Organized Hematoma Research Articles

A case of chronic contained rupture of abdominal aortic aneurysm mimicking a retroperitoneal tumor.

Chronic contained rupture of abdominal aortic aneurysm (CCR-AAA) is a rare subtype of abdominal aortic rupturethat can mimic other retroperitoneal lesions. We report a case of CCR-AAA in a man in his sixties who presented witha 10-month history of right low back pain and weight loss. Contrast-enhanced computed tomography (CT) revealed alobulated retroperitoneal mass around the abdominal aorta, initially misdiagnosed as a possible hemorrhagicretroperitoneal tumor. Despite multiple imaging studies including CT, magnetic resonance imaging (MRI), and 18F-fluorodeoxyglucosepositron emission tomography (FDG-PET)/CT, as well as a CT-guided biopsy, the correct diagnosisremained elusive for 34 months. Key findings included subtle aortic wall irregularity on CT, high signal intensity onT1-weighted MRI suggesting hematoma, peripheral FDG uptake on PET/CT, and histological findings of biopsy tissueconsistent with organizing hematoma. Surgery confirmed the diagnosis, revealing an organized hematoma with adefect in the right wall of the abdominal aortic aneurysm. This case demonstrates that CCR-AAA can present withatypical radiological features, potentially leading to misdiagnosis. When encountering a para-aortic mass with ahemorrhagic component, careful observation of the AAA morphology and aortic wall contour is crucial for anaccurate diagnosis of CCR-AAA.

Sinonasal Organizing Hematoma: Demographics, Diagnosis, and Treatment Outcomes of 112 patients.

Sinonasal organizing hematoma (OH) is a rare, nonneoplastic lesion that often presents with epistaxis, a reddish mass, and destruction of the involved sinonasal structures. Due to its rarity, the demographics, diagnostic modalities, treatment strategies, and outcomes have not yet been studied in a large, long-term study. Retrospect cohort of 112 sinonasal OH patients treated between 1997 and 2020 in a tertiary, university hospital were evaluated. Demographics, systemic comorbidities, sinonasal surgery history, serum laboratory tests, radiological findings, and treatment results were collected. The present study aimed to assess the accuracy of preoperative computed tomography (CT), Gadolinum-enhanced magnetic resonance (MR), and punch biopsies in detecting sinonasal OH as the most likely diagnosis. In addition, incidental differences by age and year of diagnosis were calculated using the Poisson log-linear regression model. The median age was 44, and 58% were male. Fewer than 20% of these cases had a chronic systemic comorbidity, bleeding tendency, or sinonasal surgery history. MR had the highest accuracy of (87%) to detect sinonasal OH as the most likely diagnosis, compared with contrast-enhanced-CT (53%), punch biopsy (49%), and non-enhanced-CT (16%) (all <0.05). Sinonasal OH incidence did not vary by age, but the yearly rate significantly increased by 1.05 times over 23 years (p < 0.05). Notably, 84% of 112 patients received surgical removal through the assistance of an endoscope, and none had substantial bleeding without preoperative embolization. Sinonasal OH was observed regardless of age, sex, systemic comorbidities, bleeding tendency, prior sinonasal surgery, or trauma. Preoperative MR gives the highest accuracy for detecting this disease. Sinonasal OH may be safely managed with endoscopic-assisted surgery removal without embolization. 4 Laryngoscope, 134:1581-1590, 2024.

Nasoalveolar Rhabdomyosarcoma Presenting as Traumatic Nasal Injury: A Rare Case Report Mimicking Organized Hematoma

The nasoalveolar region is an uncommon area of all rhabdomyosarcoma (RMS) cases. RMS has a bimodal distribution in children, occurring in those aged two to four years and 12 to 16 years. The authors presented an unusual case of alveolar RMS that presented at a young age, in an uncommon region, with an atypical presentation, and imaging findings mimicking organized hematoma and complicated nasoalveolar cyst. Confounding as a result of the presence of trauma can delay diagnosis and treatment. Keywords: Nasoalveolar; Rhabdomyosarcoma; Hematoma

Retiform endothelial hyperplasia mimicking cavernous malformation as a late complication of Gamma Knife radiosurgery.

Gamma Knife radiosurgery (GKRS) is a powerful tool for the management of arteriovenous malformations; however, newly formed mass lesions resembling cavernous malformations are a rare late complication of GKRS. In this retrospective study, the authors tried to clarify the unique histological features of these mass lesions. The authors retrospectively reviewed the clinical course of 889 patients who had undergone GKRS for arteriovenous malformations at their institute from 1991 to 2021. Among the 848 patients who had been followed up periodically with neuroradiological imaging, 37 developed a mass lesion mimicking a cavernous malformation and underwent surgical removal of the lesion. The median volume of the original nidus was 3.7 cm3 (range 0.07-30.5 cm3), and the median prescription dose was 21 Gy (range 12-25 Gy). The histological characteristics and radiological and clinical features of the 37 patients were investigated. Histological examination showed an organized hematoma and a structure termed "retiform endothelial hyperplasia" (RFEH) consisting of endothelium forming multiple lumen-like vascular channels mimicking cavernous malformations but lacking the subendothelial connective tissue that forms the typical vascular wall structure found in cavernous angioma and capillary telangiectasia. RFEH was detected a median of 10.8 years (range 3.2-27.4 years) after GKRS. Neuroimaging showed hematoma surrounded by massive brain edema in all 37 patients. Symptoms caused by mass effect of the lesion and perifocal edema worsened relatively rapidly but completely disappeared after surgery. No recurrence or morbidity occurred after the surgery. The delayed formation of RFEH that is mimicking a cavernous malformation neuroradiologically but is histologically distinct from a vascular malformation is a potential complication of GKRS. Its progressive clinical course suggests that surgical removal should be considered for symptomatic patients and/or patients with an apparent radiological mass sign.

P415 THE STRANGE CASE OF A LATE POCKET HEMATOMA

Abstract Case report: male, 85 years old. Hospitalization in 2013 at the Ancona Cardiology Department due to severe left ventricular dysfunction. In the history of pulmonary lobectomy results (2005). ⦁ EKG: PR 220 msec, left bundle block ⦁ coronary angiography: ed ⦁ blood analysis: hemoglobin 15 g/dl, PLT 229/mm3, Creatinine 1.1 mg/dl, Glycemia 84 mg/dl. ⦁ Echocardiogram: severe LV dilatation (LVVT 105 ml/m2) and severe reduction of LVEF due to diffuse hypokinesia. Strain test for possible CRTD implant: no intraventricular asynchrony. A single–chamber ICD was implanted in primary prevention in the left subclavicular site ( antibiotic prophylaxis with ciprofloxacin 1 g). Chest x–ray showed correct lead placement, no pneumothorax. The patient was discharged with antibiotic therapy. Since then he has continued the cardiological follow–up on a regular basis (cardiological visit + six–monthly ICD check). It should be noted that NOAC (Rivaroxaban 20 mg) was introduced in 2020 for the detection of atrial fibrillation. In December 2021, at last ICD check: no arrhythmic events, no alterations of the electrical parameters, good condition of the PM pocket. On 09.01.22, access to the ER due to the appearance of elastic swelling of the pocket. Apiretic. The ER doctor performed ultrasound (non–trabecular subcutaneous effusion) and proceeded to aspirate 15 cc of serum–blood fluid. He discharged the patient with appointment at the PM clinics. Cardiological consultation or blood chemistry tests were not carried out. On 19.01.22 the patient presented to our clinics: voluminous elastic swelling of the soft tissues overlying the pocket, which appeared floating. No local inflammation or cutaneous ischemic suffering. No solutions of continuity in the skin. No pain. He also reported not having taken the prescribed antibiotic. He denied fever or trauma in the previous weeks. As the blood chemistry tests were not performed in the ER, the blood count (Hb? WBC?), renal function (rivaroxaban overdose?), inflammation indices were not known (CRP? PCT?), coagulation function (spontaneous INR?). Urgent hospitalization was scheduled for surgical revision, pocket decompression, swab culture and blood cultures. Conclusions The hypotheses are hematoma during NOAC, pocket infection or cystic hygroma. After surgery evidence of organized hematoma of tissue adjacent to the pocket with negative blood cultures.

Right Heart Failure as an Atypical Presentation of Chronic Type a Aortic Dissection - Multimodality Imaging for Accurate Diagnosis and Treatment. A Case Report and Mini-review of Literature.

BackgroundAn intrapericardial organized haematoma secondary to chronic type A aortic dissection is an extremely rare cause of right heart failure. Imaging studies are essential in recognising and diagnosis of this distinctive medical condition and guiding the anticipated treatment.Case presentationA 70-year-old male patient was admitted for progressive symptoms of right heart failure. His cardiovascular history exposed an aortic valve replacement 22 years before with a Medtronic Hall 23 tilting valve with no regular follow-up. Classical signs of congestion were recognized at physical examination. Transthoracic two-dimensional echocardiography and thoraco-abdominal computed tomography angiography, as essential parts of multimodality imaging algorithm, established the underlying cause of right heart failure. Under total cardiopulmonary bypass and cardiac arrest, surgical removal of the haematoma and proximal repair of the ascending aorta with a patient-matched vascular graft were successfully performed. The patient was discharged in good condition with appropriate pharmacological treatment, guideline-directed; no imagistic signs of acute post-surgery complications were ascertained.ConclusionThis paper highlights the importance of recognizing and providing a timely clinical and imagistic diagnosis of this very rare, potentially avoidable cause of right heart failure in patients with previous cardiac surgery.

Organized Hematoma after Intra-Arterial Chemoradiotherapy for Maxillary Sinus Cancer: A Case Report.

An organized hematoma (OH) is a relatively rare benign lesion of the paranasal sinuses. Traditionally, it has been reported to occur following trauma, surgery, and sinus hemorrhagic lesions and in various bleeding predispositions. OHs are sometimes difficult to differentiate from malignancy because of the similar clinical symptoms and bone destruction. It is especially difficult when OHs occur in the same location as the primary tumor after treatment of a malignant tumor. In this paper, we report two cases of OH that occurred after intra-arterial chemoradiotherapy (IACRT) for maxillary sinus cancer. In one case, FDG accumulation was found in PET/CT and suspected to be a cancer recurrence. However, the postoperative pathology showed no malignant findings. This suggests that OH may show accumulation on 18 F-fluorodeoxyglucose positron emission tomography (FDG-PET). In both cases, bleeding from the maxillary sinus continued after surgery. In one case, recurrence was observed, and in the other, nasal irrigation prevented the pooling of blood in the maxillary sinus, and no recurrence was observed. These cases suggest that OH after IACRT may easily recur because the bleeding continues even after surgery. In such cases, nasal irrigation or preoperative embolization may be helpful to avoid recurrence.

Sino Nasal Organizing Hematoma Masquerading as Sino-Nasal Neoplasm.

Sino-nasal organized hematoma (OH) is an uncommon, benign condition of the sinuses. It mimics neoplasm in its clinical presentation as well on imaging appearance. Careful evaluation of the clinical history and imaging features is essential to avoid misdiagnosis. We present an interesting case of sino-nasal organizing hematoma in a 26-year-old male patient, masquerading as sino-nasal neoplasm.

Preoperative Arterial Embolization to Avoid Intraoperative Bleeding during Endoscopic Sinus Surgery for Organized Hematoma of the Maxillary Sinus: A Case Series and Literature Review

Purpose: This study aimed to evaluate the safety and efficacy of preoperative arterial embolization of organized hematoma of the maxillary sinus. Material and Methods: Seven patients who were pathologically diagnosed with an organized hematoma of the maxillary sinus and who underwent endoscopic sinus surgery following preoperative arterial embolization for the same from July 2013 to April 2020 at our hospital were included. A literature review of the PubMed database was performed to identify 13 cases on organized hematomas of the maxillary sinuses. The embolization and nonembolization groups comprised patients who underwent preoperative embolization (n = 10, seven from this study and three from literature) and those who did not undergo preoperative embolization (n = 10, from literature), respectively. Outcomes of embolization including embolization-related complications and postoperative bleeding were assessed, and volumes of intraoperative blood loss and duration of surgery were compared between the groups. Results: No preoperative embolization-related complications were observed in our cases. The volume of surgical blood loss in the seven cases varied from 0 to 100 mL with a median of 30 mL, and the duration of surgery ranged from 45 to 166 minutes with a median of 112 minutes. The volume of blood loss was significantly lower for the embolization group than that for the nonembolization group (p = 0.0031). There was no statistically significant difference regarding duration of surgery between the groups (p > 0.10). Conclusions: Preoperative embolization of an organized hematoma of the maxillary sinus is a safe and effective method that helps prevent serious intraoperative hemorrhage.

Transcondylar Approach for Resection of Medullary Cavernous Malformation: 2-Dimensional Operative Video.

Cavernous malformations located within the brainstem present with a high rate of neurological symptoms and carry a more aggressive course in both pediatric and adult populations.1,2 Cavernomas within the medulla are the rarest form, representing only 5% of all brainstem lesions.3 Repeated hemorrhage of brainstem cavernomas is associated with significant and cumulative neurological deficits and thus requires treatment.4 Microsurgical resection has become the optimal mode of treatment with the aim of resecting the live malformation and not merely the multiaged, organized hematoma.4 This is best achieved by approaching the cavernoma at the location where it projects to the surface and entering the lesion through a safe brainstem anatomic zone. For ventrally located lesions in the medulla, a transcondylar skull base approach provides a direct trajectory to the entry zone through a short surgical distance without the need to manipulate or retract neurovascular structures.5-8 Neuronavigation and intraoperative neurophysiological monitoring of somatosensory evoked potential, motor, and lower cranial nerves are adjuncts to increase patient safety. Radiosurgery for the treatment of brainstem cavernous malformations has been proposed; however, it demonstrates high risk and variable and often poor response rates.9 We present a surgical video demonstrating the transcondylar approach and resection of a medullary cavernoma in a 54-yr-old woman who has had multiple known prior hemorrhages and presented with a new onset of facial numbness and weakness, ataxia, and left body sensory loss. The patient consented to surgery and to photograph publication. Images at 1:28, 1:43 (left), 2:02 from Al-Mefty O, Operative Atlas of Meningiomas, © LWW, 1997,5 with permission. Images at 1:43 (right) from Arnautovic et al,8 with permission from JNSPG.

Celiac Artery Compression After a Spine Fracture, and Pericardium Rupture After Blunt Trauma: A Case Report from a Single Injury

Celiac artery compression is a rare condition in which the celiac artery is compressed by the median arcuate ligament. Case reports of compression after trauma are hard to find. Blunt traumatic pericardium rupture is also a rare condition. We report a single patient who experienced both rare conditions from a single blunt injury. An 18-year-old woman was brought to the trauma center after a fatal motorcycle accident, in which she was a passenger. The driver was found dead. Her vital signs were stable, but she complained of mild abdominal pain, chest wall pain, and severe back pain. There were no definite neurologic deficits. Her initial computed tomography (CT) scan revealed multiple rib fractures, moderate lung contusions with hemothorax, moderate liver injury, and severe lumbar spine fracture and dislocation. She was brought to the angiography room to check for active bleeding in the liver, which was not apparent. However, the guide wire was not able to pass through the celiac trunk. A review of the initial CT revealed kinking of the celiac trunk, which was assumed to be due to altered anatomy of the median arcuate ligament caused by spine fractures. Immediate fixation of the vertebrae was performed. During recovery, her hemothorax remained loculated. Suspecting empyema, thoracotomy was performed at 3 weeks after admission, revealing organized hematoma without pus formation, as well as rupture of the pericardium, which was immediately sutured, and decortication was carried out. Five weeks after admission, she had recovered without complications and was discharged home. Keywords: Celiac artery; Pericardium; Rupture; Blunt injury

Spinal Subdural Hematoma With Paraplegia Mimicking Dorsolumbar Prolapsed Disc: A Case Report

Background and Importance: Spinal Subdural Hematoma (SSH) is a rare condition with an unknown incidence in the general population. Iatrogenic spinal subdural hematoma radiologically mimicking a prolapsed dorsolumbar disc has not been published in the literature. Case Presentation: A 65-year-old female presented with altered sensorium and generalized weakness for 3 days evaluated by a neurologist who diagnosed it as a metabolic encephalopathy with Syndrome of Inappropriate Antidiuretic Hormone secretion (SIADH) with severe anemia and hypothyroidism. She underwent a diagnostic lumbar puncture and following which, within 24 hours, she developed weakness of both the lower limbs. MRI of dorsolumbar spine was done which revealed D12-L1 extruded disc causing severe compression to the conus medullaris with D12-L2 subarachnoid lesion and cord edema. On opening the dura, a large organized hematoma on the anterior aspect of the conus was seen and evacuated. Conclusion: Spinal subdural hematoma presents with a spectrum of signs and symptoms. Although MRI is the investigation of choice but SSH presenting like a prolapsed intervertebral disc on MRI is one of its kinds and should be kept in mind since it carries a grave prognosis if not treated early with emergency decompression.

Giant Encapsulated Anterior Abdominal Wall Haematoma Complicating Mesh Incisional Hernia Repair: Challenges of Management in a High-Risk Term Pregnancy in a Low Resource Setting

Giant encapsulated haematoma of the anterior abdominal wall is an unusual complication of mesh incisional hernia repair. The commonest symptoms are swelling and pain. It can be diagnosed with ultrasonography and Computed Tomography (CT) scan. The objective of this case report is to illustrate the challenges of management of a complex pathology in a high-risk term pregnancy. In this case report, a 28-year-old morbidly obese multiparous woman with two previous ventral wall hernia repairs and two previous caesarian sections, presented at term to the prenatal clinic with protruding anterior abdominal mass. Initial preoperative diagnosis aided by ultrasonography was a herniated term gestation through an incisional hernia. Intraoperatively, the surgical team was faced with the challenge of managing a longstanding giant organized haematoma of the anterior abdominal wall and the anticipation and prevention of obstetric complications associated with two previous caesarian sections and a big baby. This report illustrates that good clinical assessment combined with sonographic assessment of complex cases by an experienced radiologist is crucial to avoid missed diagnosis. A multidisciplinary team management was essential for a successful outcome.

Partial Orchiectomy

Aim of the Study: The aim of this study is to review our collective experience with partial orchectomy due to testicular tumors in a secondary hospital of Greece. Materials and Methods: In total four young patients with relative indications for a partial orchectomy (single testis and/or tumors &lt;2 cm in diameter, patient consent for a close follow-up, negative tumor markers) underwent partial orchiectomy in our institution. All operations were performed under clamping of the spermatic cord, and postoperative period was uneventful. Results: Pathology examination revealed one case of Sertoli cell only tumor, one patient with testicular cancer of mixed pathology (embryonal and teratoma), one case of organized hematoma, and one case with focal atypical inflammation. Patients underwent a close follow-up protocol. The patient with the mixed tumor was subjected to adjuvant chemotherapy with BEP (bleomycin, etoposide, cisplatin). The patient with atypical inflammation had a single testis due to a history of contralateral seminoma. During follow-up, he developed local tumor recurrence and underwent orchiectomy that revealed the presence of seminoma. The patient was set under testosterone replacement therapy. Conclusions: Partial orchiectomy represents a safe treatment option in the management of small testicular tumors. A benign pathology in up to 50% of cases should be expected. In case of both malignant and benign pathologies, a close follow-up is deemed necessary for the timely recognition of local recurrences in case of insufficient cancer eradication.

Rare diseases of the maxillary sinus

Silent sinus syndrome (SSS), organized hematoma (OH), and pneumosinus dilatans (PD) are rare, usually unilateral diseases of the maxillary sinus. Due to misinterpretation, excessive diagnostics and unnecessarily aggressive surgery or adelay in diagnostics and treatment are common. The objective of this study was to develop reasonable and comprehensible diagnostic criteria to improve diagnosis and treatment of these rare diseases. In this retrospective study, all patients treated for SSS, OH, and PD from 2012 to 2019 were identified. Patient history, diagnostic tests and results, and postoperative course were analyzed and compared with the available literature. During the study period, 7patients with SSS, 3patients with PD, and 2patients with OH were treated and available for follow-up. Comparison of these patients with the literature allowed us to develop diagnostic criteria. Medical history combined with endoscopic and radiologic criteria should improve preoperative diagnosis of these three rare diseases of the maxillary sinus and help to distinguish them from other differential diagnoses. This approach should minimize morbidity for the patients.

MR and CT imaging features of sino-nasal organized hematomas.

To describe the MR and CT imaging features of organized hematomas [OH]. A retrospective analysis of MR imaging and CT of eight patients [6 male, 2 females; age range is 6-86years] with pathological proven OH was performed. Routine contrast MR and CT scan were done for all patients, and diffusion-weighted imaging and dynamic contrast CT were done for only five patients. Imaging analysis was done for the signal intensity, the enhancement pattern at MR imaging, the ADC value at DWI, bone remodeling at CT, and the neo-vascularization at dynamic contrast CT. OH revealed T2 hypo-intense of the matrix in all patients with complete [n = 3] and incomplete [n = 5] marginal hypo-intensity rim. The lesions revealed a frond-like pattern of contrast enhancement of the central part of the lesion that associated with a peripheral rim of contrast enhancement. OH revealed unrestricted diffusion with high ADC value [1.7-2.5 × 10-3cm2/s] in 5 patients. CT scan showed geographic bone remodeling and thinning of the nasal turbinates, and the sinus wall and contrast CT showed neo-vascularization with frond-like branching arteries of the central part of the lesions in five patients. We conclude that MR and CT imaging findings can help in the diagnosis of OH.

Effect of Stiffness of Large Extravascular Hematomas on Their Susceptibility to Boiling Histotripsy Liquefaction in Vitro

Large intra-abdominal, retroperitoneal and intramuscular hematomas are common consequences of sharp and blunt trauma and post-surgical bleeds, and often threaten organ failure, compartment syndrome or spontaneous infection. Current therapy options include surgical evacuation and placement of indwelling drains that are not effective because of the viscosity of the organized hematoma. We have previously reported the feasibility of using boiling histotripsy (BH)—a pulsed high-intensity focused ultrasound method—for liquefaction of large volumes of freshly coagulated blood and subsequent fine-needle aspiration. The goal of this work was to evaluate the changes in stiffness of large coagulated blood volumes with aging and retraction in vitro, and to correlate these changes with the size of the BH void and, therefore, the susceptibility of the material to BH liquefaction. Large-volume (55–200 mL) whole-blood clots were fabricated in plastic molds from human and bovine blood, either by natural clotting or by recalcification of anticoagulated blood, with or without addition of thrombin. Retraction of the clots was achieved by incubation for 3 h, 3 d or 8 d. The shear modulus of the samples was measured with a custom-built indentometer and shear wave elasticity (SWE) imaging. Sizes of single liquefied lesions produced with a 1.5-MHz high-intensity focused ultrasound transducer within a 30-s standard BH exposure served as the metric for susceptibility of clot material to this treatment. Neither the shear moduli of naturally clotted human samples (0.52 ± 0.08 kPa), nor their degree of retraction (ratio of expelled fluid to original volume 50%–58%) depended on the length of incubation within 0–8 d, and were significantly lower than those of bovine samples (2.85 ± 0.17 kPa, retraction 5%–38%). In clots made from anticoagulated bovine blood, the variation of calcium chloride concentration within 5–40 mmol/L did not change the stiffness, whereas lower concentrations and the addition of thrombin resulted in significantly softer clots, similar to naturally clotted human samples. Within the achievable shear modulus range (0.4–1.6 kPa), the width of the BH-liquefied lesion was more affected by the changes in stiffness than the length of the lesion. In all cases, however, the lesions were larger compared with any soft tissue liquefied with the same BH parameters, indicating higher susceptibility of hematomas to BH damage. These results suggest that clotted bovine blood with added thrombin is an acceptable in vitro model of both acute and chronic human hematomas for assessing the efficiency of BH liquefaction strategies.

Primary trans-calvarial lymphoma: A rare entity

Primary trans-calvarial lymphoma with both intracranial and extracranial extension is a scarcely described entity in published literature. Most often, these lesions are misdiagnosed as hematomas or meningiomas. We hereby report an interesting case of a 60-year-old female presenting with a large scalp mass. The diagnosis at the time of referral was an organized scalp hematoma. Magnetic resonance imaging of the brain revealed a large isointense enhancing mass lesion with transcalvarial extension involving the scalp as well as the meninges. Histopathology and immunohistochemistry confirmed a diagnosis of diffuse large B-cell lymphoma. Our case was unique in that the presentation was with a large scalp lesion with a reasonable meningeal component and invasion of the superior sagittal sinus without any associated focal neurological deficit.

A Case of Maxillary Organized Hematoma Growing Rapidly Caused by Myelodysplastic Syndrome

A Case of Maxillary Organized Hematoma Growing Rapidly Caused by Myelodysplastic Syndrome

Novel Aptamer-Functionalized Nanoparticles Enhances Bone Defect Repair By Improving Stem Cell Recruitment.

BackgroundThe restoration and repair method in the clinic of delayed fracture healing and non-union after comminuted fractures are urgently needed to improve the prognosis of patients. The recruitment of endogenous stem cells has been considered a promising approach in bone defect repair.ProposeThe aim of this study was to generate a de novel MSCs aptamer and developed the first, feasible, economical, bio-compatible, and functional MSCs aptamer-directed nanoparticles without complex manufacture to recruit mesenchymal stem cells (MSCs) for bone defect regeneration.MethodsWhole-cell SELEX was used to generate a de novel MSCs aptamer. Flow cytometry was applied to assess the binding specificities, affinities and sorting abilities of the aptamers. Nano-Aptamer Ball (NAB) was constructed by NHS/EDC reaction. The diameter and zeta of NAB were assessed by dynamic light scattering. CCK8 assay was utilized to evaluate whether NAB could cause non-specific cytotoxicity and induce cell proliferation. To evaluate the bone repair capacity of NAB, histomorphological staining, alizarin red and micro X-ray were used to observe the repair degree of defect in vivo. ELISA was used to detect osteopontin (OPN), osteocalcin (BGP) by, and alkaline phosphatase (ALP) in peripheral blood.ResultsMSCs aptamer termed as HM69 could bind with MSCs with high specificity and Kd of 9.67 nM, while has minimal cross-reactivities to other negative cells. HM69 could capture MSCs with a purity of >89%. In vitro, NAB could bind and capture MSCs effectively, whereas did not cause obvious cytotoxicity. In vivo, serum OPN, BGP, and ALP levels in the NAB group of rats were increased at both 2 and 4 weeks, indicating the repair and osteogenesis generation. The healing of bone defects in the NAB group was significantly better than control groups, the defects became blurred, and local trabecular bone growth could be observed in X-ray. The organized hematoma and cell growth in the bone marrow of the NAB group were more vigorous in bone sections staining.ConclusionThese suggested that HM69 and HM69-functionalized nanoparticles NAB exhibited the ability to recruit MSCs both in vitro and in vivo and achieved a better outcome of bone defect repair in a rat model. The findings demonstrate a promising strategy of using aptamer-functionalized bio-nanoparticles for the restoration of bone defects via aptamer-introduced homing of MSCs.