Surgical and Radiologic Anatomy最新文献

Purpose: This study aimed to evaluate the distance for the safe and efficient insertion of percutaneous pedicle screws (PPSs) in lumbar fixation surgery.

Methods: On lumbar computed tomography thin-slice images parallel to the cranial vertebral endplate, two different insertion points of the PPS were defined: (1) the lateral wall of the pedicle (defined as the LP) and (2) the angle between the transverse process and superior articular process (TS). From these points, we measured the distance to the inner wall of the pedicle (A) and the posterior wall of the vertebral body (B). The distance was measured bilaterally from L1 to L5 of consecutive 60 patients.

Results: The results of PL-A (the mean distance ± standard deviation) from the L1 level to the L5 were 17.9 ± 3.0, 18.1 ± 2.9, 18.9 ± 3.1, 18.7 ± 3.4, and 19.9 ± 3.3 mm, respectively. Those of PL-B were 24.1 ± 3.5, 23.2 ± 3.4, 23.0 ± 3.8, 22.1 ± 4.1, and 21.9 ± 3.8 mm. The results of TS-A were 17.9 ± 2.6 mm, 17.6 ± 2.2, 18.0 ± 2.3, 16.3 ± 2.2, and 17.1 ± 2.3, whereas those of TS-B were 22.8 ± 2.6 mm, 21.6 ± 2.3, 21.2 ± 2.1, 18.6 ± 2.1, and 18.3 ± 2.2, respectively. Moreover, the PL-A, PL-B, TS-A, and TS-B of all L1-L5 were 18.7 ± 3.2, 22.9 ± 3.8, 17.4 ± 2.4, and 20.5 ± 2.9 mm.

Conclusion: This study can contribute to the safe and efficient insertion of the lumbar PPS.

Purpose: This study aimed to perform a morphometric analysis of the main superficial anastomotic veins of the brain the vein of Trolard (VT), vein of Labbé (VL), and superficial Sylvian vein (SSV) using magnetic resonance venography (MRV), and to compare the findings with the literature to assess clinical and surgical implications.

Methods: MRV scans of 154 individuals (105 females, 49 males; mean age: 42.12 ± 16.39 years) obtained between 2020 and 2024 were retrospectively analyzed. The presence, length, midpoint diameter, course, drainage pattern, dominance, and interconnections of the VT, VL, and SSV were evaluated bilaterally. Statistical analyses included chi-square, independent t-test, Mann-Whitney U, Pearson correlation, and Holm-Bonferroni correction.

Results: VT was the most prevalent vein, observed in 88.3% of right and 76.6% of left hemispheres, most often located in the postcentral region. VL was present in 74.0% (right) and 66.9% (left), draining mainly into the transverse sinus. SSV was identified in 74.3% (right) and 63.6% (left). Significant associations were found between right VL and SSV (p = 0.0003) and between left VT and right SSV (p = 0.0385, not significant after correction). VT predominated in the right hemisphere and VL in the left. No correlation was found between age and morphometric parameters.

Conclusion: Superficial cerebral veins exhibit marked anatomical variability. Understanding their course and drainage is essential for neurosurgical planning, particularly in lateral and trans-Sylvian approaches. This study provides updated morphometric data to help minimize venous injury and support future anatomical and surgical research.

Purpose: To report a case of tongue cancer with an exceptionally rare bilateral retropharyngeal course of the common, internal, and external carotid arteries, and to underscore the critical role of preoperative imaging for performing a safe neck dissection.

Methods: An 81-year-old woman was diagnosed with squamous cell carcinoma of the right tongue. Preoperative contrast-enhanced computed tomography revealed a unique vascular anomaly, with the bilateral carotid systems coursing retropharyngeally. Based on this detailed radiological assessment, she underwent a partial glossectomy and a modified radical neck dissection under general anesthesia.

Results: Guided by the preoperative three-dimensional anatomical evaluation, the carotid arteries were identified and preserved early in the procedure, which was completed without abnormal hemorrhage (estimated blood loss: 76 mL). The final pathological diagnosis was pT2N0M0. The patient's postoperative course was complicated by multiorgan failure secondary to sepsis, unrelated to any vascular injury, and she ultimately expired. The cervical wound healing was uneventful.

Conclusion: Neck dissection can be performed safely even in the presence of complex carotid artery anomalies. Meticulous preoperative radiological evaluation and tailored surgical planning are indispensable for averting catastrophic vascular complications. Head and neck surgeons must maintain a high index of suspicion for such anatomical variations.

Purpose: This study aimed to clarify the morphological characteristics of the retrocalcaneal bursal wedge of Kager's fat pad (KFP-W).

Methods: Fifty legs from 27 cadavers were examined. The KFP-W was categorized as either a single-lobule or double-lobule type based on the presence or absence of separation into medial and lateral lobules. Separation of the retrocalcaneal bursa was evaluated based on the presence of intrabursal connective tissue. The length, width, and thickness of the KFP-W were also measured.

Results: The single- and double-lobule types were each observed in 25 ankles (50%). In the single-lobule type, the KFP-W was positioned laterally on the superior facet, leaving a portion of the medial aspect of the facet uncovered, and no separation of the retrocalcaneal bursa was observed. In the double-lobule type, bursal separation was present in 16 ankles (64%), and the lateral lobule was significantly longer, wider, and thicker than the medial lobule (p < 0.05).

Conclusion: These findings suggest that the KFP-W is primarily situated lateral to the Achilles tendon insertion, with a smaller or absent structure medially. Therefore, the medial region may exhibit reduced shock-absorbing capacity due to the less prominent KFP-W.

Purpose: The brain lymphatic vessels (LV) drain fluids, metabolic waste, and immune cells. The abnormal accumulation of toxic substances causes neurodegenerative, cerebrovascular diseases, and brain tumors. Despite their intracranial importance, the precise extracranial exit routes of brain LVs remain poorly characterized. We evaluated the presence of LVs in the dural samples overlying the foramina/canals (superior orbital fissure, foramen rotundum, foramen ovale, Meckel's cave, internal acoustic meatus, foramen lacerum, jugular foramen, and hypoglossal canal) using immunohistochemistry.

Methods: Samples from six human cadavers were stained with Podoplanin, LYVE-1 (LV endothelial markers), and CD31 (vascular endothelial marker).

Results: The LVs were observed in all the dura samples except the internal acoustic meatus. The dura overlying the Meckel's cave had the largest LVs, and the smallest ones were observed in the superior orbital fissure. Further, the dura overlying the jugular foramen had the largest FCs, and the smallest ones were observed in Meckel's cave. The diameters of the LVs may indicate their efficiency in the transfer of lymphatic fluid. Fluid channels of varying diameters were closely localized to the LVs.

Conclusion: Our findings can increase the understanding of how LVs exit the skull and contribute to the neuropathophysiological processes. Knowledge of the lymphatic network is important for identifying metastatic sites of various cancers. Furthermore, special attention should be given during regional surgery to preserve lymphatic drainage.

Purpose: The vertical location of the basilar artery bifurcation (BAB) is a crucial factor in determining the best surgical approach for basilar tip (BAT) aneurysms. Although anatomical variants, such as the fetal-type posterior cerebral artery (FPCA), have been linked to aneurysm formation, their impact on BAB height remains unclear.

Methods: A retrospective anatomical-imaging analysis of 250 high-resolution computed tomography angiograms (CTAs) was conducted to measure the vertical distance from the BAT to the clinoidal line (CL). A dominant posterior communicating artery and/or a hypoplastic or absent P1 segment defines the FPCA.

Results: BATs were classified into four types based on their BAT-CL distance, with Type 2 BATs (within ± 5 mm of the CL) being the most common. The mean BAT-CL distance was + 2.88 ± 4.8 mm. An FPCA was identified in 74 patients (29.6%). The BAT was significantly lower in all fetal-type subgroups than in patients with typical PCA anatomy (p < 0.005). Bilateral FPCA exhibited the lowest BAT-CL distance (- 0.9 ± 3.2 mm). An FPCA is significantly associated with a caudally positioned BAT.

Conclusions: This finding can assist in surgical planning by predicting aneurysm height based on vascular configuration. In such cases, the pretemporal trans-cavernous approach through extended pterional craniotomy may offer safer and more direct access, thereby reducing surgical morbidity. These results support incorporating vascular variants in preoperative assessments to optimize personalized neurosurgical strategies.

Purpose: To investigate the association between the anatomical course of the optic nerve within the sphenoid and posterior ethmoid sinuses (Delano classification) and anterior skull base morphology, particularly lateral lamella length and olfactory fossa depth.

Methods: Paranasal sinus CT scans from 192 patients (384 hemi-sinuses) were retrospectively reviewed. The course of the optic nerve was categorized using the Delano classification (types 1-4). Lateral lamella length and Keros classification were assessed for each case. Statistical comparisons were performed using ANOVA, post-hoc Tukey tests, and Chi-square analysis.

Results: Lateral lamella length significantly differed among the Delano types (p = 0.001). Delano type 3 and type 4 sinuses demonstrated significantly longer lateral lamella compared to type 1 (p = 0.026 and p = 0.016, respectively). Additionally, a significant variation in Keros classification was observed across Delano groups (p = 0.025), with higher Delano types showing increased prevalence of Keros type 3. These findings suggest that optic nerve protrusion is associated with elongation of the lateral lamella and deepening of the olfactory fossa.

Conclusion: This is the first study to demonstrate a significant anatomical correlation between Delano classification and anterior skull base morphology. As optic nerve protrusion into the sphenoid sinus increases, adjacent skull base structures-particularly the lateral lamella-become elongated, potentially heightening the risk of iatrogenic injury during endoscopic sinus surgery. Combined use of Keros and Delano classifications in preoperative imaging may enhance surgical risk stratification and improve patient safety.

Background: The accessory soleus muscle (ASM) is a rare anatomical variant and the most common accessory muscle in the leg/ankle region. Though asymptomatic in most cases, ASM could exhibit clinical manifestations leading to medical consultation. Since no evidence-based synthesis has been conducted yet, this review aims to collate pooled quantitative data on the clinical presentation and management of ASM.

Methods: The electronic databases of Medline and Embase were searched from inception, met the inclusion criteria. Only clinical cases of symptomatic ASM were included. Clinical and cadaveric incidental findings of ASM were excluded.

Results: Forty-one articles met the inclusion criteria, comprising 134 ASM in 122 patients. The clinical presentation of the ASM was as follows: exertional pain (60%), posteromedial ankle swelling (59%), foot numbness/dysesthesia (5.2%), soft non-tender mass (30%), a tender mass in 9%, a soft mass that becomes hard on plantarflexion (44%), and positive Tinnel's sign (11.2%). The diagnostic modalities used were: x-rays (62.7%), MRI (52.2%), CT scan (24.6%), ultrasound (12.7%) and EMG studies (13.4%). Out of 128 treated cases, conservative management was used in 36.7%, and surgery in 50% of cases including fasciotomy in 22.6%, excision in 20.3%, posterior tibial nerve decompression in 7.8%, and a combined procedure in 1.7%. Regardless of the treatment modality, all surgical patients were satisfied.

Conclusions: The findings of this review would help clinicians to better recognize, diagnose and treat the rare condition of a symptomatic accessory soleus muscle.