atmosphere of low-pressure O2. We characterized the VOX ultrathin film grown on the TiO2 (110) surface by low-energy electron diffraction (LEED), X-ray photoelectron spectroscopy (XPS), and XPED. Finally the surface and interface structures of the VOX/TiO2 (110) were clarified by using the multiple scattering cluster model with spherical wave (MSC-SW) method and a reliability factor R(R factor). Copyright © 2008 John Wiley & Sons, Ltd.

Using the Cr La (hv = 572.8 eV) line, which has energy lower than conventional lines, X-ray photoelectron spectroscopy (XPS) and X-ray photoelectron diffraction (XPED) can be used to achieve surface-sensitive and light-element-sensitive measurements. We prepared hexagonal boron nitride (h-BN), which is a light-element material, grown in a monolayer on a Ni (111) surface, and measured h-BN/Ni(111) by XPS/XPED excited by the Al Ka (hv = 1486.6 eV) line and the Cr La line. Finally, we investigated the excitation-energy dependence of the XPED method with respect to energy of the photoelectrons and discuss the effectiveness of the XPED method using Cr La excitation.

In order to determine the factors of origin of Sick House Syndrome (SHS), data of indoor air quality in the sick houses and field survey were collected and carried out respectively, over three summ...

Objective Although clinical studies on pollinosis have been performed employing placebo-controlled double-blind comparative and field techniques, accurate evaluation is difficult because the scattering pollen count and climatic conditions vary between years and regions, leading to a bias in the results. Thus, we prepared a pollen challenge test unit (allergen challenge chamber: ACC) which facilitates quantitative pollen challenge at any time, and, so, the acquisition of objective data. Methods The control of constant conditions and maintenance of specified pollen concentrations in ACC were investigated. In addition, the pollen distribution in ACC was measured while maintaining the level at 10,000 counts/m3. The pollen levels were measured employing the aspiration and Durham methods, and the measured values were compared. Furthermore, whether symptoms are adequately induced in the chamber during the non-cedar pollen-scattering season was investigated in 14 volunteers with cedar pollinosis. Results When the pollen level in ACC was set at 6000 counts/m3 or higher, the rate of variation was ±15%, within the adjustable range, and that of the pollen distribution in the chamber was within ±20%. When the volunteers with cedar pollinosis were exposed to cedar pollen in ACC, pollinosis symptoms were induced, and challenge for 2 consecutive days significantly induced symptoms. Conclusions The temporal and spatial variations of the pollen level in ACC were small, facilitating stable pollen challenge, and pollinosis symptoms were induced in the volunteers with cedar pollinosis. The challenge chamber may be useful to judge the effects of therapy against pollinosis.