Search

Open craniotomy remains the main stay of diagnostic and therapeutic management of brain tumor. Intraoperative localization may be difficult due to the fact that some lesions, which might appear clearly on MR or CT, could be completely indistinguishable from normal brain when examined through a microscope, hence the use of the stereotactic head frame. The disadvantages of this technique are the patient’s discomfort, inconvenience of travelling between OT and imaging department with head ring on, the difficulty in calculating the co-ordinates and the fact that introduction of Biopsy needle remains a blind procedure. At the 1991 American Association of Neurological Surgeons annual meeting, a new surgical navigational method initially called Frameless Stereotaxy (interactive image-guided surgery) came into being. Intraoperative Localization Device (ILD) include linked and unlinked devices. Linked devices include stereotactic frames, active robotic arms (PUMA Industrial Robot, the Zeiss MKM microscope) and passive localization arms (the OAS system) and intraoperative tomographic scanners. A number of steps are taken in order to ensure correct functioning of these systems. • Patient selection • Fiducial placement • Imaging • Data transport • Presurgical viewing • Identification and registration of markers • Surgical planning and intraoperative navigation We are using Operating Arm System (OTS) designed by Radionics, Inc. for cases that require precise localization and Intraoperative guidance. OTS consists of a workstation connected to a probe with optical digitisers, which interacts with a camera which tracks, the movement of the probe in 3 dimension. We use four stick-ons to calibrate the system and two other as target points. The author’s personal experience has been with 70 cases over the last six years, which shall be presented.

X-ray based imaging is routinely used for preoperative diagnosis and planning, for intraoperative guidance and control, and for the postoperative evaluation of computer-assisted surgery (CAS) in the majority of its applications. Standard radiography, fluoroscopy and computed tomography (CT) are the modalities of outstanding importance. In this report we will review the state of the art in fluoroscopy and in CT with respect to technology and physics, but -- except for detector technology -- we will neglect standard radiography. Recent technical developments which aim at providing CT capabilities for standard fluoroscopy equipment are of particular topical importance; they can significantly improve workflow in the operating room (OR). Considerations regarding x-ray doses are of high concern. Our analysis indicates that most types of applications, including CT, do not bear considerable risks. However, fluoroscopic interventions with long exposure times have to be carefully monitored.

Tissue diagnostic techniques based on optical spectroscopy, in various incarnations, are approaching clinical reality for intraoperative guidance of surgical procedures. Examination of tissue properties by elastic light-scattering spectroscopy may constitute a preferable alternative to frozen-section pathology or touch imprint cytology for intraoperative assessment of resection margins during breast-conserving surgery. Clin Cancer Res; 18(22); 6083–5. ©2012 AACR.

In this paper we present results showing that Graphic Processing Units (GPUs) can be used to accelerate the simulation of the thermal field dose during Radio Frequency Ablation (RFA). Specifically we show that this simulation can be conducted in real-time, allowing the development of intraopera- tive guidance platforms that track and display the thermal lesion as it forms during the intervention. Real time simulation has not been reported before, and has been a critical factor preventing development of intraoperative guidance tools. I. INTRODUCTION

Surgery refers to the act of cutting the tissue of a patient for the purpose of treating or diagnosis. The goal is to improve the patient’s condition, either by learning more about the disease, or by surgically remedying it. However, there is a significant risk of doing the opposite.

This paper introduces a structured light based imaging architecture able to serve for the development of an affordable guided fracture reduction system. The 3D models of the bones in the healthy limb are used for the preoperative alignment of the proximal and distal segments of the fractured bone using algorithm for automated registration. A structured light setup performs the reconstruction of 3D information needed for the intraoperative guidance in order to support the fracture reduction in accord with the preoperative alignment.

With regard to patient selection for PNL, planning of percutaneous access, intraoperative guidance and postoperative evaluation of potential complications and stone-free status, imaging plays a crucial role. In this chapter the role of current imaging modalities is discussed, and focus is made on how appropriate imaging studies may lead to safe and efficacious percutaneous renal surgery. The role of the various preoperative, intraoperative and postoperative imaging tools is discussed. Furthermore, possible future scenarios with regard to imaging in PNL are briefl y touched.

Recently, there has been a burgeoning interest in the use of image-guided navigation to improve the safety and effectiveness of neurosurgical procedures. The intraoperative use of magnetic resonance imaging (MRI) provides the most accurate guidance available. This report discusses the hardware and software improvements that have made intraoperative MRI a reality and describes the use of this technology for neurosurgical intraoperative guidance.

Thus far, endoscopes are still mainly used as a keyhole to look inside the human body. Of course, endoscopes can be integrated into standard navigation systems, allowing to fuse the acquired images with other imaging modalities or 3-dimensional models derived from them. Such approaches usually rely on tracking external markers, allowing the visualization of the endoscopic probe in coordinate systems, which can be fixed either to the patient on the operating table or to some preoperatively acquired images. This technology has been used both with rigid endoscopes like in ventriculostomy and, when relying on magnetic tracking methods requiring no direct visibility of the markers, also with flexible devices like in image registered gastroscopic ultrasound procedures. Nevertheless, existing endoscopes can be enhanced by appropriate computer vision tools to a full imaging device allowing taking quantitative measurements and can therefore be used even standalone in an image-guided interventional systems, without incorporating any other imaging modalities. In this chapter, we concentrate on the corresponding approaches and describe the main technological components of such Quantitative endoscopy systems, while also illustrating their value as intraoperative imaging device by some prototypical applications.

Image-guided intervention in gynecologic oncology includes biopsy, aspiration and drainage, transcatheter treatment, and intraoperative guidance for surgical procedures. This chapter focuses on needle biopsy and aspiration, using ultrasound and CT guidance.

Recent technological advances in surgery have resulted in the development of a range of new techniques that have reduced patient trauma, shortened hospitalization, and improved diagnostic accuracy and therapeutic outcome. Despite the many appreciated benefits of minimally invasive surgery (MIS) compared to traditional approaches, there are still significant drawbacks associated with conventional MIS including poor instrument control and ergonomics caused by rigid instrumentation and its associated fulcrum effect. The use of robot assistance has helped to realize the full potential of MIS with improved consistency, safety and accuracy. The development of articulated, precision tools to enhance the surgeon's dexterity has evolved in parallel with advances in imaging and human-robot interaction. This has improved hand-eye coordination and manual precision down to micron scales, with the capability of navigating through complex anatomical pathways. In this review paper, clinical requirements and technical challenges related to the design of robotic platforms for flexible access surgery are discussed. Allied technical approaches and engineering challenges related to instrument design, intraoperative guidance, and intelligent human-robot interaction are reviewed. We also highlight emerging designs and research opportunities in the field by assessing the current limitations and open technical challenges for the wider clinical uptake of robotic platforms in MIS.

Using a custom-made antibody to target the overexpression of epithelial adhesion molecule (EpCAM), a far-red fluorescent gene reporter, a solid phantom, and a military grade intensified image intensifier, we quantified the performance of near-infrared fluorescence imaging for intraoperative margin detection.

With the evolution of imaging technologies and tracers, the applications for nuclear molecular imaging are growing rapidly. For example, nuclear medicine is increasingly being used to guide surgical resections in complex anatomical locations. Here, a future workflow is envisioned that uses a combination of pre-operative diagnostics, navigation and intraoperative guidance. Radioguidance can provide means for pre-operative and intraoperative identification of “hot” lesions, forming the basis of a virtual data set that can be used for navigation. Luminescence guidance has shown great potential in the intraoperative setting by providing optical feedback, in some cases even in real time. Both of these techniques have distinct drawbacks, which include inaccuracy in areas that contain a background signal (radioactivity) or a limited degree of signal penetration (luminescence). We, and others, have reasoned that hybrid/multimodal approaches that integrate the use of these complementary modalities may help overcome their individual weaknesses. Ultimately, this will lead to advancement of the field of interventional molecular imaging/image-guided surgery. In this review, an overview of clinically applied hybrid surgical guidance technologies is given, whereby the focus is placed on tracers and hardware.

OBJECTIVE Navigated 3D ultrasound is a novel intraoperative imaging adjunct permitting quick real-time updates to facilitate tumor resection. Image quality continues to improve and is currently sufficient to allow use of navigated ultrasound (NUS) as a stand-alone modality for intraoperative guidance without the need for preoperative MRI. METHODS The authors retrospectively analyzed cases involving operations performed at their institution in which a 3D ultrasound navigation system was used for control of resection of brain tumors in a “direct” 3D ultrasound mode, without preoperative MRI guidance. The usefulness of the ultrasound and its correlation with postoperative imaging were evaluated. RESULTS Ultrasound was used for resection control in 81 cases. In 53 of these 81 cases, at least 1 intermediate scan (range 1–3 intermediate scans) was obtained during the course of the resection, and in 50 of these 53 cases, the result prompted further resection. In the remaining 28 cases, intermediate scans were not performed either because the first ultrasound scan performed after resection was interpreted as showing no residual tumor (n = 18) and resection was terminated or because the surgeon intentionally terminated the resection prematurely due to the infiltrative nature of the tumor and extension of disease into eloquent areas (n = 10) and the final ultrasound scan was interpreted as showing residual disease. In an additional 20 cases, ultrasound navigation was used primarily for localization and not for resection control, making the total number of NUS cases where radical resection was planned 101. Gross-total resection (GTR) was planned in 68 of these 101 cases and cytoreduction in 33. Ultrasound-defined GTR was achieved in 51 (75%) of the cases in which GTR was planned. In the remaining 17, further resection had to be terminated (despite evidence of residual tumor on ultrasound) because of diffuse infiltration or proximity to eloquent areas. Of the 33 cases planned for cytoreduction, NUS guidance facilitated ultrasound-defined GTR in 4 cases. Overall, ultrasound-defined GTR was achieved in 50% of cases (55 of 111). Based on the postoperative imaging (MRI in most cases), GTR was achieved in 58 cases (53%). Final (postresection) ultrasonography was documented in 78 cases. The findings were compared with the postoperative imaging to ascertain concordance in detecting residual tumor. Overall concordance was seen in 64 cases (82.5%), positive concordance was seen in 33 (42.5%), and negative in 31 (40%). Discordance was seen in 14 cases—with ultrasound yielding false-positive results in 7 cases and false-negative results in 7 cases. Postoperative neurological worsening occurred in 15 cases (13.5%), and in most of these cases, it was reversible by the time of discharge. CONCLUSIONS The results of this study demonstrate that 3D ultrasound can be effectively used as a stand-alone navigation modality during the resection of brain tumors. The ability to provide repeated, high-quality intraoperative updates is useful for guiding resection. Attention to image acquisition technique and experience can significantly increase the quality of images, thereby improving the overall utility of this modality.

We incorporate for the first time optical coherence elastography (OCE) into a needle probe and demonstrate its ability to provide depth-resolved information about the mechanical properties of soft tissues. This allows analysis of tissues located much deeper than has previously been possible with other forms of OCE. OCE exploits the microscopic resolution of optical coherence tomography (OCT) to produce high-resolution maps of tissue mechanical properties. While OCE has potential to delineate diseased and healthy tissues (e.g., stiff tumor in soft tissue), standard techniques are limited by the penetration depth of OCT in tissue (2-3 mm). Our OCE needle probe overcomes this limitation, as it may be inserted deep within the body to perform measurements. We tested needle-based OCE in tissue-mimicking phantoms and ex vivo porcine airway tissue comprising layers of varying stiffness. Results demonstrate mechanical differentiation of tissues and identification of tissue interfaces. The proof-of-principle results presented here pave the way for future measurements in human breast tissue that will aim to establish needle-based OCE as a viable technique for intraoperative guidance of breast cancer surgery.

Objective To describe the evolution and current applications of intraoperative parathyroid hormone (PTH) monitoring along with a detailed description of intraoperative protocol and assay methodology. Methods Review of the literature regarding the role of intraoperative PTH monitoring in parathyroidectomy, controversies associated with its use in the treatment of hyperparathyroidism, and outcomes using this operative approach. The technologies currently available for “quick” PTH measurement are summarized. Results Since its inception, intraoperative PTH monitoring has become an essential tool in the endocrine surgeon’s armamentarium for treatment of sporadic primary hyperparathyroidism. Intraoperative PTH monitoring changed the operative approach to this disease from bilateral neck exploration with identification of all parathyroid glands and excision based on size, to a highly successful procedure achieved with a limited dissection and gland excision guided by hormone hypersecretion instead of morphologic characteristics. Intraoperative PTH monitoring accuracy is directly associated with the intraoperative criteria used. Although controversy exists regarding the best intraoperative PTH monitoring criteria to be used, most specialized centers have shown excellent results with this intraoperative guidance. Currently, most parathyroid surgeons use intraoperative PTH monitoring, selectively or routinely, during parathyroidectomy. Conclusion Parathyroidectomy guided by intraoperative PTH monitoring to treat sporadic primary hyperparathyroidism is a highly successful and less-invasive approach associated with lower risks than bilateral neck exploration, and it has become the surgical treatment of choice for this disease. (Endocr Pract. 2011;17[Suppl 1]:44-53)

We have developed a handheld fiberoptic probe for tissue fluorescence quantification and a technique to produce depth-resolved maps of sub-surface tumor fluorescence, to elaborate upon intraoperative fluorescence guided resection of brain tumor.

Intraoperative monitoring of brainstem auditory evoked potential (BAEP) was done in 34 patients submitted to microvascular decompression (MVD). Seventeen of these patients had trigeminal neuralgia, and 17 had hemifacial spasm. Transitory postoperative hearing loss was observed in 6 (18%) of the patients, and permanent hearing loss was observed in 2 (6%) of the patients. Wave I-V interpeak latency (IPL) was calculated during each step of the MVD procedure in order to identify the dangerous steps of the surgery. Wave I-V IPL abnormalities occurred more frequently during cerebellar retraction. Of the 6 patients who had total loss of BAEP lasting throughout the surgery, 1 (17%) had definitive deafness. Ten of the 34 patients had an absence or partial diminution of BAEP without total normalization before the end of surgery. Among these 10 patients, 2 had transitory hearing loss and 1 had permanent hearing loss.

In 15 patients who were to undergo resection of hepatic metastases, three-dimensional (3D) images of the liver were rendered from axial T2-weighted MR images by a dedicated 3D workstation. This report assesses the utility of these images in preoperative planning and intraoperative guidance. In three patients, the preoperative 3D images convinced the surgeon of resectability. All patients had laparotomies and in 12 patients, in whom the liver lesions were evaluated, there was good to excellent spatial correlation. Intraoperatively, the 3D images aided the surgeon by allowing early detection of unresectability, by showing relationships of lesions to major vessels, and by directing the surgeon to lesions otherwise difficult to find. In two patients, the original MR images failed to show multiple small lesions, thus limiting the usefulness of the 3D images.

The long term objective of our research is to develop a system that will automate as much as possible DBS implantation procedures. It is estimated that about 180,000 patients/year would benefit from DBS implantation. Yet, only 3000 procedures are performed annually. This is so because the combined expertise required to perform the procedure successfully is only available at a limited number of sites. Our goal is to transform this procedure into a procedure that can be performed by a general neurosurgeon at a community hospital. In this work we report on our current progress toward developing a system for the computer-assisted pre-operative selection of target points and for the intra-operative adjustment of these points. The system consists of a deformable atlas of optimal target points that can be used to select automatically the pre-operative target, of an electrophysiological atlas, and of an intra-operative interface. The atlas is deformed using a rigid then a non-rigid registration algorithm developed at our institution. Results we have obtained show that automatic prediction of target points is an achievable goal. Our results also indicate that electrophysiological information can be used to resolve structures not visible in anatomic images, thus improving both pre-operative and intra-operative guidance. Our intra-operative system has reached the stage of a working prototype that is clinically used at our institution.

Background Intraoperative intact parathyroid hormone (iPTH) monitoring is useful in the operative management of hyperparathyroidism. Recent studies suggest that measurement of intraoperative total serum calcium (TSC) levels may be a more cost effective and readily available method of intraoperative guidance during neck dissection than iPTH levels, the gold standard. We compared the accuracy of intraoperative TSC to iPTH in predicting surgical cure during parathyroidectomy. Patients and methods From September 1, 2001 to October 31, 2002, 88 parathyroidectomies were performed. iPTH and TSC were measured at the start of the operation, and at 5 and 10 min after gland removal. Data were compared, and trends were analyzed with respect to removal of abnormal parathyroid tissue as confirmed by pathology. One-way analysis of variance was used to determine if decreases in TSC were significant. Results The mean baseline iPTH level (418 ± 610 pg/ml) dropped by 70% 5 min after removal of the abnormal glands (86 ± 102 pg/ml) and by 85% at 10 min (39 ± 39 pg/ml). The mean baseline TSC level (10.0 ± 0.8 mg/dl) dropped by 4% at 5 min after removal of the abnormal glands (9.6 ± 0.9 mg/dl) and remained at 4% at 10 min (9.6 ± 0.8 mg/dl). iPTH dropped by ≥50% in 73 patients (83%) at 5 min and in 87 patients (99%) at 10 min after gland resection. TSC decreased below baseline at 5 min and remained below baseline at 10 min in only 47 patients (54%). In the remaining patients, intraoperative TSC changes were less predictable and did not respond consistently to resection of abnormal glands. Conclusion The decreases in TSC during parathyroidectomy, if present, are minimal. Unlike iPTH levels, TSC levels do not consistently decrease at 5 and 10 min after gland resection. While attractive in terms of cost and availability, intraoperative TSC levels are not clinically reliable in confirming removal of abnormal parathyroid tissue.

A method for accurate intraoperative guidance of a surgical laser beam in neurosurgery is discussed. This method uses intraoperative ultrasound imaging and computer processing to control the movement of the laser. The method is described and images are shown. The system has been tested using data from intraoperative ultrasound imaging of cerebral tumors and simulated tumors of various shapes. >

METHODS: Pilot study including 7 subjects undergoing thyroidectomy for papillary thyroid cancer (PTC) diagnosed by fine-needle-aspiration biopsy between August 2012-June 2013. Immediately after removal of the thyroid gland, measurements using light reflectance spectroscopy (LRS) and auto-fluorescence lifetime measurement (AFLM) were taken from the known cancer lesions and compared to those taken in identical fashion from normal thyroid tissue within the same gland. Sites of measurements were identified by the study pathologist and later vetted against the final pathologic diagnosis to ensure they represented the appropriate tissues. The data were compiled and analyzed using SAS repeated measures mixed model (p < 0.05 significant).

A mathematical model for studying the passive kinematics of total knee prostheses can be useful in computer-aided planning and guidance of total joint replacement. If the insertion location and neutral length of knee ligaments is known, the passive kinematics of the knee can be calculated by minimizing the strain energy stored in the ligaments at any angular configuration of the knee. Insertions may be found intraoperatively, or may come from preoperative 3D medical images. The model considered here takes into consideration the geometry of the prosthesis and patient-specific information. This model can be used to study the kinematics of the knee joint of a patient after total joint replacement. The model may be useful in preoperative planning, computer-aided intraoperative guidance, and the design of new prosthetic joints.

A new multifunctional articulated instrument holder for use in minimally invasive navigated neurosurgery is presented. The instrument holder is secured to the Mayfield clamp, yielding permanent fixation and guidance of instruments. Thus, surgical conditions with the advantages of both conventional and frameless stereotaxic neurosurgery are created without sacrificing the relevant advantages of both methods. Accuracy testing of the instrument holder in combination with the neuronavigation system EasyGuide Neuro demonstrated an error of 0.0 to 2.4 (mean 1.6) mm. In clinical testing, the device has been used for guided catheter insertions, pointer fixation for continuous intraoperative guidance and trajectory planning, navigated endoscopic procedures, and navigated intracerebral biopsies in totally 53 patients.

Recent technological developments in neuroimaging and surgical techniques, including the use of interactive image-guided surgical procedures, have opened new frontiers in neurosurgery. Advances in imaging techniques have created the need for more precise navigational assistance, in order to approach image-defined lesions. Several methods that transform coordinates from imaging studies to the surgical field have been developed and used in intraoperative guidance systems.

The indeterminate pulmonary nodule: improved diagnosis and therapy with thoracoscopic resection. Since 1990, thoracoscopic resections (or video-assisted thoracic surgery — VATS) were performed for 255 pulmonary nodules on 193 patients, 33 of which had undergone preoperative CT-guided needle localization for intraoperative guidance. All thoracoscopic resections were well tolerated with minor operative morbidity and improved postoperative pain and shoulder mobility, and all pulmonary nodules were successfully identified by TR with a conversion rate to open thoracotomy of 6%. TR is an accurate and reliable diagnostic means for pulmonary nodules not amenable to less invasive diagnostic techniques, and has therapeutic potential for primary lung cancer in cases of limited pulmonary reserve.

This issue of Neurosurgical Focus comes at an exciting and perhaps transformational time for those neuroscientists and clinicians involved in the study and treatment of complex cerebrovascular disease. Our diagnostic and therapeutic practices have seen dramatic advances. Imaging capabilities, both anatomical and functional, have improved at a dramatic rate and include neuronavigation modalities for intraoperative guidance, the application of new MR imaging sequences to cerebrovascular disease, and fluorescence angiography to aid in intraoperative decision making.

Radioimmunodetection (RAID) using Tc-99m labeled Fab' fragments of the anti-CEA monoclonal antibody IMMU-4 was performed in a 68-year-old man for preoperative evaluation of colonic metastases. Planar images at 3 and 18 hours showed uptake within known metastases in the left lobe of the liver that had been observed with CT and at surgery during the preceding month. SPECT images at 3 hours demonstrated two additional unsuspected lesions. All sites were surgically confirmed the following day using intraoperative sonographic guidance, with the smallest occult lesion measuring only 6 x 9 mm. This case illustrates the limitations of CT and surgery, the potential of RAID for the detection of occult metastases, the increased sensitivity of SPECT over planar images for detecting lesions less than 1 cm in diameter, and the value of intraoperative guidance for small nonpalpable lesions.

Introduction Epileptogenic lesions and their margins are often difficult to define intraoperatively. Optical spectroscopy, especially diffuse reflectance and fluorescence spectroscopy, can characterize tissue in vivo. We hypothesize that optical spectroscopy can detect unique pathophysiological features of epileptogenic lesions and hence differentiate them from normal brain. This hypothesis was tested by comparing the in vivo optical and fluorescence characteristics of epileptogenic brain lesions (non-neoplastic) with those of normal brain. Methods Patients were recruited from those undergoing evaluation for surgical management of intractable epilepsy at Miami Children's Hospital. Fluoroscence and diffuse reflectance spectra were acquired from the brain using a fiberoptic spectroscopic system. Both static and dynamic spectral acquisition was performed; thus, the average and time dependent characteristics were assessed. Both hemo-dynamic and metabolic physiologic characteristics were retrieved from the spe...

Transrectal sonography was used for intraoperative guidance in intrauterine tandem placement for intracavitary radiation therapy and in dilation and curettage procedures. The authors describe the method and three representative cases in which it was applied. It is concluded that the technique may prevent complications such as uterine perforation or bladder injury in tandem placement, and that it can facilitate dilation and curettage in complicated cases.

✓ The authors present a simple and accurate new technique for preoperative localization of convexity lesions of the brain by means of magnetic resonance (MR) imaging. This method uses measurements from the initial diagnostic MR image and provides precise intraoperative guidance to cortical and subcortical cerebral lesions.