Usefulness of LacdiNAc-glycosylated Prostate-specific Antigen Density for Predicting Pathological Findings of Magnetic Resonance Imaging-transrectal Ultrasound Fusion Image-guided Prostate Biopsy for the Patients With Highest Prostate Imaging Reporting and Data System Category ≥3.

PURPOSE: This study aimed to evaluate the usefulness of the LDN-PSA (LacdiNAc-glycosylated-prostate specific antigen) in detecting clinically significant prostate cancer in patients suspected of having clinically significant prostate cancer on multiparametric magnetic resonance imaging. MATERIALS AND METHODS: Patients with prostate specific antigen levels ranging between 3.0 ng/mL and 20 ng/mL and suspicious lesions with PI-RADS (Prostate Imaging-Reporting and Data System) category ≥3 were included prospectively. The LDN-PSA was measured using an automated 2-step Wisteria floribunda agglutinin lectin-anti-prostate specific antigen antibody sandwich immunoassay. RESULTS: Two hundred four patients were included. Clinically significant prostate cancer was detected in 105 patients. On multivariable logistic regression analysis, prostate specific antigen density (OR 1.61, P = .010), LDN-PSAD (OR 1.04, P = .012), highest PI-RADS category (3 vs 4, 5; OR 14.5, P < .0001), and location of the lesion with highest PI-RADS category (transition zone vs peripheral zone) (OR 0.34, P = .009) were significant risk factors for detecting clinically significant prostate cancer. Among the patients with the highest PI-RADS category 3 (n=113), clinically significant prostate cancer was detected in 28 patients. On multivariable logistic regression analysis to predict the detection of clinically significant prostate cancer in patients with the highest PI-RADS category 3, age (OR 1.10, P = .026) and LDN-PSAD (OR 1.07, P < .0001) were risk factors for detecting clinically significant prostate cancer. CONCLUSIONS: LDN-PSAD would be a biomarker for detecting clinically significant prostate cancer in patients with prostate specific antigen levels ≤20 ng/mL and suspicious lesions with PI-RADS category ≥3. The use of LDN-PSAD as an adjunct to the use of prostate specific antigen levels would avoid unnecessary biopsies in patients with the highest PI-RADS category 3. Multi-institutional studies with large population are recommended.

Coronary arterial repair in patients with stable angina pectoris or acute coronary syndrome after ultrathin biodegradable polymer sirolimus-eluting stent implantation at 1-year follow-up by coronary angioscopy.

BACKGROUND: Imaging modality-based evidence is limited that compares the extent of coronary arterial repair after percutaneous coronary intervention between patients with stable angina pectoris (SAP) and those with acute coronary syndrome (ACS). METHODS: Between December 2018 and November 2021, a single-center, nonrandomized, observational study was conducted in 92 patients with SAP (n = 42) or ACS (n = 50), who were implanted with Orsiro sirolimus-eluting stent (O-SES) providing a hybrid (active and passive) coating and underwent 1-year follow-up by coronary angioscopy (CAS) after implantation. CAS assessed neointimal coverage (NIC), maximum yellow plaque (YP), and mural thrombus (MT). RESULTS: Baseline clinical characteristics were comparable between the SAP and ACS groups. The follow-up periods were comparable between the two groups (390.1 ± 69.9 vs. 390.6 ± 65.7 days, p = 0.99). The incidences of MT at 1 year after implantation were comparable between the two groups (11.4% vs. 11.1%, p = 0.92). The proportions of "Grade 1" in dominant NIC grades were highest in both groups, and the proportions of maximum YP grades and MT were comparable between the two groups. CONCLUSION: O-SES-induced coronary arterial repair at the site of stent implantation, irrespective of the types of coronary artery disease.

Endovascular treatment of postoperative hemorrhage after pancreatectomy: a retrospective study.

BACKGROUND: Ruptured aneurysm is a serious complication of distal pancreatectomy (DP) or pancreatoduodenectomy (PD) that can be life-threatening if not treated promptly. This study aimed to examine the efficacy of a Viabahn stent graft for stopping bleeding after pancreatectomy. METHODS: Between April 2016 and June 2022, we performed 245 pancreatectomies in our institution. Six patients experienced postoperative bleeding and underwent endovascular treatment. RESULTS: All six cases of bleeding occurred post-PD (3.7%). The bleeding was from gastroduodenal artery (GDA) pseudoaneurysms in three patients, and Viabahn stent grafts were inserted. All three patients did not show liver function abnormalities or hepatic blood flow disorders. One patient with a Viabahn stent graft experienced rebleeding, which required further management to obtain hemostasis. Of the six cases in which there was hemorrhage, one case of bleeding from the native hepatic artery could not be managed. CONCLUSIONS: Using the Viabahn stent graft is an effective treatment option for postoperative bleeding from GDA pseudoaneurysms following PD. In most cases, using this device resulted in successful hemostasis, without observed abnormalities in hepatic function or blood flow.

Vessel Occlusion using Hydrogel-Coated versus Nonhydrogel Embolization Coils in Peripheral Arterial Applications: A Prospective, Multicenter, Randomized Trial.

PURPOSE: To evaluate the safety and effectiveness of hydrogel-coated coils for vessel occlusion in the body trunk. MATERIALS AND METHODS: A total of 77 patients with various peripheral vascular lesions, treatable by embolization with coils, were randomized (hydrogel group, n = 38; nonhydrogel group, n = 39). In the hydrogel group, embolization of the target vessel was conducted using 0.018-inch hydrogel-coated coils (AZUR 18; Terumo Medical Corporation, Tokyo, Japan) with or without bare platinum coils. The nonhydrogel group received both bare platinum coils and fibered coils without the use of hydrogel-coated coils. RESULTS: Complete target vessel occlusion was accomplished in 36 patients in the hydrogel group and 37 patients in the nonhydrogel group. No major adverse events were observed in either group. The median number of coils/vessel diameter and the median total coil length/vessel diameter were significantly larger in the nonhydrogel group than in the hydrogel group (P = .005 and P = .004, respectively). The median embolization length was significantly longer in the nonhydrogel group (31.95 mm) than in the hydrogel group (23.43 mm) (P = .002). If no expansion was assumed, the median packing density in the hydrogel group was 44.9%, which was similar to that in the nonhydrogel group (46.5%) (P = .79). With full expansion assumed, the median packing density in the hydrogel group was 125.7%. CONCLUSIONS: Hydrogel-coated coils can be safely used for peripheral vascular coil embolization, and hydrogel-coated and conventional coils in combination allow for a shorter embolization segment and shorter coil length.

Fabrication of Gd-DOTA-functionalized carboxylated nanodiamonds for selective MR imaging (MRI) of the lymphatic system.

Magnetic resonance imaging (MRI) contrast agents with the particle diameter of around 3-10 nm hold the potential to be selectively uptaken by lymphatic vessels and be filtered in the kidney for final excretion. However, there are no existing MRI contrast agents based on gadolinium (Gd) complexes within the size of this range, and thus the selective imaging of the lymphatic system has not yet been achieved. In our previous report, we succeeded in fabricating nano-scale MRI contrast agents by complexing ordinary contrast agents (Gd-diethylenetriaminepentaacetic acid (DTPA)) with carboxylated nanodiamond (CND) particles to conquer this problem. However, DTPA has recently been reported to release Gd ions in the course of time, leading to the potential danger of severe side effects in the human body. In this study, we utilized cyclic-chained DOTA as an alternative chelating material for DTPA to fabricate CND-based MRI contrast agents for the selective lymphatic imaging. The newly fabricated contrast agents possessed the diameter ranging from 3 to 10 nm in distilled water and serum, indicating that these particles can be selectively uptaken by lymphatic vessels and effectively filtered in the kidney. Furthermore, the DOTA-applied CND contrast agents exhibited stronger MRI visibility in water and serum compared to DTPA-applied CND contrast agents. These results indicate that DOTA-applied CND contrast agents are promising materials for the selective MR imaging of lymphatic systems.

Reduction of severe acute respiratory syndrome coronavirus-2 infectivity by admissible concentration of ozone gas and water.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is causing the global coronavirus disease 2019 (COVID-19) pandemic. Because complete elimination of SARS-CoV-2 appears difficult, decreasing the risk of transmission is important. Treatment with 0.1 and 0.05 ppm ozone gas for 10 and 20 hr, respectively, decreased SARS-CoV-2 infectivity by about 95%. The magnitude of the effect was dependent on humidity. Treatment with 1 and 2 mg/L ozone water for 10 s reduced SARS-CoV-2 infectivity by about 2 and 3 logs, respectively. Our results suggest that low-dose ozone, in the form of gas and water, is effective against SARS-CoV-2.

Analysis of oncological outcomes of whole-gland therapy with high-intensity focused ultrasound for localized prostate cancer in clinical and technical aspects: a retrospective consecutive case-series analysis with a median 5-year follow-up.

PURPOSE: This study aimed to analyze technical and clinical factors related to oncological outcomes in patients with localized prostate cancer (PC) who were treated with whole-gland high-intensity focused ultrasound (HIFU). MATERIALS AND METHODS: From 2007-2014, patients diagnosed with localized PC who underwent whole-gland HIFU were consecutively included retrospectively. Biochemical failure was defined according to the Phoenix ASTRO guidelines. The relationship between oncological outcomes and technical and clinical factors was evaluated. RESULTS: The study cohort included 428 patients. The median age was 67 years, and the median prostate-specific antigen level was 7.61 ng/mL. Patient risk classifications were low (n = 102), intermediate (n = 240), and high (n = 86). Biochemical disease-free survival rates of patients with HIFU for localized PC in the total, low-, intermediate-, and high-risk groups according to D'Amico risk groups over a median follow-up period of 5 years (range 9-144) were 68.4%, 80.4%, 65.6%, and 61.6%, respectively. In multivariate logistic regression analyses to predict biochemical failure of the treatment, neoadjuvant hormonal therapy (NHT) in the high-risk group (OR 0.225, p = 0.015), and compression method in the low- (OR 0.178, p = 0.030), intermediate- (OR0.291, p < 0.0001), and high-risk (OR 0.316, p = 0.049) groups were significant factors that reduced the risk of biochemical failure after treatment. There were no significant differences in complications between patients treated with compression and those treated conventionally. CONCLUSIONS: NHT may potentially improve oncological outcomes for patients in the high-risk group, and compression methods can improve the oncological outcomes of whole-gland therapy with HIFU.

Snuff box radial access in transcatheter arterial embolization for unruptured renal angiomyolipoma.

OBJECTIVE: We report the first three cases in which the feasibility and safety of the left snuff box radial access in transcatheter arterial embolization (TAE) for unruptured renal angiomyolipoma (AML) were evaluated. MATERIAL AND METHODS: Three patients with unruptured renal AMLs underwent TAE via the left snuff box radial artery. We retrospectively evaluated the characteristics of the AMLs, technical success rate, clinical success rate, and complications. Technical success and clinical success were defined as successful insertions of microballoon catheters selectively via the left distal radial artery into all intended arteries in a treatment session and shrinkage of tumor size as evaluated by CT or MRI after the procedure, respectively. RESULTS: The median size of the renal AMLs was 49 mm. TAE was successfully performed in all cases and all feeding arteries were successfully selected with a microballoon catheter through the left snuff box radial artery. The median amount of the mixture of ethanol and Lipiodol was 1.8 mL. Tumor shrinkage was confirmed in all with a median follow-up period of 6 months. The clinical success rate was 100%. No major complications occurred. CONCLUSION: The left snuff box access in TAE for an unruptured renal AML is safe and feasible.

The approach of scratch-imprint cytology: Is it an alternative to frozen section for intraoperative assessment of pulmonary lesions?

To address the diagnostic performance of scratch-imprint cytology (SIC), in this study we compared intraoperative diagnoses of pulmonary lesions between SIC and frozen section histology (FSH) for accuracy with respect to the final pathological diagnosis. We histologically divided 206 pulmonary lesions (resected surgically) into two groups (benign and malignant) and compared each intraoperative diagnosis by SIC and FSH with the final pathological diagnoses. We also examined the radiological existence of pure ground-glass opacity (GGO) nodules in each group. The diagnostic sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 91.5%, 100%, 100%, 63.6%, and 92.6%, respectively for SIC, and 98.2%, 100%, 100%, 92.1% and 98.5%, respectively, for FSH. Thus, we concluded that diagnosis by SIC is reliable for malignancy, but not for benign lesions. All pure GGO nodules (19; 9.2%) were noninfectious and malignant with a high accuracy of FSH diagnosis (100%), in comparison with those of low accuracy with a SIC diagnosis (57.9%). SIC can be an appropriate intraoperative diagnostic tool where multiple cytotechnologists observe intraoperative SIC preparations scratched evenly across the whole lesion including the peripheral area of the mass.

Detection of Shunting Into Pulmonary Artery on Multidetector Row Computed Tomography Arteriography Before Bronchial Arterial Embolization: A Preliminary Study.

OBJECTIVE: The aim of this study was to investigate the diagnostic performance of detecting systemic arterial pulmonary circulation shunts on multidetector row computed tomography arteriography (MDCTA). METHODS: Thirty-five consecutive bronchial artery embolization sessions with preprocedural MDCTA were performed for 32 patients and 35 sessions. The MDCTA studies with computed tomography value of pulmonary trunk visually lower than that of ascending aorta were defined as "diagnostic MDCTA." Angiographic studies and "diagnostic MDCTA" were evaluated, respectively, for shunting into pulmonary artery. Based on the results of angiographic studies, diagnostic performance of "diagnostic MDCTA" was evaluated. RESULTS: The rate of diagnostic MDCTA was 63% (23 of 35). On "diagnostic MDCTA," sensitivity, specificity, and positive and negative predictive values for detecting shunts were 83% 100%, 100%, 94%, respectively. CONCLUSIONS: Systemic arterial pulmonary circulation shunts were detected on "diagnostic MDCTA" with high sensitivity and specificity.

Focal therapy with high-intensity focused ultrasound for the localized prostate cancer for Asian based on the localization with MRI-TRUS fusion image-guided transperineal biopsy and 12-cores transperineal systematic biopsy: prospective analysis of oncological and functional outcomes.

BACKGROUND: We evaluated clinical outcomes of region target focal therapy with high-intensity focused ultrasound (HIFU) for the localized prostate cancer (PCa) based on magnetic resonance imaging-based biopsy and systematic prostate biopsy for Asian. METHODS: We prospectively recruited patients with localized PCa, located their significant tumors using MRI-transrectal ultrasound (TRUS) elastic fusion image-guided transperineal prostate biopsy and 12-cores transperineal systematic biopsy, and focally treated these regions in which the tumors were located in the prostate using HIFU. Patients' functional and oncological outcomes were analyzed prospectively. RESULTS: We treated 90 men (median age 70 years; median PSA level 7.26 ng/ml). Catheterization was performed within 24 h after the treatment in all patients. Biochemical disease-free rate was 92.2% during 21 months follow-up when use of Phoenix ASTRO definition. In follow-up biopsy, significant cancer was detected in 8.9% of the patients in un-treated areas. Urinary functions, including international prostate symptom score (IPSS) (P < 0.0001), IPSS quality of life (QOL) (P = 0.001), overactive bladder symptom score (OABSS) (P < 0.0001), EPIC urinary domain (P < 0.0001), maximum urinary flow rate (P < 0.0001), and IIEF-5 (P = 0.001), had significantly deteriorated at 1 month after treatment, but improved to preoperative levels at 3 or 6 months. Rates of erectile dysfunction and ejaculation who had the functions were 86% and 70%, respectively, at 12 months after treatment. CONCLUSIONS: The present treatment for Asian would have similar oncological and functional outcomes to those in previous reports. Further large studies are required to verify oncological and functional outcomes from this treatment for patients with localized PCa.

Pulmonary perfusion by chest digital dynamic radiography: Comparison between breath-holding and deep-breathing acquisition.

PURPOSE: Pulmonary perfusion is an important factor for gas exchange. Chest digital dynamic radiography (DDR) by the deep-breathing protocol can evaluate pulmonary perfusion in healthy subjects. However, respiratory artifacts may affect DDR in patients with respiratory diseases. We examined the feasibility of a breath-holding protocol and compared it with the deep-breathing protocol to reduce respiratory artifacts. MATERIALS AND METHODS: A total of 42 consecutive patients with respiratory diseases (32 males; age, 68.6 ± 12.3 yr), including 21 patients with chronic obstructive pulmonary disease, underwent chest DDR through the breath-holding protocol and the deep-breathing protocol. Imaging success rate and exposure to radiation were compared. The correlation rate of temporal changes in each pixel value between the lung fields and left cardiac ventricles was analyzed. RESULTS: Imaging success rate was higher with the breath-holding protocol vs the deep-breathing protocol (97% vs 69%, respectively; P < 0.0001). The entrance surface dose was lower with the breath-holding protocol (1.09 ± 0.20 vs 1.81 ± 0.08 mGy, respectively; P < 0.0001). The correlation rate was higher with the breath-holding protocol (right lung field, 41.7 ± 9.3%; left lung field, 44.2 ± 8.9% vs right lung field, 33.4 ± 6.6%; left lung field, 36.0 ± 7.1%, respectively; both lung fields, P < 0.0001). In the lower lung fields, the correlation rate was markedly different (right, 15.3% difference; left, 14.1% difference; both lung fields, P < 0.0001). CONCLUSION: The breath-holding protocol resulted in high imaging success rate among patients with respiratory diseases, yielding vivid images of pulmonary perfusion.

Microballoon-related interventions in various endovascular treatments of body trunk lesions.

Occlusion balloon catheters of 5.2- or 6-French have been used for a few decades in various endovascular treatments of body trunk vascular lesions. However, these catheters may be difficult to place in cases of excessive vessel tortuosity, small vessels, and anatomic complexity. Recently, the introduction of the double lumen microballoon catheters for body trunk vascular lesions has allowed operators to advance them into more distal, smaller, and more tortuous vessels. Since the launch of the first generation microballoon catheters onto the market in Japan in 2011, the microballoon catheters have evolved and are now generally available for clinical use. The purpose of this article is to review the evolution and current clinical applications of the microballoon catheters in the field of interventional radiology.

Accuracy of real-time magnetic resonance imaging-transrectal ultrasound fusion image-guided transperineal target biopsy with needle tracking with a mechanical position-encoded stepper in detecting significant prostate cancer in biopsy-naïve men.

OBJECTIVE: To evaluate the accuracy of real-time elastic fusion image-guided transperineal prostate biopsy with needle tracking involving a mechanical position-encoded stepper in detecting clinically significant prostate cancer for biopsy-naïve men. METHODS: We prospectively recruited patients with serum prostate-specific antigen levels of 4.0-20 ng/mL and suspicious of prostate cancer on multiparametric magnetic resonance imaging. They underwent targeted biopsies for cancer-suspicious lesions and 12-core systematic biopsies. Pathological findings from biopsy cores and whole-mount specimens (for those who underwent radical prostatectomy) were analyzed. RESULTS: A total of 250 patients were included, in whom targeted and systematic biopsies detected significant cancers in 55% and 25%, respectively (P < 0.001). The targeted biopsy cores (n = 527) showed significantly greater biopsy-proven significant cancer detection rates (P < 0.001), cancer core length (P < 0.0001), cancer core percentage (P < 0.001) and Gleason scores (P < 0.001) than did the systematic biopsies. The significant cancer detection rate for targeted lesions (those with Prostate Imaging and Reporting and Data System classification scores of 5) was 80%. Biopsy-proven significant cancer detection rates for targeted lesions ≤10 mm and >10 mm were similar for Prostate Imaging and Reporting and Data System scores of 4 (P = 0.707) and 5 (P = 0.386). In whole-mount specimens (n = 30), locations for 95% of significant cancers were diagnosed preoperatively. Targeted biopsies alone diagnosed 79% of significant cancers. CONCLUSIONS: Although targeted biopsies are superior to systematic biopsies in detecting significant cancers, systematic biopsies maintain an important role in the diagnosis of prostate cancer in biopsy-naïve men.

Balloon-occluded retrograde transvenous obliteration using a new microballoon for gastric varices.

We here present a case involving a complicated type of gastric fundal varices treated by balloon-occluded retrograde transvenous obliteration. A newly developed 1.8-Fr tip coaxial microballoon catheter was successfully advanced into narrow and tortuous varices, and a sclerosant could be infused in a reasonable manner, avoiding reflux into collaterals. Divided injections of sclerosant were performed over two days, via a microballoon catheter that remained inserted overnight with balloon inflation, and the sclerosant could be infused sufficiently in the entirety of the varices. The varices were completely thrombosed and prominently reduced.

Perirenal lymphatic systems: Evaluation using spectral presaturation with inversion recovery T2 -weighted MR images with 3D volume isotropic turbo spin-echo acquisition at 3.0T.

PURPOSE: To evaluate the normal anatomy of the perirenal lymphatics using spectral presaturation with inversion recovery (SPIR) T2 -weighted magnetic resonance imaging (MRI) with 3D volume isotropic turbo spin-echo acquisition (VISTA) at 3.0T. MATERIALS AND METHODS: This retrospective study was approved by the two Institutional Review Boards and informed consent was waived. Thin-collimated axial images obtained using SPIR T2 -weighted MR imaging sequences with 3D VISTA at 3.0T from 50 patients (100 kidneys) with normal renal function were retrospectively reviewed. The perirenal lymphatic vessels were defined as fluid signal intensity structures on this MRI sequence. Two readers independently assessed the degree of visualization of the perirenal lymphatics using a 4-point scale in four anatomical regions, including the renal hilar, capsular, communicating pericapsular, and subfascial lymphatics, and interobserver agreement was evaluated with weighted kappa statics. The detectability of each lymphatic system was calculated for each reader using confidence level ratings of grades 1 and 2 as positive and grades 3 and 4 as negative. RESULTS: Interobserver agreement for the visualization grades was almost perfect (kappa value = 0.9). The renal hilar lymphatics along the renal vein were clearly identified in all patients. The detectability of other perirenal lymphatics was 44% for the capsular lymphatics, 39% for communicating pericapsular lymphatics, and 22% for the subfascial lymphatics. There was no laterality regarding the detectability of the perirenal lymphatics. CONCLUSION: The findings of this study support the feasibility of SPIR T2 -weighted MR images with 3D-VISTA at 3.0T for evaluating the perirenal lymphatic systems. J. MAGN. RESON. IMAGING 2016;44:897-905.

Balloon-occluded arterial stump pressure before balloon-occluded transarterial chemoembolization.

OBJECTIVE: To evaluate balloon-occluded arterial stump pressure (BOASP), which is responsible for effective balloon-occluded transarterial chemoembolization (B-TACE), at each hepatic arterial level before B-TACE using a 1.8-French tip microballoon catheter for unresectable hepatocellular carcinoma (HCC). MATERIAL AND METHODS: The BOASP at various embolization portions was retrospectively investigated. "Selective" and "non-targeted" BOASP was defined as the BOASP at the subsegmental or segmental artery and the lobar artery, respectively. RESULTS: The measurement of the BOASP was carried out in 87 arteries in 47 patients. BOASP > 64 mmHg was revealed in the caudate lobe artery (A1) and the left medial segmental (A4), right anterior superior segmental (A8), anterior segmental, right and left hepatic arteries. Significant difference was noted in the incidence of BOASP above 64 mmHg between "non-targeted" and "selective" BOASP (p = 0.01). "Non-targeted" BOASP was significantly greater than "selective" BOASP (p = 0.0147). In addition, the BOASP in A1, 4, 8 and the anterior segmental arteries were significantly greater than in the other subsegmental and segmental arteries (p = 0.0007). CONCLUSION: "Non-targeted" B-TACE should be avoided to perform effective B-TACE and "selective" B-TACE at A1, 4, 8 and the anterior segmental arteries may become less effective than at the other segmental or subsegmental arteries.

Platelets: Small in Size But Essential in the Regulation of Vascular Homeostasis - Translation From Basic Science to Clinical Medicine.

Platelets are small blood cells that adhere to the site of vessel injury where von Willebrand factor (VWF) is expressed. Platelets bind to VWF through interaction with a membrane protein, glycoprotein (GP) Ibα. Next, the accumulated platelets are activated to change their morphological and biochemical characteristics. Various vasoactive substances, such as immune-regulatory CD40 ligand, are released locally from activated platelet cells to maintain homeostasis of the vascular system. Major roles played by platelets in the regulation of hemostasis and thrombus formation include local activation of the coagulation cascade. Translocation of negatively charged phospholipids to the surface of activated platelets helps in the formation of prothrombinase complex, which efficiently produces thrombin. Thrombin produces fibrin around the activated platelets and further activates the platelets through thrombin receptor stimulation. Of the various platelet-stimulating receptors and activation signals, cyclo-oxygenase-1, P2Y12 adenosine 5'-diphosphate receptor, and thrombin receptor (protease activated receptor)-1 blockers are used clinically as antiplatelet agents. In the future, precise understanding of the quantitative contribution of platelet function in hemostasis and pathological thrombus formation should lead to the development of effective antithrombotic agents without increasing the risk of serious bleeding complications.