Surgical and Radiologic Anatomy最新文献

Background: Cervical fixation is a common treatment for conditions like vertebral fractures, osteosarcoma, osteomyelitis, arthritis, and congenital disorders. The study was designed to assess the occurrence of high-riding vertebral artery (HRVA), narrow C2 pedicles (NC2P) and ponticulus posticus (PP), which pose risks of injuring vertebral artery (VA) during screw placement in cervical fixation procedures.

Methods: The study examined the prevalence of HRVA, NC2P and PP in 382 pedicle sides of the C2 vertebra using computed tomographic angiography scans. Specific measurements were taken, including the internal height (C2InH), and isthmus height (C2IsH) of C2, as well as NC2P width.

Results: HRVA was identified by specific measurements: C2IsH of ≤ 5 mm and/or C2InHof ≤ 2 mm. NC2P was defined as NC2P width ≤ 4 mm. The reliability between observers and within the same observer, along with the consistency across different software, was assessed. At least one HRVA was found in 9.6% of patients and at least one NC2P in 13% of patients. Females demonstrated higher rates of HRVA and NC2Ps on the left side, with right-side figures at 10.5% and 11.7% for HRVA and NC2Ps respectively, and left side figures at 14.1% for both. Males exhibited a reserve pattern, with higher rates on the right side, marked by 10.3% HRVA and 15% NC2Ps, compared to 5.6% and 11.3% on the left. Furthermore, males showed a significantly higher occurrence of NC2Ps over HRVA on both sides. The presence of PP with NC2Ps detected in 44% of cases, and with HRVA in 16% of cases, a difference found to be statistically significant.

Conclusions: The digital models incorporating HRVA, NC2P, and PP facilitated a comprehensive analysis of the VA pattern, assessment of the virtual screw trajectory line for VA pedicles, and the designation of specific regions during the procedure, ensuring increased safety planning instrumentation.

Purpose: The eight typical External Carotid Artery (ECA) branches are the superior thyroid artery, ascending pharyngeal artery, lingual artery, facial artery, occipital artery, posterior auricular artery, maxillary artery, and superficial temporal artery. The Internal Carotid Artery (ICA) has no branches in the cervical region before entering the carotid canal. We identified a variant of the Occipital Artery (OA) and Ascending Pharyngeal Artery (APA) originating in the cervical portion of the ICA and wish to explore the clinical implications this variation may have.

Methods: Between August and December 2023, 28 formaldehyde donors were dissected in the anatomy course for first-year medical and physician assistant students at the Creighton University School of Medicine, Phoenix campus.

Results: In one donor, dissection of the right common carotid artery (CCA) revealed a variation of the ECA branches. Two branches were found on the proximal portion of the ICA. After tracing the branches cranially, we identified these as the OA and APA. These two arteries typically originate from the ECA. The bifurcation angle was observed to be nearly 180 degrees. This variation was only observed on the right side.

Conclusion: As the prevalence of this variation has only been described in one study, reporting at 0.14%, documentation and education of this anatomy aids surgeons and interventional radiologists in head and neck procedures. Exploring the paths of these ectopic arteries promotes informed decision making and risk stratification for carotid endarterectomy, arterial embolization, bypass procedures, and arterial harvesting. Furthermore, performing thorough imaging such as CT angiograms on patients preoperatively provides better foresight to minimize complications.

Purpose: Mesial temporal lobe epilepsy is a common form of focal drug resistant epilepsy in adults. Various mesial temporal lobe structures are integral in the genesis of temporal seizures and the hippocampal sclerosis is the primary neuropathological finding in these cases. Surgical treatment is considered the preferred management. This study aims to analyze the anatomical and surgical aspects of various resection techniques of selective amygdalohippocampectomy (SAHE)and clarify the critical anatomical landmarks and technical nuances associated which each method.

Methods: Through dissection of five human head and brain specimens we evaluated three primary surgical approaches for SAHE-transsylvian, transcortical, and subtemporal - and additionally discussed laser interstitial thermal therapy (LITT). We examined the anatomical considerations of the temporal lobe and its white matter tracts, as well as the technical aspects of each approach.

Results: The transcortical approach provides direct access to mesial structures but requires precise placement of the corticotomy based on hemisphere dominance to avoid arcuate fascicle and optic radiation. The subtemporal approach preserves all above white matter tracts but may risk interruption of the inferior longitudinal fasciculus. The transsylvian approach allows for comprehensive exposure but poses risks to tracts within limen insulae, namely uncinate and inferior fronto - occipital fascicles. Additionally, there is a risk to middle cerebral artery and its branches. LITT offers a minimally invasive alternative with comparable outcomes and reduced risk of cognitive side effects.

Conclusion: Selective amygdalohippocampectomy and its variants, including LITT, are surgical strategies for managing mesial temporal lobe epilepsy. Each approach has distinct anatomical and technical considerations that influence the choice of a technique. Due to complex anatomy of temporal lobe and white matter tracts variability more research is essential for achieving favourable outcomes.

Purpose: A case of frontal branch of the left middle meningeal artery (MMA) arising from the ophthalmic artery (OA).

Methods: A 73-year-old woman with vertigo underwent cranial magnetic resonance (MR) imaging and cranial MR angiography using a 1.5-Tesla scanner. MR angiography was performed using a standard 3-dimensional time-of-flight technique.

Results: MR imaging revealed multiple small ischemic white matter lesions. Maximum-intensity-projection (MIP) MR angiography showed no pathological arterial lesions such as steno-occlusive lesions; however, the left MMA arose from the OA. On MR angiographic source images, the tiny left MMA passed through the foramen spinosum and supplied the parieto-occipital trunk of the MMA. Thus, the left MMA arising from the OA was considered the frontal branch. The right MMA normally supplies both the frontal branch and the parieto-occipital trunk.

Conclusion: We present a case of MMA originating from the OA. The prevalence of this variation has been reported to be approximately 0.5%, which is not very rare. However, most reported cases are diagnosed using catheter angiography or cadaver dissection. We diagnosed this variation using MR angiography. Careful observation of MR angiographic source images is useful and important for identifying tiny arteries that cannot be visualized using MIP MR angiography.

Purpose: To describe a case of large arterial ring formed by a duplicate origin of the right middle cerebral artery (MCA) associated with a frontal branch arising from the superior channel of the ring (main MCA) using magnetic resonance (MR) angiography.

Methods: An 81-year-old man with spinocerebellar degeneration underwent cranial MR imaging and MR angiography using a 1.5-Tesla scanner. MR angiography was performed using a standard 3-dimensional time-of-flight technique.

Results: MR imaging showed cerebellar atrophy and multiple cerebral white matter lesions. Regarding family history, he was diagnosed with Machado-Joseph disease. On MR angiography, an anomalous artery arose from the lateral wall of the supraclinoid segment of the right internal carotid artery (ICA) and fused with the main MCA, forming a large arterial ring. Thus, the anomalous artery was diagnosed as a duplicate origin of the MCA and not a duplicated MCA. The frontal branch of the MCA arose from the superior channel of the arterial ring (main MCA).

Conclusion: This variation is called "segmental duplication of the MCA." However, this term may be confused with a duplicate origin or fenestration of the proximal M1 segment of the MCA. We report the first case of this combined variation diagnosed using MR angiography.

Purpose: Anatomical associations between the frontal sinus and anterior skull base must be carefully understood in preoperative imaging to minimize surgical complications. This study aims to investigate the relationship between frontal sinus volume and lateral lamella angle.

Methods: 150 computed tomography scans of paranasal sinuses (300 sides) were retrospectively reviewed. Pneumatization patterns were classified according to volume using a three-dimensional reconstruction analysis of the frontal sinuses. The angle formed between the lateral lamella and the horizontal plane in continuation with the cribriform plate was measured and grouped according to Gera classification based on the hypothetical risk of iatrogenic injury. Analysis of these measurements was conducted.

Results: A positive correlation was found between frontal sinus volume and lateral lamella angle. Hyperplastic frontal sinuses were the most prevalent followed by middle-sized sinuses. 5% of the frontal sinuses were aplastic. Lateral lamella angles ranging from 45 to 80 degrees (Gera class II) were the most common. Aplastic and hypoplastic frontal sinuses were common in subjects with less than 45 degrees lateral lamella angles (Gera class III). Males had significantly higher frontal sinus volumes and lateral lamella angles than females, while the influence of age was insignificant. Lateral lamella angles were significantly higher on the left side.

Conclusion: The frontal sinus volume affects the lateral lamella angle. Larger frontal sinuses are associated with higher lateral lamella angles and vice versa. Understanding this anatomical relationship can help prevent surgical complications.

Purpose: Our aim was to analyze the developmental changes in the morphology of the internal auditory canal (IAC) in both children and adults to gain a three-dimensional understanding that could enhance various surgical approaches.

Methods: We retrospectively investigated 120 ears of 60 patients, ranging in age from birth to adulthood, using 3D-reconstruction data from normal temporal bone CT scans. The volume of the IAC in the temporal bone was reconstructed in 3D using Vworks version 4.0 (CyberMed, Seoul, Republic of Korea). Data were classified and evaluated by age group. IAC parameters were measured in the 3D objects using the axial, coronal, and sagittal sections of the CT scans.

Results: The IAC volume significantly increased with aging from group 1 to group 2 (P = 0.01). The IAC volume also significantly correlated with the studied parameters (P = 0.001, for all). The Spearman's rho values between the volume of IAC and the six parameters were as follows: Wp (r = 0.619), Wv (r = 0.763), Wm (r = 0.697), Dp (r = 0.541), Dm (r = 0.692), and Lpf (r = 0.659).

Conclusions: IAC volume continues to develop through adolescence. Understanding the normal growth pattern and three-dimensional morphology of the IAC would be helpful for different surgical approaches.

Purpose: This study aimed to examine and analyze the presence of sexual dimorphism and symmetry/asymmetry in fixed cadaveric heads and their contributions to clinical practice.

Methods: Measurements were conducted on 6 cadavers and 24 fixed cadaveric heads (n = 30) using a digital microcaliper to assess cranial dimensions, including surgical landmarks, facial index (FI), orbital index (OI), and the danger triangle of the face, offering crucial references for surgeons during surgical interventions.

Results: Analyses were conducted on cadavers consisting of 10 females (33.3%) and 20 males (66.7%). Males demonstrated significantly higher values than females in terms of Zy-Zy (Zy = Zygion), nasal body, and width/length of the columella. Hyperleptoprosop types were the most frequently observed, followed by the leptoprosop type. Females exhibited megaseme characteristics according to OI on both sides. Additionally, the danger triangle of the face was greater in males compared than in females, suggesting a higher risk of infection in this region among males.

Conclusion: The observed sex differences in facial and nasal dimensions, along with facial indices, are crucial for customizing surgical procedures to individual patients. For example, the greater distance in the danger triangle among males highlights the importance of considering anatomical variations to avoid complications, such as septic cavernous sinus thrombosis. Integrating these measurements into preoperative planning can enhance the precision of facial reconstruction and aesthetic surgeries, thereby improving patient outcomes and safety.

Purpose: The variable positions of the appendix can mislead surgeons and physicians to a wrong diagnosis. When appendicitis happens in subhepatic caecum, it can be misdiagnosed and can lead to severe complications during surgical procedures. Therefore, this study aimed to understand the histomorphometric development of the appendix and caecum and to identify when lymphoid follicles appear in the appendix during fetal life.

Methods: The study was conducted on a total of 50 fetuses. The caecum and appendix were carefully dissected. Their position and various measurements were observed. Afterwards, the appendix was taken out for histological processing. All three layers, mucosa, submucosa, and muscularis externa were measured using Image Analyzer Software Image Pro Premiere 9.1, and the appearance of lymphoid follicles was also examined. Results were analyzed using SPSS statistical software.

Results: During the 1st, 2nd, and 3rd trimesters the most common caecum type was type 1: as a lengthy tube, type 3: The lateral wall expanded more, thus it has an asymmetric saccule, and type 4: adult-like caecum. The caecum was mostly situated in the right lumbar region in the 2nd and 3rd trimesters. In the 1st trimester, it was subhepatic in position. The most common position of the appendix was 11 o'clock in 1st and 3rd trimesters. 2nd trimester's most common position of the appendix was 12 o'clock. The thickness of the mucosa, submucosa, and the muscularis externa increases as the trimester increases. The lymphoid follicles have appeared during the 2nd trimester.

Conclusion: The knowledge from this study will be useful in the diagnosis and treatment of malformations, pathology, and anomalies of the caecum and appendix due to congenital causes.

Purpose: This study investigated the internal carotid artery (ICA) and jugular bulb (JB) structures in terms of lateral temporal bone resection using 3D computed tomography (CT).

Methods: We retrospectively investigated 80 ears of 40 patients using 3D reconstruction data from normal temporal bone CT. Ten critical points (P) in the temporal bone were marked in the 3D object with reference to the axial, coronal, and sagittal images of the CT scans. An imaginary plane of the facial nerve (PLf) course was also reconstructed in relation to the three points of the chorda-facial junction, P5 (second genu), and P3 (cochleariform) process.

Results: The distances (mean ± SD; mm) from points P3 to P1 (the highest level of the JB) and P2 (the posterior wall of the ascending petrous IAC at the level of the Eustachian tube) were 12.03 ± 2.56 and 9.79 ± 1.78, respectively. The distances from point P4 (chorda-facial junction) to P1 and P2 were 10.98 ± 2.70 and 17.66 ± 2.26, respectively. The angles (mean ± SD; degree) between the PLf to the line from Pa (point of the anterior bony canal) to P3 and P4 were 17.80 ± 10.05º and 8.93 ± 5.37º, respectively. The angles between the PLf to the line from P3 to P1 and P2 were - 36.35 ± 13.28º and - 24.78 ± 13.91º, respectively. The angles between the PLf to the line from P4 to P1 and P2 respectively were - 40.35 ± 15.37º and - 13.34 ± 7.63º.

Conclusions: Understanding the anatomical relationships of P1 and P2 at P3 and P4 can be helpful in preventing iatrogenic trauma of the ICA and JB.