计算机辅助导航技术在鼻窦及鼻颅底手术中的应用

目的:探讨计算机辅助导航技术在鼻窦及鼻颅底手术中的应用价值。方法:49例患者(复发性鼻窦炎、鼻息肉25例,鼻腔鼻窦肿瘤9例,脑脊液鼻漏7例,脑膜脑膨出2例,先天性后鼻孔闭锁4例,垂体瘤1例,中颅窝底异物1例)均在计算机辅助导航下行鼻内镜手术。结果:计算机辅助导航术前准备时间为5～13min,平均7min,靶点误差≤1.5mm。49例患者均顺利完成手术,无并发症出现。结论:计算机辅助导航系统有助于术者正确判断鼻窦、颅底及相邻的解剖标志,可提高手术的精确性和安全性,减少术中及术后并发症的发生。     

Submillimetrische 3D-Navigation im Felsenbein

BACKGROUND: In order to evaluate the possible submillimeter application accuracy in computer-aided navigation in the petrous bone, we performed a set of approximately 3,000 measurements on a specially prepared anatomic specimen using the Zeiss STN intraoperative navigation system. This allowed direct measurements of relevant anatomic structures in and around the petrous bone which are usually not directly accessible. RESULTS: We found that the best results can be achieved by exploiting contemporary multislice CT-imaging with 0.5 mm slice thickness and by direct radiologic imaging of the petrous bone; additionally, an extrinsic marker structure, the VBH-referencing element, served as an extension of the applied surface markers for the "patient-to-image" referencing procedure. Interestingly, the additional use of a surface registration, as provided by the STN-navigation system, to potentially optimize the registration, did not improve the results. In the best case, i.e. with high-resolution CT-imaging, 0.5 mm slice spacing, the use of surface markers, and the extrinsic referencing structure applied, an absolute difference between the calculated and actual position of the probe was 0.42+/-0.69 mm. CONCLUSIONS: These results show that intraoperative 3-D navigation can be successfully transferred to a clinical application in the petrous bone or at the cerebellopontine angle with satisfactory accuracy in this highly sensitive anatomic region, even if only a restricted area of the patient can be used for the referencing procedure.     

影像导航下鼻内镜手术58例临床分析

OBJECTIVE: To evaluate the availability and our experience of intraoperative image-guidance in endoscopic nasal surgery. METHODS: Fifty-eight cases of endoscopic nasal surgery with intraoperative image-guidance were retrospectively reviewed, including 39 cases of chronic sinusitis with or without nasal polyp; 3 cases of necrotizing maxillary sinusitis; 6 cases of sphenoid sinus cyst; 2 cases of nasopharyngeal angiofibroma; 1 case of cranio-nasal meningioma; 1 case of traumatic cerebrospinal rhinorrhea; 1 case of traumatic optic nerve lesion. All patients were operated on with Brain Lab operation imaging navigation system and nasal endoscope. RESULTS: The preoperative preparatory time would take 10-20 minutes, including coordination, head holder localization, conventional instrument registration. In our cases, the localization accuracy between 3-D image landmarks of navigation system and actual anatomical landmarks was less than 1.5 mm. The optic nerve and other anatomical points could be orientated accurately in intraoperative procedures. No complication occurred. CONCLUSIONS: Nasal endoscope combined with image-guidance systems provides accurate anatomical localization of nasal cavity, sinuses and anterior skull base with enlarged operation field. It is possible for surgeons to observe the surrounding important anatomical structures during endoscopic nasal surgery. It could increase the effectiveness and decrease surgical complications, especially in complicated cases.     

Schädelbasischirurgie mit einem optoelektrischen Navigationssystem

BACKGROUND AND OBJECTIVE: The exact localization of pathological anatomy is the basis of a successful operation. Malformations, tumors, or previous operations can make intraoperative orientation considerably more difficult. Navigation systems can be useful tools in such cases. METHODS: The OTS is an optoelectrical navigation system which was used on 34 patients with disorders of the skull base region. Clinical accuracy, practicability, and intraoperative usefulness of the system were evaluated. RESULTS: In clinical use, an accuracy of approximately 1.5 mm could only be achieved with the use of head fixation and bone-anchored reference markers. When using the VBH mouthpiece for dynamic referencing with flexible head positioning, deviations of less than 2 mm were observed. The preoperative preparation time was 15-25 min, depending on the operation schedule. CONCLUSIONS: The intraoperative orientation system represents a significant aid for orientation, particularly where anatomical alterations are present. Further modifications to improve both accuracy and the integration of the system into working practice are, however, essential.     

电磁导航技术在鼻颅底手术中的应用

摘要：目的探讨电磁导航技术在鼻颅底手术中的临床应用。方法收集 2017 年 8月—2019 年 2月应用电磁导航技术行 15例鼻颅底手术,患者病变范围涉及蝶窦、鞍区、咽旁隙、颈静脉孔区、筛顶、蝶骨平台等解剖区域。术前均完善 CT、MRI 等影像学资料,录入导航系统行三维重建,鼻内镜下进行手术,涉及复杂、重要解剖结构时使用导航系统进行定位。结果15例手术中1例鼻颅底纤维血管瘤术中出血约1 000 ml,余手术出血均可控。15例手术术中均未出现重要结构损伤,术后无严重并发症。15 例患者术后随访3~20个月,1例鼻颅底腺样囊性癌患者术后12个月复查考虑肿瘤复发。结论电磁导航技术应用于鼻颅底手术中,安全、精准,手术并发症少,特别适用于解剖结果变异、修正鼻内镜手术、病变广泛的恶性肿瘤患者。     

The application of an optical navigation system in endonasal sinus surgery

BACKGROUND: There are several CAS-systems in use in modern endonasal sinus surgery. The VectorVision Compact is the first optoelectrical system especially designed for such surgery.This paper investigates its reliability and practicability. PATIENTS AND METHODS: The system was used for intraoperative navigation in 60 patients suffering from chronic rhinosinusitis.The accuracy was measured by visual estimation and compared with other navigated systems. RESULTS: The accuracy was 1.9 mm which is comparable to other systems on the market. Navigation was successful and reliable in 83.3% of the patients.Problems occurred mainly due to loss of sight of the referencing balls and when using other surgical instruments. CONCLUSION: The VectorVision Compact was adequate for endonasal sinus surgery. Further improvements incorporating various surgical instruments should broaden its clinical usefulness.     

影像导航下鼻内镜手术58例临床分析

目的　探讨影像导航技术在鼻内镜手术中应用的有关问题。方法　回顾性分析 5 8例患者 ,其中慢性鼻窦炎、鼻息肉 39例、孤立性蝶窦炎 6例、坏死性上颌窦炎 3例、蝶窦囊肿 5例、鼻咽纤维血管瘤 2例 ;鼻颅沟通性脑膜瘤、外伤性脑脊液鼻漏、外伤性视神经损伤各 1例。所有病例均采用BrainLab影像导航系统及鼻内镜实施手术。结果　影像导航术前准备时间 (包括配准、头架定位、常规器械注册等 ) 10～ 2 0min ,平均 15min。 5 2例手术区域影像标志与实体解剖标志间的误差≤ 1 5mm ,6例 >3mm。影像导航可准确定位视神经等解剖标志 ,无手术并发症发生。结论　影像导航系统与内镜相驳接 ,不仅可以帮助术者在术中定位鼻腔、鼻窦、颅底的解剖结构 ,并可使手术视野扩展到内镜之外 ,使术者在术野中进行手术操作的同时 ,能顾及到术野周围的重要结构。特别是在复杂的手术中 ,可提高手术的精确性和安全性     

Increase of accuracy in intraoperative navigation through high-resolution flat-panel volume computed tomography: experimental comparison with multislice computed tomography-based navigation.

HYPOTHESIS: High-resolution imaging, as provided by flat-panel-based volume computed tomography (fpVCT), could increase navigation accuracy and could therefore improve image-guided procedures or make novel navigated surgery concepts possible. BACKGROUND: Intraoperative navigation is an accepted tool in head and neck surgery. However, its use is limited in the lateral cranial base because of its low surgical accuracy. Surgical accuracy is substantially influenced by the resolution of the underlying data set. The fpVCT offers a resolution of nearly two times higher than multislice computed tomography (MSCT). Target registration error (TRE), as a measurement for surgical navigation accuracy, should decrease when navigation is based on fpVCT data sets. METHODS: An acrylic glass phantom with 37 fiducial points was scanned in a current MSCT and in an experimental fpVCT. Both data sets were imported in an optical navigation system. Five fiducial points were used for registration, and seven points were used for measuring TRE. The distance between the indicated pointer tip and the corresponding fiducial point in data set was measured as TRE. Registration and TRE measurement were repeated five times for each computed tomographic data set. Average TREs were calculated, and results were compared using t-test. RESULTS: The average TRE using MSCT (0.82 mm [standard deviation, 0.35 mm]) was significantly higher than that using fpVCT (0.46 mm [standard deviation, 0.22 mm]) (p < 0.01). CONCLUSION: Submillimeter surgical navigation accuracy is possible using high-resolution fpVCT. This could be highly beneficial in cranial base surgery navigation.     

Sonographisch unterstützte computerassistierte Chirurgie (SACAS) in der Orbitachirurgie

Background

The application of computer assisted procedures in orbital surgery is made more difficult by the intraoperative tissue shift in intraorbital structures, since this intraoperative dislocation cannot be imaged in preoperative CT/MR datasets.

Methods

After preoperative recording of CT and/or MR datasets in five patients with orbita affected by frontobasal tumors, we used intraoperative sonography by coupling the ultrasound unit to the navigation system.

Results

Registration, referencing and calibration of the ultrasound system proceeded without any difficulties. Intraoperatively, the structures of the anterior and middle thirds of the orbita and their tissue shift could be particularly well evaluated sonographically.

Conclusion

The use of navigated sonography enables repeated intraoperative re-evaluation of preoperative CT/MR datasets. The fusion of intraoperative sonography with preoperative imaging visualizes the tissue shift and facilitates the identification of anatomical structures and the spatial orientation of the surgeon. This appears to allow both increased operative radicality and greater tissue protection. In our opinion, the intraoperative parallel application of a non-calibrated ultrasound system and an only CT/MRT based navigation system cannot fulfill these requirements because of anatomical complexity.     

Navigation as a quality management tool in cochlear implant surgery

This cadaver study assessed the value of navigation in cochlear implant surgery. Cochlear implantation was simulated on a cadaver using a Stryker-Leibinger navigation system and a Nucleus 24 Contour implant. A conventional surgical strategy consisting of mastoidectomy, posterior tympanotomy, and cochleostomy was performed. The navigated surgical procedure was evaluated for accuracy, reliability, reproducibility, and practicability. The technology of computer-assisted surgery is applicable in cochlear implantation and beneficial in as much as the navigation-controlled implantation constitutes a non-invasive instrument of quality management. Nevertheless, in order to keep the point accuracy below one millimeter, a referencing method using concealed bordering anatomical structures may be further needed to perform the cochleostomy reliably under the guidance of a navigation system. More reproducible reference systems are needed if navigated lateral skull base surgery is to be fully relied upon.     

Computerassistierte Chirurgie an der Rhinobasis

The procedure of instrument navigation has been an established one since its introduction in ENT by Schloendorff. It facilitates better intraoperative orientation. The opto-electric and electromagnetic procedures are sophisticated principles of intraoperative position recognition. It can be assumed that up to 30% of all ENT hospitals in Germany have access to navigation systems. These systems are used almost exclusively for functional endoscopic sinus surgery (FESS). The impact of instrument navigation is estimated by surgeons predominantly positively. A navigation system enables a saving of up to 10% in terms of operating time. Extended approaches in the frontal skull base appear to benefit from the use of navigation support to a high degree. However, scientific data are still lacking. The current boundaries of simple instrument navigation in the frontal skull base are set by the attainable accuracy of approx. 2 mm and the relatively simple representation of the information in planar sectional views. Instrument navigation should be used in the frontal skull base as frequently as possible, even in less complex procedures. Only in this way can familiarity with the system be achieved.     

Image-guided endoscopic sinus surgery: a comparison of two navigation systems

We evaluated the effectiveness of two navigation systems with optical tracking in endoscopic sinus surgery (ESS). The Signa SP/i Intraoperative navigation system (General Electric Co., Intraoperative NS) is advantageous in acquiring both real time and high-resolution images during surgery, compared to conventional image-guided navigation (Stealth Station TREON, Medtronic Inc., IGNS) that rely entirely on preoperative three-dimensional images. We studied the following in 14 patients treated with intraoperative NS and 19 treated with IGNS: 1) additional time for navigation system implementation, 2) available instrumentations in ESS, and 3) navigation system accuracy. Navigation systems required additional time to prepare ESS. The time lapse from admittance to the operating room to ESS onset was measured in patients under both systems and controls undergoing ESS without any image guidance. Preparation of the intraoperative NS required an additional 52 min and IGNS required 17 min compared to the control group. Based on operative instruments, the intraoperative NS has some limitations arising from the application of a high magnetic field. Surgical instruments must not be attracted by the magnetic field in the operating room. So those used in our study were thoroughly examined and some remanufactured using MR safe materials. All instruments in ESS could be used in surgical guidance during surgery in the IGNS. Anatomic landmarks were accurately visualized using intraoperative NS and IGNS. Intraoperative NS renews the image during surgery, so surgeons could confirm the surgical outcome during ESS. Since the average distant error in both systems was between 1 mm and 2.5 mm, we confirmed that accuracy obtained with both navigation system was suitable for ESS completion. The intraoperative NS renewed the image during navigation. In conclusion, both navigation systems are sufficient for accurate image navigation in ESS, but navigation systems must be selected based on the individual case.     

Experience with various 3-dimensional navigation systems in head and neck surgery

OBJECTIVE: To evaluate the benefits and difficulties encountered when using various 3-dimensional (3-D) navigation systems in head and neck procedures. DESIGN: Five different navigation systems were used for preoperative planning and intraoperative 3-D navigation in procedures at the paranasal sinuses, the frontal and lateral skull bases, and the petrous bone. INTERVENTION: Intraoperative 3-D localizing systems (position-sensitive mechanical arms, infrared cameras, etc) demand reliable patient fixation on the operating table. We achieved this by developing a noninvasive head holder. Other systems allow patient movements by using magnetic digitizing technology (ARTMA System) and sophisticated programming. RESULT: Having surpassed an initial learning curve, we now achieve an accuracy of 1 to 2 mm regularly. Especially in paranasal and frontal basal surgery, all navigation systems used provide valuable positioning information during surgery. In particular for revision or tumor surgery, decisive benefits resulted from use of these systems: shorter overall operation time; safer manipulation near delicate structures; and reliable identification of the skull base even in patients with bleeding, scarring, or missing anatomical landmarks. CONCLUSIONS: We performed approximately 250 operations with different systems and introduced navigation at the lateral skull base and the petrous bone with mechanical, optic, and magnetic digitizers. In these anatomical areas, navigation was used successfully; the technical challenge is greatest at the lateral skull base, however.     

Impact of a self-developed planning and self-constructed navigation system on skull base surgery: 10 years experience

CONCLUSION: Our self-developed planning and navigation system has proven its capacity for accurate surgery on the anterior and lateral skull base. With the incorporation of augmented reality, image-guided surgery will evolve into 'information-guided surgery'. OBJECTIVE: Microscopic or endoscopic skull base surgery is technically demanding and its outcome has a great impact on a patient's quality of life. The goal of the project was aimed at developing and evaluating enabling navigation surgery tools for simulation, planning, training, education, and performance. This clinically applied technological research was complemented by a series of patients (n=406) who were treated by anterior and lateral skull base procedures between 1997 and 2006. MATERIALS AND METHODS: Optical tracking technology was used for positional sensing of instruments. A newly designed dynamic reference base with specific registration techniques using fine needle pointer or ultrasound enables the surgeon to work with a target error of < 1 mm. An automatic registration assessment method, which provides the user with a color-coded fused representation of CT and MR images, indicates to the surgeon the location and extent of registration (in)accuracy. Integration of a small tracker camera mounted directly on the microscope permits an advantageous ergonomic way of working in the operating room. Additionally, guidance information (augmented reality) from multimodal datasets (CT, MRI, angiography) can be overlaid directly onto the surgical microscope view. The virtual simulator as a training tool in endonasal and otological skull base surgery provides an understanding of the anatomy as well as preoperative practice using real patient data. RESULTS: Using our navigation system, no major complications occurred in spite of the fact that the series included difficult skull base procedures. An improved quality in the surgical outcome was identified compared with our control group without navigation and compared with the literature. The surgical time consumption was reduced and more minimally invasive approaches were possible. According to the participants' questionnaires, the educational effect of the virtual simulator in our residency program received a high ranking.     

Neue Entwicklungen in der computerassistierten Chirurgie

Ever faster processor capacity is having an impact on computer-assisted or computer-aided surgery (CAS). The fusion of different imaging modalities enables functional data such as PET-CT, for example, to be available in image-guided surgery. Referencing of image data is the key to precise navigation. Intraoperative data acquisition is a new approach to improving accuracy. Thus, intraoperative CT conducted under navigational support enables automatic referencing of up-to-date image data. Alternatively, intraoperative magnetic resonance imaging or intraoperative sonography can be performed. Ultrasound systems have already been successfully integrated in existing navigational systems to compensate for intraoperative tissue shifting. Ultrasound systems may play a role in the future as a single modality in image-guided surgery in soft tissue of the neck and skull bone.     

导航系统在鼻眶筛复合骨折术中的应用

目的 探讨导航系统在鼻眶筛复合骨折手术中的应用,寻求导航系统的介入对鼻眶筛复合骨折手术复位精准性的帮助及导航系统手术的优势。 方法 62例鼻眶筛复合骨折的患者被纳入试验中。在采集并导入DICOM格式的CT影像学数据后,术前利用计算机辅助设计复合面部对称性的鼻眶筛复合骨折复位方案,术中在导航系统的指导下完成鼻眶筛复合骨折的复位手术,并实时验证复位后位置与术前设计方案的匹配程度。 结果 在导航系统通过注册后,术中的骨折及解剖位置与CT影像学数据精准吻合,计算机的系统误差控制在1 mm之内。所有的手术都在实时导航下顺利完成,术中根据术前的复位方案精准复位,利用导航系统判断复位后骨质与设计方案的匹配程度。患者术后面部外形改善明显,所有纳入的患者对手术复位结果满意。 结论 在计算机辅助下,通过术前测量、模拟、设计,导航技术有利于提高鼻眶筛复合骨折术中复位的精准性、减少手术风险、降低再次手术的发生率、恢复面部对称性。     

影像导航技术在鼻及颅底和鼻眼相关疾病内镜手术中的应用

目的 对影像导航技术在鼻及颅底和鼻眼相关疾病内镜手术中的实际应用进行评价。 方法 回顾性分析使用影像导航系统的751例实施鼻内镜手术的病例,其中565例应用美敦力Stealth Station^TM红外线导航系统,186例应用美敦力Fusion电磁导航系统。对导航系统的精确性、 术前导航准备时间、 术者对使用导航辅助的价值认知度、 导航手术中发生的不良事件,以及术中、 术后的并发症进行详细记录。 结果 红外线导航应用解剖标志法注册可提供0.5~2.0 mm的定位误差,电磁导航应用轮廓(Tracer)注册法均能达到<1 mm的注册误差。应用VAS评分评价术者对导航辅助的价值认知度为(8.3±1.2)分。其中,额窦、视神经管、颈内动脉管被认为是应用导航辅助价值最大的解剖部位。导航手术中发生的不良事件主要为影像漂移、定位器械无法实时定位、注册失败。全部病例均能顺利手术,无颅内和眶内并发症出现。 结论 影像导航与内镜手术的结合,为术者提供了更精确的解剖指引;能辅助提高内镜手术的准确性,消除内镜下可能出现的解剖错觉,尤其是在处理涉及额窦、视神经、颈内动脉的鼻颅底及眼眶手术中。导航手术中不良事件的发生率较低,此时术者的设备操作经验和内镜手术经验尤为重要。     

Guided surgery in a subtemporal approach in CPA tumors?

BACKGROUND: Computer assisted surgery (CAS) permits the visualization of hidden bony covered structures invisible for the human eye with radiological 3d data sets. The surgeon might be able to orientate anatomically during surgery without having to prepare the according landmarks. This would mean less surgical traumatization and a shorter and smaller operation corridor. METHOD: We determined the use of CAS in a quality assurance analysis with the subtemporal approach in 8 patients with supra-meatal tumors type A of the cerebellopontine angle. Various navigation systems and methods for referencing for the registration of the patients' heads were used. The question was whether it is possible intraoperatively without preparation of known anatomical landmarks to define the borders of an optimal positioned temporary bone cap and to identify the bony covered inner auditory canal and its neuronal structures without orienting neurostimulation. RESULT: It was possible with CAS to assess intraoperatively the borders of a temporary bone cap above the cranially positioned mastoid cell. However, the objective inaccuracy of 2 to 28 mm observed during surgery did not allow a secure identification of the inner auditory canal. CONCLUSIONS: CAS with the subtemporal approach cannot replace the conventional preparation of known anatomical landmarks nor neurostimulation to identify neural structures, due to the expected high inaccuracy with the non-invasive referencing systems that are available today.     

Image-guided transnasal endoscopic surgery of the paranasal sinuses and anterior skull base

Image-guided surgery represents a new technology with applicability to patients undergoing functional endoscopic sinus surgery for medically refractory rhinosinusitis. It also shows promise in helping to safely expand minimally invasive transnasal endoscopic techniques for nonrhinosinusitis diagnoses of the paranasal sinuses, orbits, and anterior skull base. This report discusses the application of the InstaTrak, a commercially available image-guided surgical navigation system, in 109 consecutive operations. The device was useful for localization to within less than 3 mm in 106 (98%) cases. In the remaining three (2%) surgeries where the perceived accuracy was not within 3 mm, the device was not used. The acquisition of radiographic data, operating room set-up, intraoperative localization and complications, and indications for surgical navigation will be discussed.     

Three-dimensional computed tomography angiography of the internal carotid artery for preoperative evaluation of sinonasal lesions and intraoperative surgical navigation

INTRODUCTION: Three-dimensional computed tomographic angiography (3DCTA) demonstrates the spatial relationships of the internal carotid artery (ICA) and adjacent skull base. This imaging modality may be incorporated into intraoperative surgical navigation during endoscopic skull base surgery. METHODS: The charts of patients who had undergone 3DCTA imaging between July 2002 and February 2005 were reviewed. For 3DCTA, 1 mm axial computed tomography (CT) scan images were obtained with simultaneous intravenous contrast bolus on a multidetector CT scanner (Somatom Sensation 16, Siemens, Munich, Germany). The CBYON Suite version 2.6 to 2.8 (Med-Surgical Services, Mountain View, CA) was also used for creating CTA images through its volume-rendering protocols. RESULTS: A total of 22 3DCTA studies were performed for diagnostic evaluation or preoperative planning. In 18 instances, the 3DCTA images were used during intraoperative surgical navigation. The specific indications for obtaining the 3DCTA study included neoplasm (11 cases), cerebrospinal fluid leak (3 cases), fibro-osseous lesion (2 cases), mucocele (2 cases), and other (4 cases). Images generated by 3DCTA facilitated the definition of the anatomic relationships between the ICA and skull base lesion. During intraoperative surgical navigation, the 3DCTA provided critical information about the ICA location and adjacent skull base anatomy in the operative field. CONCLUSIONS: 3DCTA is a useful means for assessing the ICA and its relationship to skull base lesions. Incorporation of 3DCTA into intraoperative surgical navigation facilitates the comprehension of operative field anatomy in the ICA region. As a result, this imaging technique, especially when combined with intraoperative surgical navigation, may extend the applications of minimally invasive endoscopic approaches to the skull base.