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There are few studies utilizing only IR cameras for long-distance gender recognition, and they have shown low recognition performance due to their lack of color and texture information in IR images with a complex background. Therefore, a rough body segmentation-based gender recognition network (RBSG-Net) is proposed, with enhanced gender recognition performance achieved by emphasizing the silhouette of a person through a body segmentation network. Anthropometric loss for the segmentation network and an adaptive body attention module are also proposed, which effectively integrate the segmentation and classification networks. To enhance the analytic capabilities of the proposed framework, fractal dimension estimation was introduced into the system to gain insights into the complexity and irregularity of the body region, thereby predicting the accuracy of body segmentation. For experiments, near-infrared images from the Sun Yat-sen University multiple modality re-identification version 1 (SYSU-MM01) dataset and thermal images from the Dongguk body-based gender version 2 (DBGender-DB2) database were used. The equal error rates of gender recognition by the proposed model were 4.320% and 8.303% for these two databases, respectively, surpassing state-of-the-art methods.

Objective This study aimed to evaluate the treatment of spinal stenosis with spondylolisthesis using bilateral-contralateral unilateral biportal endoscopic (UBE) decompression to minimize facet joint damage. Methods We retrospectively evaluated 42 patients with grade 1 spondylolisthesis who underwent bilateral-contralateral UBE decompression between July 2018 and September 2019. To identify segmental instability, static and dynamic images from preoperative and postoperative procedures and final follow-up radiographs were reviewed. Lateral radiograph slippage ratio, sagittal motion, and facet joint preservation were evaluated. Clinical assessments were conducted using the visual analogue scale (VAS), Oswestry Disability Index (ODI), and modified MacNab criteria. Results The average final follow-up period was 26.5 ± 1.3 months. The average preoperative slip percentage was 15.70% ± 5.25%, which worsened to 18.80% ± 5.41% at the final follow-up (p < 0.005). The facet joint preservation rate was 95.6% ± 4.1% on the contralateral side. Improvements in the VAS scores (leg pain: from 7.9 ± 2.2 to 3.1 ± 0.7; p < 0.005; back pain: from 7.2 ± 3.0 to 2.8 ± 1.0; p < 0.005) were observed at the final follow-up. The mean preoperative ODI was 26.19 ± 3.42, which improved to 9.6 ± 1.0 (p < 0.005). Thirteen patients exhibited delayed focal segmental instability following decompression. Despite the absence of symptoms or improvement with conservative treatment in the majority of patients with delayed instability, two patients required fusion surgery to address the instability. Additionally, 2 patients developed facet synovial cysts, while 2 experienced spinous process fractures. Conclusion Bilateral decompression with a contralateral UBE approach could be an effective and alternative treatment method to reduce instability in spinal stenosis with grade 1 spondylolisthesis.

The accurate recognition of a brain tumor (BT) is crucial for accurate diagnosis, intervention planning, and the evaluation of post-intervention outcomes. Conventional methods of manually identifying and delineating BTs are inefficient, prone to error, and time-consuming. Subjective methods for BT recognition are biased because of the diffuse and irregular nature of BTs, along with varying enhancement patterns and the coexistence of different tumor components. Hence, the development of an automated diagnostic system for BTs is vital for mitigating subjective bias and achieving speedy and effective BT segmentation. Recently developed deep learning (DL)-based methods have replaced subjective methods; however, these DL-based methods still have a low performance, showing room for improvement, and are limited to heterogeneous dataset analysis. Herein, we propose a DL-based parallel features aggregation network (PFA-Net) for the robust segmentation of three different regions in a BT scan, and we perform a heterogeneous dataset analysis to validate its generality. The parallel features aggregation (PFA) module exploits the local radiomic contextual spatial features of BTs at low, intermediate, and high levels for different types of tumors and aggregates them in a parallel fashion. To enhance the diagnostic capabilities of the proposed segmentation framework, we introduced the fractal dimension estimation into our system, seamlessly combined as an end-to-end task to gain insights into the complexity and irregularity of structures, thereby characterizing the intricate morphology of BTs. The proposed PFA-Net achieves the Dice scores (DSs) of 87.54%, 93.42%, and 91.02%, for the enhancing tumor region, whole tumor region, and tumor core region, respectively, with the multimodal brain tumor segmentation (BraTS)-2020 open database, surpassing the performance of existing state-of-the-art methods. Additionally, PFA-Net is validated with another open database of brain tumor progression and achieves a DS of 64.58% for heterogeneous dataset analysis, surpassing the performance of existing state-of-the-art methods.

Objective Advanced biportal endoscopic surgery techniques can be used to treat thoracic myelopathy secondary to ossification of the ligamentum flavum (OLF). This case series elaborates on a feasible biportal endoscopic technique for thoracic OLF removal and evaluates clinical and radiological outcomes. Methods A biportal endoscopic posterior thoracic laminectomy was performed to remove the thoracic OLF. Surgical techniques have evolved from inside-out piecemeal removal methods to outside-in en bloc removal methods. Preoperative computed tomography was performed to analyze dural ossification and OLF types. Intraoperative videos were reviewed to observe dural ossification and to determine the surgical method. Neurological outcomes were assessed using the Japanese Orthopaedic Association (JOA) score. Results Clinical symptoms and neurological function improved markedly after surgery (JOA score, preoperative: 12.6 ± 1.0, final follow-up: 15.6 ± 1.2). The mean operation time per segment was not short (106.6 ± 38 minutes). At early experience stages, inside-out piecemeal decompression was used and it caused intraoperative spinal cord injury. However, outside-in en bloc decompression technique did not induce neural complications. Postoperative segmental instability and correlated mechanical back pain were not observed. Conclusion The biportal endoscopic posterior thoracic approach is an attractive surgical option to treat thoracic spondylotic myelopathy secondary to OLF. Piecemeal inside-out decompression can induce irreversible spinal cord injury, especially in the early experience stages. Outside-in decompression is more efficient and safer than inside-out pattern procedures by minimizing dural manipulation. Nonetheless, this technique is technically demanding and should only be performed in selected patients after acquiring abundant experience with endoscopic spine surgeries.

After endoscopic lumbar foraminotomy, decreased disc height commonly causes foraminal restenosis and accompanying lateral recess stenosis. Interlaminar contralateral endoscopic lumbar foraminotomy can be used to treat multiple recurrent lesions instead of fusion surgery. Dorsal foraminal-extraforaminal decompression is challenging because of severe perineural adhesions. Therefore, neural decompression should be focused on the ventral foraminal expansion along the virgin dissection plane between the exiting nerve root and ventral foraminal pathologies. The prominent bony spur and herniated disc were removed using an endoscopic drill and forceps. As the foramen was enlarged, the endoscope was introduced deeper through the caudal-ventral foramen space to explore the extraforaminal and far-out lesions. Postoperatively, neurological deficits of L5 radiculopathy and radiating leg pain improved. The expanded foraminal-extraforaminal space was well maintained without progression of lateral wedging on the one-year follow-up images. We successfully treated recurrent foraminal-extraforaminal stenosis and combined lateral recess stenosis using the full endoscopic interlaminar contralateral approach at the L5-S1 level. This technique may be an alternative surgical method to treat the recurrent foraminal-extraforaminal stenosis in the collapse of the L5-S1 neuroforamen. However, this technique should be considered in highly selected patients unsuitable for fusion operations.

Objective We compared the midterm clinical and radiological outcomes between 2 types of full endoscopic posterior cervical foraminotomy, including conventional posterior endoscopic cervical foraminotomy (PECF) and modified inclined technique for PECF. Methods One of the 2 types of PECF surgery was performed for defined cervical foraminal stenosis. The foraminal expansion ratio and facet resection rate and foraminal stenosis grade were measured using magnetic resonance imaging. Visual analogue scale (VAS) scores for neck and arm pain, neck disability index, MacNab criteria, operation time, hospital stay, and complications, including postoperative dysesthesia, were assessed. Clinical and radiological parameters were compared between the 2 surgical groups. Results There were 49 and 46 patients in the PECF and modified-PECF groups, respectively. The modified-PECF group showed significantly higher expansion of distal foraminal diameter and foraminal height, and a lower facet resection rate compared to PECF group (in all, p

Extraforaminal juxtafacet cyst is rare and present a surgical challenge due to its anatomical location. This study aimed to introduce the surgical technique of interlaminar contralateral endoscopic lumbar foraminotomy (ICELF) for extraforaminal juxtafacet cyst removal and reveal its approach-related benefits. The endoscope was docked on the ipsilateral spinolaminar junction and access the contralateral foraminal area through the contralateral sublaminar space created by the fine drilling. As the foraminal was enlarged by bony drilling, the endoscope was introduced deeper to the extraforaminal area without violation of the foraminal disc. Combined foraminal stenosis was also resolved while exploring the foraminal space. Subsequently, the extraforaminal cyst was safely and entirely removed while exposing the cyst-nerve root adhesion site with an endoscopic view looking up obliquely. Radiating pain in the right leg, back pain, leg hypesthesia, and ankle weakness improved. ICELF for the treatment of extraforaminal JFC can be an alternative surgical method to resolve symptomatic foraminal stenosis and the cyst simultaneously. The entire cyst contour and the site of cyst-nerve root adhesion can be detected without nerve root retraction, and meticulous dissection is possible without violating the cystic wall using the full endoscopic contralateral approach.

Objective The aim of this study was to compare the clinical and radiologic outcomes of 3 types of minimally invasive posterior cervical foraminotomy (PCF): uniportal endoscopic surgery, biportal endoscopic surgery, and microsurgery. Methods Between January 2019 to January 2020, PCF was performed using 3 different approaches to treat foraminal stenosis. The foraminal expansion rate, facet resection rate, and surgical foraminal approach angle were measured using magnetic resonance imaging. Visual analogue scale (VAS) scores for neck and arm pain, neck disability index (NDI), MacNab criteria, operation time, hospital stay, and complications were assessed. Clinical and radiologic parameters were compared among the 3 surgical groups. Results There were 38, 30, and 50 patients in the uniportal endoscopy, biportal endoscopy, and microscopy groups, respectively. Microscopy group displayed significantly higher foraminal expansion compared to uniportal endoscopy group (p=0.001). Facet resection rates and inclination angle for facet joint undercutting were significantly different among the 3 groups. Uniportal endoscopy group had the highest inclination angle and the least facet resection. On the 6 months and final follow-up, VAS scores and NDI were significantly lower in the uniportal endoscopy group than in the microscopy group (p=0.000). Conclusion All 3 types of PCF displayed favorable clinical outcomes and sufficient expansion of the midforaminal area. Two endoscopy groups showed a significantly higher inclination angle for undercutting the facet joint and a lower facet resection rate than the microscopy group. Reduced facet joint resection using an inclinatory approach did not interfere with sufficient foraminal expansion and enhanced the clinical result after 6 months of follow-up.

Abstract Background Advances in minimally invasive surgery have expanded the indications for interlaminar full-endoscopic discectomy. Although the clinical outcomes for this approach may be equivalent to those of conventional microscopic discectomy, the supporting evidence is still based on small, single-center, prospective, and retrospective studies. Therefore, a multicenter randomized controlled trial is warranted. Methods This will be a prospective, multicenter, randomized controlled trial comparing the efficacy and safety of interlaminar full-endoscopic discectomy to those of conventional microscopic discectomy. The trial will enroll 100 participants with a lumbar disc herniation, 50 in each group. The primary outcome will be the Oswestry Disability Index (ODI) score at 12 months post-surgery. Secondary outcomes will be back and leg pain (visual analog scale); the ODI; the EuroQol-5-dimension score; patient satisfaction; and walking distance/time and time to return to daily activities post-surgery. Surgical outcomes will include postoperative drainage, operative time, duration of hospital stay, postoperative creatine kinase level as an indicator of muscle injury, and postoperative scarring. Postoperative magnetic resonance imaging, computed tomography, and simple radiography will be performed to evaluate radiographic outcomes between the two surgical approaches. Surgery-related complications and adverse effects will be evaluated as safety outcomes. A single assessor at each participating hospital, blinded to group allocation, will assess the enrolled participants at baseline, at 2 weeks, and at 3, 6, and 12 months postoperatively. Discussion This trial is designed to determine whether interlaminar full-endoscopic discectomy is clinically comparable to microscopic discectomy to treat lumbar disc herniations. All efforts will be made to reduce bias, including adequate sample size, blinded analyses, and multicenter prospective registration. The outcomes will inform practice, providing the evidence needed for using interlaminar full-endoscopic over microscopic discectomy by confirming the potential of this technique to improve patient satisfaction and clinical outcomes. Trial registration: Clinical Research Information Service; cris.nih.go.kr. (KCT0006277); protocol version (v1, June 8, 2021).

Lumbar spinal stenosis is a common spinal degenerative condition. Minimally invasive interlaminar full-endoscopic decompressive laminectomy provides greater patient satisfaction and faster recovery than open decompressive laminectomy. The aim of our randomized controlled trial will be to compare the safety and efficacy of interlaminar full-endoscopic laminectomy and open decompressive laminectomy. Our trial will include 120 participants (60 per group) who will undergo surgical treatment for lumbar spinal stenosis. The primary outcome will be the Oswestry Disability Index measured at 12 months postoperatively. Secondary patient-reported outcomes will include back and radicular leg pain measured via a visual analog scale; the Oswestry Disability Index; the Euro-QOL-5 Dimensions score measured at 2 weeks and at 3, 6, and 12 months postoperatively; and patient satisfaction. The functional measures will include time to return to daily activities postoperatively and walking distance/time. The surgical outcomes will include postoperative drainage, operation time, duration of hospital stay, postoperative creatine kinase (an indicator of muscle injury) level, and postoperative surgical scarring. Magnetic resonance and computed tomography images and simple radiographs will be obtained for all patients. The safety outcomes will include surgery-related complications and adverse effects. All evaluations will be performed by a single assessor at each participating hospital who will be blinded to group allocation. The evaluations will be conducted preoperatively and at 2 weeks and 3, 6, and 12 months postoperatively. The randomized, multicenter design of the trial, blinding, and justification of the sample size will reduce the risk of bias in our trial. The results of the trial will provide data regarding the use of interlaminar full-endoscopic laminectomy as an alternative to open decompressive laminectomy that results in similar surgical findings with less invasiveness. Trial registration: This trial is registered at cris.nih.go.kr. (KCT0006198; protocol version 1; 27 May 2021).

In recent years, endoscopic spine surgeries have advanced dramatically. Endoscopic spine surgeries are expanding to not only the lumbar spine, but also thoracic and cervical spines. Indications for spinal endoscopic surgery have also been expanded. Central stenosis, lateral recess stenosis, and foraminal stenosis were included in surgical indications of endoscopy. Finally, endoscopic lumbar interbody fusion surgeries have been attempted.

The purpose of this longitudinal follow-up study was to investigate the risk of ischemic stroke nationwide in patients with seropositive rheumatoid arthritis (RA) and controls who were matched in age and sex. Patient data were collected from the National Health Insurance Service (NHIS) Health Screening (HEALS) cohort. Using the International Classification of Diseases code M05 (seropositive RA), with a prescription of any disease-modifying anti-rheumatic drug (DMARD), RA was identified. A total of 2,765 patients and 13,825 control subjects were included in our study. The 12-year incidence of ischemic stroke in each group was calculated using the Kaplan-Meier method. The risk ratio of ischemic stroke was estimated using Cox proportional hazards regression. Sixty-four patients (2.31%) in the seropositive RA group and 512 (3.70%) in the control group experienced ischemic stroke (P < 0.001) during the follow-up period. The hazard ratio of ischemic stroke in the seropositive RA group was 1.32 (95% confidence interval (CI), 1.02-1.73) after adjusting for age and sex. The adjusted hazard ratio of ischemic stroke in the seropositive RA group was 1.40 (95% CI, 1.07-1.82) after adjusting for demographics and comorbid medical disorders. According to the subgroup analysis, the hazard ratios of ischemic stroke risks in the female and hypertensive subgroups were 1.44 (95% CI, 1.05-1.97) and 1.66 (95% CI, 1.16-2.38), respectively. In the non-diabetes and non-dyslipidemia subgroups, the corresponding hazard ratios of ischemic stroke were 1.47 (95% CI, 1.11-1.95) and 1.43 (95% CI, 1.07-1.91). Seropositive RA patients have an increased risk of ischemic stroke. In female, hypertension, non-diabetes, and non-dyslipidemia RA subgroups, even without the traditional risk factors for stroke (except for hypertension), increased the risk, which could be potentially attributed to RA.

Biportal endoscopic transforaminal lumbar interbody fusion (TLIF) may have advantages of minimally invasive fusion surgery as well as those of endoscopic surgery. The purpose of this study was to present the biportal endoscopic TLIF technique along with video presentations and a review of the literature on this technique. Basically, the biportal endoscopic TLIF technique is similar to minimally invasive TLIF with a tubular retractor. There were 2 options in the biportal endoscopic TLIF procedures. The first was the insertion of one long TLIF cage and the other was the insertion of 2 short posterior lumbar interbody fusion (PLIF) cages. After the interbody fusion procedures, percutaneous pedicles screw fixation was performed. Biportal endoscopic TLIF achieved complete neural decompression through laminectomy and facetectomy like conventional TLIF. Endplate preparation was performed completely under a clear and magnified endoscopic view. It was also feasible to insert a large TLIF cage or 2 cages for PLIF without exiting nerve root injury. Biportal endoscopic TLIF might have the advantages of endoscopic surgery as well as minimally invasive fusion surgery. Direct neural decompression, endplate preparation under endoscopic guidance, and the insertion of a large TLIF cage or 2 PLIF cages may be the merits of biportal endoscopic lumbar fusion procedures.

ObjectivesBasal cell carcinoma (BCC) tumors are locally invasive but rarely metastatic. However, aggressive metastatic variants are being increasingly reported in elderly people. Here we investigated the clinical utility of vascular endothelial growth factor (VEGF) as a predictive biomarker for aggressive BCC variants. MethodsThirty-five pathologically confirmed cases of BCC that underwent surgical removal in the Plastic Surgery Department between January 1, 2011 and December 31, 2012 were studied. VEGF expression was analyzed in formalin-fixed paraffin-embedded tumor tissue by immunohistochemical staining. Positive staining was defined as more than 10% of the tumor cells showing immunoreactivity. The associations of VEGF expression with various clinicopathologic parameters were analyzed. ResultsThe face was the most prevalent site (28/35), with 15 cases from the nose, 6 cases from the eyelid, and 5 cases from the cheek. The patients were aged between 41 and 86 years, with a mean age of 69.26 ± 173.903 years. The mean BCC size was 1.34 ± 3.853 cm, with a range of 0.3 cm to 12.0 cm. The mean tumor invasion depth from the basement epidermal membrane was 0.17 ± 0.035 cm, with a range of 0.03 cm to 1.10 cm. A mean of 5.66 ± 20.938 intraoperative frozen section slides were examined. VEGF was not expressed in 14 of the 35 patients (40.0%), whereas 42.9% of the patients had low expression and 17.1% of the patients had high expression. VEGF expression was significantly associated with age (P = 0.022), size (P = 0.030), site (P = 0.013), tumor invasion depth (P = 0.019), and number of intraoperatively frozen sections (P = 0.003). ConclusionsThese results suggest that VEGF expression as assessed by immunohistochemistry can predict aggressive or poor prognosis in BCC.

Abstract Backgrounds Although open lumbar discectomy is a gold standard surgical technique for lumbar disc herniation (LDH), surgery-induced tissue injury may actually become a source of postsurgical pain. Percutaneous endoscopic lumbar discectomy (PELD) is introduced as a minimal invasive spinal technique for LDH. The PELD has gained popularity and shown successful results. The authors report the clinical usefulness of the PELD technique in two patients with the serial multilevel LDHs. Case presentations A 32-year-old man suffered from radicular pain at the L5 dermatome due to the down migrated soft LDH at the L4–5 level. The PELD was performed to remove the ruptured fragments, yielding a complete decompression of the L5 nerve root. Four years later, he visited the clinic because of right leg radiating pain along the S1 dermatome. An MRI scan revealed the LDH at the L5-S1 level. The PELD with foraminoplasty was also performed successfully at the L5-S1 level. Two months after the second PELD, he visited the clinic again because of severe pain along the left L4 dermatome; consequently, the PELD was also performed at the L3–4 level without any complications. A 34-year-old man presented with radiating pain in the back and both legs at the L5 dermatome. The MR images show a disc extrusion at the L4–5. The patient underwent the PELD at the L4–5 via the left approach. After the PELD, the back and leg pain both improved. One year later, the patient suffered from severe pain in the back and the left anterior thigh. The MR images show a left paramedian LDH at the L2–3. After the PELD was performed at the L2–3, the pain was relieved. The final MR images show no signs of any aggravated degeneration of the intervertebral discs or the facet joints at all of the treated levels. Conclusion When multiple episodes of LDH occur in a patient’s life span, PELD could be considered as an alternative good technique to treat LDH in each step by preserving normal anatomic structures.

Objective Percutaneous uniportal endoscopic surgery is comparable to conventional open surgery and maintains the surrounding structures, but it has restrictive indications and technical difficulties in sufficient decompression. Percutaneous biportal endoscopic surgery (PBES) can compensate the shortcomings and provide sufficient decompression safely. The purpose of this study is to introduce PBES technique and to report clinical outcome. Methods Seventeen consecutive patients who underwent PBES for spinal stenosis or disc herniation were enrolled for this study. The technique was based on two routes; endoscopic view portal and working portal. Clinical outcomes were assessed using visual analogue scale (VAS) and modified Macnab’s criteria. Results There were 7 female and 10 male patients whose age ranged from 33 to 80 years old (mean 53 years). A total of 10 patients underwent decompression and discectomy for herniated intervertebral disc (HIVD), and 7 patients underwent laminectomy and foraminotomy for lumbar spinal stenosis. The mean follow up period was 8.3 months (6-12 months). The mean VAS scores for back pain preoperatively and postoperatively at the 1 month and 6 month follow-ups were 6.6±1.8, 2.8±2.0, and 2.5±2.0, respectively. The mean VAS scores for leg pain preoperatively and at 1 month and 6 month follow-ups were 7.6±1.9, 1.7±1.3 and 1.8±1.1, respectively. The outcome of the procedure was excellent in 8 patients and good in 9 patients according to the modified Macnab’s criteria. Conclusion PBES can achieve effective decompression and show comparable results with conventional open surgery.

Synovial cyst is an extradural mass that compresses nerve root or thecal sac. Surgical excision with partial hemilaminectomy and medial facetectomy is commonly used for synovial cyst. Remarkable advancements in endoscopic spinal surgery have led to successful outcomes comparable to conventional open surgery. Here we introduce percutaneous endoscopic lumbar foraminoplasty for resecting synovial cyst as a minimal invasive technique. A 59-year-old woman presented with radicular pain at left L5 dermatome. Magnetic resonance images demonstrated a synovial cyst at left L4-5 facet joint and degenerative spondylolisthesis on L4-5. Under endoscopy, synovial cyst was removed by piecemeal method after transforaminal endoscopic foraminoplasty that removed part of superior facet. Her symptoms were relieved and the patient was discharged the next day. Therefore, percutaneous endoscopic lumbar foraminoplasty can be used as a minimally invasive surgical option for synovial cyst. It may provide less traumatization and affect less postoperative instability.

Microdiscectomy for the upward migration of upper lumbar herniated discs has a high risk of isthmus and facet injury. Fully endoscopic transforaminal discectomy can preserve normal bony structures during discectomy. The purpose of this study was to assess the clinical and radiological outcomes of fully endoscopic transforaminal discectomy for upward migrated upper lumbar herniated discs. All patients had upward migrated disc herniation from L1–L2 to L3–L4 levels and were treated using fully endoscopic transforaminal discectomy under local anesthesia. All enrolled patients were monitored for more than 12 months. Clinical outcomes were assessed using the Oswestry Disability Index (ODI) and visual analog scale (VAS) of pain. Surgery-related complications were analyzed. In addition, radiological outcomes were investigated using postoperative magnetic resonance imaging (MRI) and lumbar dynamic X-ray. Twenty-eight patients were enrolled in this study. ODI and VAS significantly decreased after endoscopic transforaminal discectomy. Migrated ruptured disc particles were completely removed and confirmed on postoperative MRI in 26 of the 28 patients. Even though small remnant disc particles were detected in two patients, symptoms improved after endoscopic transforaminal discectomy. Early recurrence of herniated disc occurred at the operated segment in one patient. There were no significant complications associated with fully endoscopic transforaminal discectomy. Three patients experienced a postoperative transient tingling sensation and numbness of the leg. Fully endoscopic transforaminal lumbar discectomy may be an effective and alternative treatment option for upward migrated disc herniation in the upper lumbar area. In addition, fully endoscopic transforaminal lumbar discectomy may prevent complications associated with general endotracheal anesthesia and injuries of the isthmus and the facet joint.

The toxicity of Pinus densiflora (red pine) hydrodistillate, its 19 constituents and 28 structurally related compounds against early third-instar larvae of Aedes albopictus (Ae. albopictus), Aedes aegypti (Ae. aegypti) and Culex pipiens palles (Cx. p. pallens) was examined using direct-contact bioassays. The efficacy of active compounds was further evaluated in semi-field bioassays using field-collected larval Cx. p. pallens. Results were compared with those of two synthetic larvicides, temephos and fenthion. In laboratory bioassays, Pinus densiflora hydrodistillate was found to have 24 h LC50 values of 20.33, 21.01 and 22.36 mg/L against larval Ae. albopictus, Ae. aegypti and Cx. p. pallens respectively. Among the identified compounds, thymol, δ-3-carene and (+)-limonene exhibited the highest toxicity against all three mosquito species. These active compounds were found to be nearly equally effective in field trials as well. In vitro bioassays were conducted to examine the acetylcholinesterase (AChE) inhibitory activity of 10 selected compounds. Results showed that there is a noticeable correlation between larvicidal activity and AChE inhibitory activity. In light of global efforts to find alternatives for currently used insecticides against disease vector mosquitoes, Pinus densiflora hydrodistillate and its constituents merit further research as potential mosquito larvicides.