Comparison between the mesenteric fixation method (MEFIX) and conventional methods at preventing the occurrence of Petersen's hernia: a study protocol for a multicenter randomized controlled trial.

BACKGROUND: Petersen's hernia, which occurs after Billroth-II (B-II) or Roux-en-Y (REY) anastomosis, can be reduced by defect closure. This study aims to compare the incidence of bowel obstruction above Clavien-Dindo classification grade III due to Petersen's hernia between the mesenteric fixation method and the conventional methods after laparoscopic or robotic gastrectomy. METHODS: This study was designed as prospective, single-blind, non-inferiority randomized controlled multicenter trial in Korea. Patients with histologically diagnosed gastric cancer of clinical stages I, II, or III who underwent B-II or REY anastomosis after laparoscopic or robotic gastrectomy are enrolled in this study. Participants who meet the inclusion criteria are randomly assigned to two groups: a CLOSURE group that underwent conventional Petersen's defect closure method and a MEFIX group that underwent the mesenteric fixation method. The primary endpoint is the number of patients who underwent surgery for bowel obstruction caused by Petersen's hernia within 3 years after laparoscopic or robotic gastrectomy. DISCUSSION: This trial is expected to provide high-level evidence showing that the MEFIX method can quickly and easily close Petersen's defect without increased postoperative complications compared to the conventional method. TRIAL REGISTRATION: ClinicalTrials.gov NCT05105360. Registered on November 3, 2021.

Prediction of the possibility of laparoscopic reduction of Petersen's hernia after gastrectomy: multicenter observational cohort study.

INTRODUCTION: Petersen's hernia (PH) is a potentially fatal complication of bowel infarction that is difficult to treat by laparoscopic reduction. AIM: To define predictive computed tomography (CT) profiles to identify PH patients who would be suitable for laparoscopic reduction by a comparative analysis between patients treated by laparoscopic and open reduction. MATERIAL AND METHODS: We retrospectively collected the clinical data of patients (n = 28) who underwent PH reduction surgery after minimally invasive gastrectomy for gastric cancer in the period 2015-2018 at four training hospitals. We examined the preoperative CT scans to identify the indications for laparoscopic PH reduction. RESULTS: We compared the laparoscopic reduction group (laparoscopic group, n = 15) and the open reduction group (open group, n = 13). Patients in the laparoscopic group were younger (55.7 ±10.4) than those in the open group (69.3 ±9.1), but there were no differences in clinical or laboratory findings. We found that there were two CT profiles with significant differences between the open and laparoscopic groups: superior mesenteric vein (SMV) narrowing and small bowel dilation. We found that small bowel dilatation was an independent factor on multivariate analysis for laparoscopic PH reduction. CONCLUSIONS: We found that small bowel dilatation is the most important CT profile for identifying PH patients contraindicated for laparoscopic reduction. Despite the retrospective design of this study, these CT profiles are expected to define the scope of laparoscopic reduction in PH patients and to establish indications for the laparoscopic approach.

A comparison of postoperative outcomes after open and laparoscopic reduction of Petersen's Hernia: a multicenter observational cohort study.

BACKGROUND: The aim of this multicenter cohort study was to compare the clinical courses between open and laparoscopic Petersen's hernia (PH) reduction. METHOD: We retrospectively collected the clinical data of patients who underwent PH repair surgery after gastrectomy for gastric cancer from 2015-2018. Forty patients underwent PH reduction operations that were performed by six surgeons at four hospitals. Among the 40 patients, 15 underwent laparoscopic PH reduction (LPH), and 25 underwent open PH reduction (OPH), including 4 patients who underwent LPH but required conversion to OPH. RESULTS: We compared the clinical factors between the LPH and OPH groups. In the clinical course, we found no differences in operation times or intraoperative bowel injury, morbidity, or mortality rates between the two groups (p > 0.05). However, the number of days on a soft fluid diet (OPH vs. LPH; 5.8 vs. 3.7 days, p = 0.03) and length of hospital stay (12.6 vs. 8.2 days, p = 0.04) were significantly less in the LPH group than the OPH group. Regarding postoperative complications, the OPH group had a case of pneumonia and sepsis with multi-organ failure, which resulted in mortality. In the LPH group, one patient experienced recurrence and required reoperation for PH. CONCLUSION: Laparoscopic PH reduction was associated with a faster postoperative recovery period than open PH reduction, with a similar incidence of complications. The laparoscopic approach should be considered an appropriate strategy for PH reduction in selected cases.

Laparoscopy-assisted versus Open D2 Distal Gastrectomy for Advanced Gastric Cancer: Results From a Randomized Phase II Multicenter Clinical Trial (COACT 1001).

OBJECTIVE: This randomized, phase II, multicenter clinical trial was conducted to evaluate the feasibility of laparoscopy-assisted distal gastrectomy (LADG) with D2 lymph node dissection compared with open distal gastrectomy (ODG) for the treatment of advanced gastric cancer (AGC). SUMMARY OF BACKGROUND DATA: D2 lymph node dissection has been accepted as standard treatment for AGC. Although LADG is widely performed in early gastric cancer (EGC), the feasibility of LADG in AGC has not been proven yet. METHODS: Patients with cT2-T4a and cN0-2 (AJCC 7 staging system) distal gastric cancer were randomly but not blindingly assigned to LADG or ODG groups using fixed block sizes with a 1:1 allocation ratio. The primary endpoint was the noncompliance rate of the lymph node dissection, which was used to evaluate feasibility. Secondary endpoints included 3-year disease-free survival (DFS), 5-year overall survival, complications, and surgical stress response. RESULTS: Between June 2010 and October 2011, 204 patients enrolled and underwent either LADG (n = 105) or ODG (n = 99). Of these, 196 patients (100 in LADG and 96 in ODG) were included in the intention-to-treat analysis. There were no significant differences in the overall noncompliance rate of lymph node dissection between LADG and ODG groups (47.0% and 43.2%, respectively; P = 0.648). In the subgroup analysis, the noncompliance rate in the LADG group was significantly higher than the ODG group for clinical stage III disease (52.0% vs 25.0%, P = 0.043). No difference was found in the 3-year DFS rate between the groups (LADG, 80.1%; ODG, 81.9%; P = 0.448). Differences in postoperative complication rates and surgical stress response were found to be insignificant between the 2 arms. CONCLUSIONS: LADG was feasible for AGC treatment based on the noncompliance rate of D2 lymph node dissection. Subgroups analysis data suggest that further studies are needed for stage III gastric cancer.

Postoperative oral nutritional supplementation after major gastrointestinal surgery: a randomized controlled clinical trial.

BACKGROUND AND OBJECTIVES: This study aimed to evaluate the efficacy of post-operative oral nutrition supplementation after major gastrointestinal surgery. METHODS AND STUDY DESIGN: A prospective randomized controlled trial was conducted to evaluate 174 subjects who were discharged within 2 weeks after major gastrointestinal surgery. The subjects in the study group were prescribed 400 ml/day of Encover® from the day of discharge for 8 weeks, but no supplementation was allowed in the control group. The primary endpoint was the weight loss rate at 8 weeks after discharge compared with the pre-operative weight, and the secondary endpoints included changes in body weight, body mass index, Patient-Generated Subjective Global Assessment score/grade, hematological/ biochemical parameters, and adverse events evaluated at 2, 4, and 8 weeks after discharge. RESULTS: The weight loss rate at 8 weeks after discharge did not differ between two groups (4.23±5.49% vs 4.80±4.84%, p=0.481). The total lymphocyte count, the level of total cholesterol, total protein, and albumin were significantly higher in the study group after discharge. Diarrhea was the most frequent adverse event, and the incidence of adverse events with a severity score of >=3 did not differ between groups (2.3% vs 1.2%). CONCLUSIONS: The utility of routine oral nutritional support after major gastrointestinal surgery was not proven in terms of weight loss at 8 weeks after discharge. However, it can be beneficial for early recovery of biochemical parameters.

Minimal Resection of Jejuna Dieulafoy's Lesion Using an Intraoperative Fluoroscopic Localization of the Metallic Coils Used in Angiography.

Dieulafoy's lesions of the Jejunum are extremely rare. Therefore, localization of lesions is very difficult due to their small size and tendency of occasional bleeding. However, it is important to mention the location of the Dieulafoy's lesions to prevent excessive intestinal resections or, even worse, resection of the normal intestine. We report a case of preoperative localization of a Dieulafoy's lesion embolized by a metallic coil that allows a surgeon to accurately identify the bleeding, permitting a minimally invasive surgical treatment. A 25-year-old man presented with massive hematochezia. There was no definite bleeding focus on the upper gastrointestinal endoscopy and colonoscopy. An angiography found a persistent extravasation of the contrast media at the end of straight artery of the mid-jejunal branch, around the terminal ileum, embolized with metallic coils immediately. The combination of embolized metallic coils and intraoperative fluoroscopy allowed accurate identification and minimal laparotomy. Consequently, a highly selective and minimal resection of the jejunum containing the dieulafoy lesion was possible without any postoperative complications.

Laparoscopic Partial Fundoplication in Case of Gastroesophageal Reflux Disease Patient with Absent Esophageal Motility.

The surgical indications for the treatment of gastroesophageal reflux disease (GERD) in patients with esophageal motility disorders have been debated. We report a case of antireflux surgery performed in a patient with absent esophageal motility as categorized by the Chicago classification (2011). A 54-year-old man underwent laparoscopic Toupet fundoplication due to apparent GERD and desire to discontinue all medications. After surgery, his subjective symptoms improved. Furthermore, objective findings including manometry and 24-hour pH-metry also improved. In our experience, antireflux surgery can improve GERD symptoms patients, even with absent esophageal motility.

Correlations of Human Epithelial Growth Factor Receptor 2 Overexpression with MUC2, MUC5AC, MUC6, p53, and Clinicopathological Characteristics in Gastric Cancer Patients with Curative Resection.

Background. The purpose of this study was to evaluate the relationships between HER2 overexpression in the tumor and MUC2, MUC5AC, MUC6, and p53 status and clinicopathological characteristics of gastric cancer patients. Methods. This retrospective study included 282 consecutive patients with gastric cancer who underwent surgery at the Kosin University Gospel Hospital between April 2011 and December 2012. All tumor samples were examined for HER2 expression by immunohistochemistry (IHC) and MUC2, MUC5AC, MUC6, and p53 expression by staining. A retrospective review of the medical records was conducted to determine the correlation between the presence of HER2 overexpression and clinicopathological factors. Results. The HER2-positive rate was 18.1%. Although no association was found between HER2 expression and MUC5AC, the expression of MUC2, MUC6, and p53 was significantly correlated with HER2 positivity, respectively (P = 0.004, 0.037, 0.002). Multivariate analysis revealed that HER2 overexpression and nodal status were independent prognostic factors. Conclusions. HER2 overexpression in gastric carcinoma is an independent poor prognostic factor.

Correlation between HER2 Overexpression and Clinicopathological Characteristics in Gastric Cancer Patients Who Have Undergone Curative Resection.

PURPOSE: At present, a human epidermal growth factor receptor 2 (HER2)-based concept of tumor biology has been established, and trastuzumab (Herceptin®; Genentech/Roche, San Francisco, CA, USA), a monoclonal humanized antibody directed against HER2, is a pivotal agent for the management of HER2 positive (HER2+) metastatic breast cancer. It is also known that HER2 has a predictive value in gastric cancer; however, its association with the prognosis of this disease remains uncertain. The purpose of this study was to evaluate both the relationship between HER2 overexpression in the tumors of gastric cancer patients, and the prognosis of these patients who have had curative resection. MATERIALS AND METHODS: A total of 139 consecutive patients with gastric cancer who underwent surgery at the Kosin University Gospel Hospital between October 2011 and March 2012 were included in this retrospective study. All tumor samples were examined for HER2 expression by immunohistochemistry. A retrospective review of the medical records was conducted to determine the correlation between the presence of HER2 overexpression and clinicopathological factors. RESULTS: The HER2+ rate was 15.1%. HER2 overexpression was associated with histological grade (P=0.044) and Lauren classification (P=0.036). There was no significant difference in the 2-year overall survival between HER2+ and HER2- patients (P=0.396). Multivariate analysis showed that HER2 was not an independent prognostic factor. CONCLUSIONS: HER2 overexpression in tumors was associated with histological grade and Lauren classification in gastric cancer patients with curative resection. However, HER2 was not an independent prognostic factor for gastric cancer in our study.

Laparoscopy Assisted versus Open Distal Gastrectomy with D2 Lymph Node Dissection for Advanced Gastric Cancer: Design and Rationale of a Phase II Randomized Controlled Multicenter Trial (COACT 1001).

PURPOSE: Laparoscopy-assisted distal gastrectomy for early gastric cancer has gained acceptance and popularity worldwide. However, laparoscopy-assisted distal gastrectomy for advanced gastric cancer is still controversial. Therefore, we propose this prospective randomized controlled multi-center trial in order to evaluate the safety and feasibility of laparoscopy assisted D2-gastrectomy for advanced stage gastric cancer. MATERIALS AND METHODS: Patients undergoing distal gastrectomy for advanced gastric cancer staged cT2/3/4 cN0/1/2/3a cM0 by endoscopy and computed tomography are eligible for enrollment after giving their informed consent. Patients will be randomized either to laparoscopy-assisted distal gastrectomy or open distal gastrectomy. Sample size calculation revealed that 102 patients are to be included per treatment arm. The primary endpoint is the non-compliance rate of D2 dissection; relevant secondary endpoints are three-year disease free survival, surgical and postoperative complications, hospital stay and unanimity rate of D2 dissection evaluated by reviewing the intraoperative video documentation. DISCUSSION: Oncologic safety is the major concern regarding laparoscopy-assisted distal gastrectomy for advanced gastric cancer. Therefore, the non-compliance rate of clearing the N2 area was chosen as the most important parameter for the technical feasibility of the laparoscopic procedure. Furthermore, surgical quality will be carefully reviewed, that is, three independent experts will review the video records and score with a check list. For a long-term result, disease free survival is considered a secondary endpoint for this trial. This study will offer promising evidence of the feasibility and safety of Laparoscopy-assisted distal gastrectomy for advanced gastric cancer. TRIAL REGISTRATION: NCT01088204 (international), NCCCTS-09-448 (Korea).

[Nutritional assessment and perioperative nutritional support in gastric cancer patients].

Weight loss and malnutrition are common in cancer patients. Although weight loss is predominantly due to loss of fat mass, the morbidity risk is given by the decrease in muscle mass. The assessment of nutritional status is essential for a diagnosis of nutritional compromise and required for the multidisciplinary approach. Subjective global assessment (SGA) is made by the patients nutritional symptoms and weight loss. The objective assessment, a significant weight loss (>10%) for 6 months is considered an indicator of nutritional deficiency. The mean body index, body fat mass and body protein mass are decreased as cancer stage increases. The biochemical data of albumin, cholesterol, triglyceride, Zn, transferrin, total lymphocyte count are decreased in advanced cancer stage. Daily energy intake, cabohyderate and Vit B1 intake is decreased according to cancer stage. The patients are divided into three groups according to SGA. The three groups showed a significant difference in body weight, 1 month weight loss%, 6 month weight loss%, body mass index, mid arm circumference, albumin, energy intake, as well as carbohyderate intake protein and energy malnutrition. Nutritional assessment is of great importance because undernutrition has been shown to be associated with increase in stomach cancer associated morbidity and mortality. The authors concluded that nutritional assessment should be done in cancer patients preoperatively, and with adequate nutritional support, the morbidity and mortality would be decreased.

18F-2-Deoxy-2-Fluoro-D-Glucose Positron Emission Tomography: Computed Tomography for Preoperative Staging in Gastric Cancer Patients.

PURPOSE: The use of 18F-2-deoxy-2-fluoro-D-glucose positron emission tomography-computed tomography as a routine preoperative modality is increasing for gastric cancer despite controversy with its usefulness in preoperative staging. In this study we aimed to determine the usefulness of preoperative positron emission tomography-computed tomography scans for staging of gastric cancer. MATERIALS AND METHODS: We retrospectively analyzed 396 patients' positron emission tomography-computed tomography scans acquired for preoperative staging from January to December 2009. RESULTS: The sensitivity of positron emission tomography-computed tomography for detecting early gastric cancer was 20.7% and it was 74.2% for advanced gastric cancer. The size of the primary tumor was correlated with sensitivity, and there was a positive correlation between T stage and sensitivity. For regional lymph node metastasis, the sensitivity and specificity of the positron emission tomography-computed tomography were 30.7% and 94.7%, respectively. There was no correlation between T stage and maximum standardized uptake value or between tumor markers and maximum standardized uptake value. Fluorodeoxyglucose uptake was detected by positron emission tomography-computed tomography in 24 lesions other than the primary tumors. Among them, nine cases were found to be malignant, including double primary cancers and metastatic cancers. Only two cases were detected purely by positron emission tomography-computed tomography. CONCLUSIONS: Positron emission tomography-computed tomography could be useful in detecting metastasis or another primary cancer for preoperative staging in gastric cancer patients, but not for T or N staging. More prospective studies are needed to determine whether positron emission tomography-computed tomography scans should be considered a routine preoperative imaging modality.

A case of metastatic leptomeningeal carcinomatosis from early gastric carcinoma.

Metastatic leptomeningeal carcinomatosis is estimated to occur in 3% to 8% of solid carcinomas. The most common causes of leptomeningeal carcinomatosis are breast cancer, lung cancer and malignant melanoma. Leptomeningeal carcinomatosis associated with gastric cancer, especially in its early stages, is exceedingly rare. Its presenting symptoms include headache, nausea and seizures. In this report, we describe a case of leptomeningeal metastasis that presented with early-stage gastric cancer. A 67-year-old woman with a history of early-stage gastric cancer in remission was admitted to our hospital with 3 days of headache and nausea. Her gastric cancer had been treated 29 months prior to presentation by a radical subtotal gastrectomy with a Billroth I anastomosis. She had an uneventful recovery until she was diagnosed with metastases to the left axilla and neck 26 months after surgery. Her presenting symptoms of headache and nausea prompted cytologic examination of the cerebrospinal fluid and measurement of tumor markers, which revealed metastatic leptomeningeal carcinomatosis from her gastric cancer. This report aims to raise awareness of the possibility that even early-stage gastric cancer can lead to leptomeningeal carcinomatosis.

Laparoscopy-assisted distal gastrectomy for early gastric cancer in the elderly.

PURPOSE: With an increase in life expectancy, more elderly patients are presenting with gastric cancer. As a result it is yet be resolved whether laparoscopy assisted distal gastrectomy is a suitable treatment for elderly patients with early gastric cancer. This study retrospectively compared surgical outcomes of laparoscopy assisted distal gastrectomy between elderly and nonelderly patients with gastric cancer. MATERIALS AND METHODS: The study group was comprised of 316 patients who underwent laparoscopy assisted distal gastrectomy between April 2005 and December 2010. Of these patients, 93 patients whose ages were 65 years or more were compared with 223 patients who were younger. RESULTS: There were no differences in the short term outcome or minor complication rate between the elderly patients and the nonelderly patients. The hospital stay was significantly longer and the major complication rate was significantly higher for the elderly patients compared with nonelderly patients. CONCLUSIONS: Laparoscopy assisted distal gastrectomy for early gastric cancer in the elderly patients had comparable operation time and blood loss with the nonelderly group. However, the safety and advantage of laparoscopy assisted distal gastrectomy in the elderly patients need to be further studied in higher volume trials.

Amylase, lipase, and volume of drainage fluid in gastrectomy for the early detection of complications caused by pancreatic leakage.

PURPOSE: Pancreatic leakage is a serious complication of gastrectomy due to stomach cancer. Therefore, we analyzed amylase and lipase concentrations in blood and drainage fluid, and evaluated the volume of drainage fluid to discern their usefulness as markers for the early detection of serious pancreatic leakage requiring reoperation after gastrectomy. METHODS: From January 2001 to December 2007, we retrospectively analyzed data from 24,072 patient samples. We divided patients into two groups; 1) complications with pancreatic leakage (CG), and 2) no complications associated with pancreatic leakage (NCG). Values of amylase and lipase in the blood and drainage fluid, volume of the drainage fluid, and relationships among the volumes, amylase values, and lipase values in the drainage fluid were evaluated, respectively in the two groups. RESULTS: The mean amylase values of CG were significantly higher than those of NCG in blood and drainage fluid (P < 0.05). For lipase, statistically significant differences were observed in drainage fluid (P < 0.05). The mean volume (standard deviation) of the drained fluid through the tube between CG (n = 22) and NCG (n = 236) on postoperative day 1 were 368.41 (266.25) and 299.26 (300.28), respectively. There were no statistically significant differences between the groups (P = 0.298). There was a correlation between the amylase and lipase values in the drainage fluid (r = 0.812, P = 0.000). CONCLUSION: Among postoperative amylase and lipase values in blood and drainage fluid, and the volume of drainage fluid, the amylase in drainage fluid was better differentiated between CG and NCG than other markers. The volume of the drainage fluid did not differ significantly between groups.

Prediction of nephrotoxicity induced by cisplatin combination chemotherapy in gastric cancer patients.

AIM: To evaluate the treatment options for nephrotoxicity due to cisplatin combination chemotherapy. METHODS: We retrospectively reviewed patients who had received cisplatin combination chemotherapy for gastric cancer between January 2002 and December 2008. We investigated patients who had shown acute renal failure (ARF), and examined their clinical characteristics, laboratory data, use of preventive measures, treatment cycles, the amount of cisplatin administered, recovery period, subsequent treatments, and renal status between the recovered and unrecovered groups. RESULTS: Forty-one of the 552 patients had serum creatinine (SCR) levels greater than 1.5 mg/dL. We found that pre-ARF SCR, ARF SCR, and ARF glomerular filtration rates were significantly associated with renal status post-ARF between the two groups (P = 0.008, 0.026, 0.026, respectively). On the receiver operating characteristic curve of these values, a 1.75 mg/dL ARF SCR value had 87.5% sensitivity and 84.8% specificity (P = 0.011). CONCLUSION: Cessation or reduction of chemotherapy should be considered for patients who have an elevation of SCR levels during cisplatin combination chemotherapy.

[Individualized surgery for gastric cancer].

Recently, tailored and multidisciplinary treatment of gastric cancer was emerging in the field of clinical oncology. Gastric cancer is the most frequently diagnosed cancer in Korea. Surgery is the only possible curative procedure, and extensive gastrectomy and D2 lymph node dissection has been accepted as standard treatment in all gastric cancer patients until recently. In early gastric cancer, many researchers established the indications of limited surgery including endoscopic mucosal resection based on various well-collected retrospective data. Limited surgery and minimally invasive surgery contribute to quality of life in gastric cancer patients. In advanced gastric cancer, eastern surgeons believe that D2 lymph node dissection is standard treatment if done by credential surgeons in specialized centers despite of different opinion of western surgeon. In addition, adjuvant chemotherapy after good local control by D2 dissection has gained survival benefit rather than D2 dissection alone in randomized trials. In conclusion, present confronted issue is to establish tailored treatments of individualized patients through extent of disease in gastric cancer patients.

Laparoscopy-assisted distal gastrectomy for early gastric cancer and laparoscopic cholecystectomy for gallstone with situs inversus totalis: a case report.

We report our case of laparoscopy-assisted distal gastrectomy with D1 + ß lymph node dissection for a patient with early gastric cancer and laparoscopic cholecystectomy for gallstone with situs inversus totalis. A superficial elevated lesion was found on the lesser curvature of the antrum. The preoperative diagnosis was cStage IA (cT1, cN0, cH0, cP0, cM0). A 1 cm-sized gallstone was found in the fundus through upper abdominal ultrasound. A laparoscopy-assisted distal gastrectomy with standard D2 lymph node dissection for early gastric cancer and laparoscopic cholecystectomy was successfully performed by not shifting the monitor to the left and right and not changing operator's position without additional blood loss and time. The number of retrieved lymph nodes was 36. We have not found any abnormal course of blood vessels except for the right/left inversion. Billroth I reconstruction was performed through end-to-side anastomosis. Based on a histopathological examination, a 1.5 × 1.5 cm, submucosal (sm3), moderately differentiated adenocarcinoma (pT1, pN0, sH0, sP0, sM0, stage IA) was diagnosed. The postoperative course was favorable and the patient was discharged on postoperative day 7.

Design and application of an inertial impactor in combination with an ATP bioluminescence detector for in situ rapid estimation of the efficacies of air controlling devices on removal of bioaerosols.

We proposed a rapid method to estimate the efficacies of air controlling devices in situ using ATP bioluminescence in combination with an inertial impactor. The inertial impactor was designed to have 1 mum of cutoff diameter, and its performance was estimated analytically, numerically, and experimentally. The proposed method was characterized using Staphylococcus epidermidis, which was aerosolized with a nebulizer. The bioaerosol concentrations were estimated within 25 min using the proposed method without a culturing process, which requires several days for colony formation. A linear relationship was obtained between the results of the proposed ATP method (RLU/m(3)) and the conventional culture-based method (CFU/m(3)), with R(2) 0.9283. The proposed method was applied to estimate the concentration of indoor bioaerosols, which were identified as a mixture of various microbial species including bacteria, fungi, and actinomycetes, in an occupational indoor environment, controlled by mechanical ventilation and an air cleaner. Consequently, the proposed method showed a linearity with the culture-based method for indoor bioaerosols with R(2) 0.8189, even though various kinds of microorganisms existed in the indoor air. The proposed method may be effective in monitoring the changes of relative concentration of indoor bioaerosols and estimating the effectiveness of air control devices in indoor environments.