Image-Guided Navigation in Spine Surgery: From Historical Developments to Future Perspectives

Intraoperative navigation is critical during spine surgery to ensure accurate instrumentation placement. From the early era of fluoroscopy to the current advancement in robotics, spinal navigation has continued to evolve. By understanding the variations in system protocols and their respective usage in the operating room, the surgeon can use and maximize the potential of various image guidance options more effectively. At the same time, maintaining navigation accuracy throughout the procedure is of the utmost importance, which can be confirmed intraoperatively by using an internal fiducial marker, as demonstrated herein. This technology can reduce the need for revision surgeries, minimize postoperative complications, and enhance the overall efficiency of operating rooms.

Interventional Oncology: 2024 Update

Interventional Oncology (IO) stands at the forefront of transformative cancer care, leveraging advanced imaging technologies and innovative interventions. This narrative review explores recent developments within IO, highlighting its potential impact facilitated by artificial intelligence (AI), personalized medicine and imaging innovations. The integration of AI in IO holds promise for accelerating tumour detection and characterization, guiding treatment strategies and refining predictive models. Imaging modalities, including functional MRI, PET and cone beam CT are reshaping imaging and precision. Navigation, fusion imaging, augmented reality and robotics have the potential to revolutionize procedural guidance and offer unparalleled accuracy. New developments are observed in embolization and ablative therapies. The pivotal role of genomics in treatment planning, targeted therapies and biomarkers for treatment response prediction underscore the personalization of IO. Quality of life assessment, minimizing side effects and long-term survivorship care emphasize patient-centred outcomes after IO treatment. The evolving landscape of IO training programs, simulation technologies and workforce competence ensures the field's adaptability. Despite barriers to adoption, synergy between interventional radiologists' proficiency and technological advancements hold promise in cancer care.

Advances in Virtual Cutting Guide and Stereotactic Navigation for Complex Tumor Resections of the Sacrum and Pelvis: Case Series with Short-Term Follow-Up

Primary malignancies of the sacrum and pelvis are aggressive in nature, and achieving negative margins is essential for preventing recurrence and improving survival after en bloc resections. However, these are particularly challenging interventions due to the complex anatomy and proximity to vital structures. Using virtual cutting guides to perform navigated osteotomies may be a reliable method for safely obtaining negative margins in complex tumor resections of the sacrum and pelvis. This study details the technique and presents short-term outcomes. Patients who underwent an en bloc tumor resection of the sacrum and/or pelvis using virtual cutting guides with a minimum follow-up of two years were retrospectively analyzed and included in this study. Preoperative computer-assisted design (CAD) was used to design osteotomies in each case. Segmentation, delineating the tumor from normal tissue, was performed by the senior author using preoperative CT scans and MRI. Working with a team of biomedical engineers, virtual surgical planning was performed to create osteotomy lines on the preoperative CT and overlaid onto the intraoperative CT. The pre-planned osteotomy lines were visualized as "virtual cutting guides" providing real-time stereotactic navigation. A precision ultrasound-powered cutting tool was then integrated into the navigation system and used to perform the osteotomies in each case. Six patients (mean age 52.2 ± 17.7 years, 2 males, 4 females) were included in this study. Negative margins were achieved in all patients with no intraoperative complications. Mean follow-up was 38.0 ± 6.5 months (range, 24.8-42.2). Mean operative time was 1229 min (range, 522-2063). Mean length of stay (LOS) was 18.7 ± 14.5 days. There were no cases of 30-day readmissions, 30-day reoperations, or 2-year mortality. One patient was complicated by flap necrosis, which was successfully treated with irrigation and debridement and primary closure. One patient had local tumor recurrence at final follow-up and two patients are currently undergoing treatment for metastatic disease. Using virtual cutting guides to perform navigated osteotomies is a safe technique that can facilitate complex tumor resections of the sacrum and pelvis.

A Case of U-shaped Sacral Fracture After Longstanding Spinopelvic Fixation Treated With Percutaneous Sacroiliac Joint Fusion and Iliosacral Osteosynthesis

Sacral fractures are pelvic ring injuries that usually occur following a fall from height and may present with neurological injury. They are divided into several subtypes based on the pattern and location of injury. Certain subtypes require operative management due to the risk of neural compromise and inadequate axial load transfer, limiting mobility. Spinopelvic fixation has been reported as an efficient surgical treatment to restore the stability of U-shaped sacral fractures and to accelerate healing by relieving sacral stress. It is unclear if low-velocity sacral fractures occurring after longstanding lumbosacral fusion with pelvic fixation require additional surgical intervention. An elderly female with osteoporosis and prior T4-pelvis instrumented fusion sustained a fragility sacral fracture and was treated conservatively. At follow-up, she developed a symptomatic U-shaped sacral fracture. The increased fracture displacement and nonunion were chiefly attributed to sacroiliac joint hypermobility. A percutaneous osteosynthesis at the S1 and S2 levels was performed with a novel type of implant to achieve concomitant sacroiliac joint stabilization and fusion. Implants were placed with the help of intraoperative three-dimensional imaging and image-guided navigation to avoid the previously installed pelvic hardware. In summary, U-shaped fractures can develop nonunion despite pre-existing spinopelvic fixation and can be treated adequately with percutaneous iliosacral osteosynthesis. A sacroiliac joint fixation and fusion should be considered in the same setting as sacroiliac joint instability may contribute to or exacerbate nonunion.

Review of Enhanced Handheld Surgical Drills

The handheld drill has been used as a conventional surgical tool for centuries. Alongside the recent successes of surgical robots, the development of new and enhanced medical drills has improved surgeon ability without requiring the high cost and consuming setup times that plague medical robot systems. This work provides an overview of enhanced handheld surgical drill research focusing on systems that include some form of image guidance and do not require additional hardware that physically supports or guides drilling. Drilling is reviewed by main contribution divided into audio-, visual-, or hardware-enhanced drills. A vision for future work to enhance handheld drilling systems is also discussed.

Modeling of Respiratory Motion to Support the Minimally Invasive Destruction of Liver Tumors

OBJECTIVE

Respiratory movements are a significant factor that may hinder the use of image navigation systems during minimally invasive procedures used to destroy focal lesions in the liver. This article aims to present a method of estimating the displacement of the target point due to respiratory movements during the procedure, working in real time.

METHOD

The real-time method using skin markers and non-rigid registration algorithms has been implemented and tested for various classes of transformation. The method was validated using clinical data from 21 patients diagnosed with liver tumors. For each patient, each marker was treated as a target and the remaining markers as target position predictors, resulting in 162 configurations and 1095 respiratory cycles analyzed. In addition, the possibility of estimating the respiratory phase signal directly from intraoperative US images and the possibility of synchronization with the 4D CT respiratory sequence are also presented, based on ten patients.

RESULTS

The median value of the target registration error (TRE) was 3.47 for the non-rigid registration method using the combination of rigid transformation and elastic body spline curves, and an adaptation of the assessing quality using image registration circuits (AQUIRC) method. The average maximum distance was 3.4 (minimum: 1.6, maximum 6.8) mm.

CONCLUSIONS

The proposed method obtained promising real-time TRE values. It also allowed for the estimation of the TRE at a given geometric margin level to determine the estimated target position. Directions for further quantitative research and the practical possibility of combining both methods are also presented.

Measuring Respiratory Motion for Supporting the Minimally Invasive Destruction of Liver Tumors

OBJECTIVE

Destroying liver tumors is a challenge for contemporary interventional radiology. The aim of this work is to compare different techniques used for the measurement of respiratory motion, as this is the main hurdle to the effective implementation of this therapy.

METHODS

Laparoscopic stereoscopic reconstruction of point displacements on the surface of the liver, observation of breathing using external markers placed on the surface of the abdominal cavity, and methods for registration of the surface of the abdominal cavity during breathing were implemented and evaluated.

RESULTS

The following accuracies were obtained: above 4 mm and 0.5 mm, and below 8 mm for laparoscopic, skin markers, and skin surface registration methods, respectively.

CONCLUSIONS

The clinical techniques and accompanying imaging modalities employed to destroy liver tumors, as well as the advantages and limitations of the proposed methods, are presented. Further directions for their development are also indicated.

The Accuracy of Patient-Specific Spinal Drill Guides Is Non-Inferior to Computer-Assisted Surgery: The Results of a Split-Spine Randomized Controlled Trial

In recent years, patient-specific spinal drill guides (3DPGs) have gained widespread popularity. Several studies have shown that the accuracy of screw insertion with these guides is superior to that obtained using the freehand insertion technique, but there are no studies that make a comparison with computer-assisted surgery (CAS). The aim of this study was to determine whether the accuracy of insertion of spinal screws using 3DPGs is non-inferior to insertion via CAS. A randomized controlled split-spine study was performed in which 3DPG and CAS were randomly assigned to the left or right sides of the spines of patients undergoing fixation surgery. The 3D measured accuracy of screw insertion was the primary study outcome parameter. Sixty screws inserted in 10 patients who completed the study protocol were used for the non-inferiority analysis. The non-inferiority of 3DPG was demonstrated for entry-point accuracy, as the upper margin of the 95% CI (−1.01 mm−0.49 mm) for the difference between the means did not cross the predetermined non-inferiority margin of 1 mm (p < 0.05). We also demonstrated non-inferiority of 3D angular accuracy (p < 0.05), with a 95% CI for the true difference of −2.30°−1.35°, not crossing the predetermined non-inferiority margin of 3° (p < 0.05). The results of this randomized controlled trial (RCT) showed that 3DPGs provide a non-inferior alternative to CAS in terms of screw insertion accuracy and have considerable potential as a navigational technique in spinal fixation.

Radiation Exposure in Posterior Lumbar Fusion: A Comparison of CT Image-Guided Navigation, Robotic Assistance, and Intraoperative Fluoroscopy

STUDY DESIGN

Retrospective clinical review.

OBJECTIVE

To assess the use of intraoperative computed tomography (CT) image-guided navigation (IGN) and robotic assistance in posterior lumbar surgery and their relationship with patient radiation exposure and perioperative outcomes.

METHODS

Patients ≥18 years old undergoing 1- to 2-level transforaminal lateral interbody fusion in 12-month period were included. Chart review was performed for pre- and intraoperative data on radiation dose and perioperative outcomes. All radiation doses are quantified in milliGrays (mGy). Univariate analysis and multivariate logistic regression analysis were utilized for categorical variables. One-way analysis of variance with post hoc Tukey test was used for continuous variables.

RESULTS

A total of 165 patients were assessed: 12 IGN, 62 robotic, 56 open, 35 fluoroscopically guided minimally invasive surgery (MIS). There was a lower proportion of women in open and MIS groups (P = .010). There were more younger patients in the MIS group (P < .001). MIS group had the lowest mean posterior levels fused (P = .015). Total-procedure radiation, total-procedure radiation/level fused, and intraoperative radiation was the lowest in the open group and highest in the MIS group compared with IGN and robotic groups (all P < .001). Higher proportion of robotic and lower proportion of MIS patients had preoperative CT (P < .001). Estimated blood loss (P = .002) and hospital length of stay (P = .039) were lowest in the MIS group. Highest operative time was observed for IGN patients (P < .001). No differences were observed in body mass index, Charlson Comorbidity Index, and postoperative complications (P = .313, .051, and .644, respectively).

CONCLUSION

IGN and robotic assistance in posterior lumbar fusion were associated with higher intraoperative and total-procedure radiation exposure than open cases without IGN/robotics, but significantly less than MIS without IGN/robotics, without differences in perioperative outcomes. Fluoro-MIS procedures reported highest radiation exposure to patient, and of equal concern is that the proportion of total radiation dose also applied to the surgeon and operating room staff in fluoro-MIS group is higher than in IGN/robotics and open groups.

The Use of Image-Guided Navigation Systems During Spine Surgeries in Saudi Arabia: A Cross-Sectional Study

BACKGROUND

We used a cross-sectional study design (questionnaire) to investigate the use of image-guided navigation (IGN) in Saudi Arabia and explore possible differences in implementing IGN for daily practice.

METHODS

An internet-based survey was sent to all spine surgeons who are practicing in Saudi Arabia (orthopedics or neurosurgery). The survey is composed of 12 items that collected demographic and academic data.

RESULTS

Ninety-nine answered the questionnaire from 197; 80% were from Riyadh, the capital, and 50% were consultants (attending physicians). Orthopedic surgeons were almost 60% of responders compared to 40% neurosurgeons. The use of navigation in Saudi hospitals was high (76.8%). There was a significant difference between specialties in the preference of using navigation (23.2% for orthopedics versus 81.4% for neurosurgery, P < .001) and routine use in surgical spine cases (88.4% for neurosurgery versus 50.0% orthopedics, P < .001). The majority of responders from neurosurgery learned to use navigation during residency compared to orthopedics responders (51.2% versus 28.6%, P = .001). More than 30% of orthopedics responders expressed they never learned navigation compared to only 4% of neurosurgery responders. The comfort level of > 75% with performing surgery using navigation was significantly different between specialties (25% for orthopedics versus 46.5% for neurosurgery, P < .001).

CONCLUSION

Saudi spine surgeons are among the highest users of IGN systems. The strong healthcare infrastructure and the availability of these devices across the country are among the most important factors for its prevalence. Enhancing surgical exposure and education of postgraduate trainees to use these tools, especially within orthopedics, could increase use and comfort level rates.

Management of Cerebrospinal Fluid Rhinorrhea in the Sphenoid Sinus Lateral Recess Through an Endoscopic Endonasal Transpterygoid Approach With Obliteration of the Lateral Recess

BACKGROUND

Cerebrospinal fluid rhinorrhea in the sphenoid sinus lateral recess is a rare occurrence and poses unique challenges due to limited surgical access for surgical repair.

OBJECTIVE

To report our experience of surgical repair of cerebrospinal fluid rhinorrhea in the sphenoid sinus lateral recess through an endoscopic endonasal transpterygoid approach with obliteration of the lateral recess. To evaluate the efficiency of this surgical procedure.

METHODS

A retrospective study. Twelve cases with cerebrospinal fluid rhinorrhea in the sphenoid sinus lateral recess were reviewed. Assisted by image-guided navigation, cerebrospinal fluid rhinorrhea was repaired through an endoscopic endonasal transpterygoid approach, with obliteration of the lateral recess. Complications and recurrence were recorded. Medical photographs were used.

RESULTS

This surgical approach provided a relatively spacious corridor to dissect the sphenoid sinus lateral recess and do postoperative surveillance. The repair area completely healed in 3 months after surgery. Cerebrospinal fluid rhinorrhea in the sphenoid sinus lateral recess was successfully repaired on the first attempt in all cases (100%). No main complications or recurrence was observed during a mean follow-up time of 40.3 months.

CONCLUSION

The endoscopic endonasal transpterygoid approach gives appropriate access for the treatment of spontaneous cerebrospinal fluid rhinorrhea in the sphenoid sinus lateral recess. Multilayer reconstruction of a skull base defect with obliteration of the lateral recess is a reliable and simple method.

Medial Rectus Anastomosis Under Endoscopic Endonasal Orbital Approach With Image-Guided Navigation: A New Way of Repairing a Ruptured Medial Rectus

BACKGROUND

With the extensive development of endoscopic sinus surgery, iatrogenic medial rectus muscle injury should be treated with caution. Traditional methods to repair a ruptured medial rectus need an anterior orbitotomy approach, with more injury and difficulty in finding the posterior end of the ruptured medial rectus.

OBJECTIVE

To explore a new method to repair a ruptured medial rectus.

METHODS

Eight cases of iatrogenic medial rectus rupture after endoscopic sinus surgery were reviewed from July 2015 to January 2019. Assisted by image-guided navigation, the ruptured medial rectus was sutured under an endoscopic endonasal orbital approach. Two methods were designed to suture the ruptured medial rectus. Optic nerve and orbital decompression were performed in 5 cases with visual impairment. The extent of exotropia and diplopia were followed up for 5 to 33 months after surgery.

RESULTS

With the help of image guidance, the posterior and anterior ends of the ruptured medial rectus of all patients were pinpointed, and operations using medial rectus anastomosis were successfully completed in 7 patients. The exotropia of these patients was corrected, and they have recovered. The vision of 2 patients recovered. There were no minor or major complications intraoperatively or postoperatively.

CONCLUSION

Assisted by image-guided navigation, medial rectus anastomosis under an endoscopic endonasal orbital approach is a feasible method. The key to preventing orbital complications is strict professional training, including identification of the Onodi air cell and correct application of powered instrumentation.

Pediatric hydrocephalus: systematic literature review and evidence-based guidelines. Part 3: Endoscopic computer-assisted electromagnetic navigation and ultrasonography as technical adjuvants for shunt placement

OBJECT

This systematic review was undertaken to answer the following question: Do technical adjuvants such as ventricular endoscopic placement, computer-assisted electromagnetic guidance, or ultrasound guidance improve ventricular shunt function and survival?

METHODS

The US National Library of Medicine PubMed/MEDLINE database and the Cochrane Database of Systematic Reviews were queried using MeSH headings and key words specifically chosen to identify published articles detailing the use of cerebrospinal fluid shunts for the treatment of pediatric hydrocephalus. Articles meeting specific criteria that had been delineated a priori were then examined, and data were abstracted and compiled in evidentiary tables. These data were then analyzed by the Pediatric Hydrocephalus Systematic Review and Evidence-Based Guidelines Task Force to consider evidence-based treatment recommendations.

RESULTS

The search yielded 163 abstracts, which were screened for potential relevance to the application of technical adjuvants in shunt placement. Fourteen articles were selected for full-text review. One additional article was selected during a review of literature citations. Eight of these articles were included in the final recommendations concerning the use of endoscopy, ultrasonography, and electromagnetic image guidance during shunt placement, whereas the remaining articles were excluded due to poor evidence or lack of relevance. The evidence included 1 Class I, 1 Class II, and 6 Class III papers. An evidentiary table of relevant articles was created. CONCLUSIONS/RECOMMENDATION: There is insufficient evidence to recommend the use of endoscopic guidance for routine ventricular catheter placement.

STRENGTH OF RECOMMENDATION

Level I, high degree of clinical certainty.

RECOMMENDATION

The routine use of ultrasound-assisted catheter placement is an option.

STRENGTH OF RECOMMENDATION

Level III, unclear clinical certainty.

RECOMMENDATION

The routine use of computer-assisted electromagnetic (EM) navigation is an option.

STRENGTH OF RECOMMENDATION

Level III, unclear clinical certainty.

Less is sometimes more: a comparison of distance-control and navigated-control concepts of image-guided navigation support for surgeons

Image-guided navigation (IGN) systems provide automation support of intra-operative information analysis and decision-making for surgeons. Previous research showed that navigated-control (NC) systems which represent high levels of decision-support and directly intervene in surgeons' workflow provide benefits with respect to patient safety and surgeons' physiological stress but also involve several cost effects (e.g. prolonged surgery duration, reduced secondary-task performance). It was hypothesised that less automated distance-control (DC) systems would provide a better solution in terms of human performance consequences. N = 18 surgeons performed a simulated mastoidectomy with NC, DC and without IGN assistance. Effects on surgical performance, physiological effort, workload and situation awareness (SA) were compared. As expected, DC technology had the same benefits as the NC system but also led to less unwanted side effects on surgery duration, subjective workload and SA. This suggests that IGN systems just providing information analysis support are overall more beneficial than higher automated decision-support.

PRACTITIONER SUMMARY

This study investigates human performance consequences of different concepts of IGN support for surgeons. Less automated DC systems turned out to provide advantages for patient safety and surgeons' stress similar to higher automated NC systems with, at the same time, reduced negative consequences on surgery time and subjective workload.

Same day tri-modality functional brain mapping prior to resection of a lesion involving eloquent cortex: technical feasibility

Non-invasive functional evaluation of the brain complements structural MRI imaging and has largely supplanted invasive techniques such as awake craniotomy. Techniques used for functional mapping of the brain include BOLD-functional MRI (fMRI), magnetoencephalography (MEG), and transcranial magnetic stimulation (TMS). We describe the case of a right-handed patient with a lesion centered in the left inferior perirolandic cortex who underwent fMRI, MEG, and TMS on a single day to facilitate maximal lesion resection while preserving eloquent cortex and eloquent white matter tracts.

Impact of navigated-control assistance on performance, workload and situation awareness of experienced surgeons performing a simulated mastoidectomy

BACKGROUND

Navigated control (NC) is an advanced image-guided navigation system that provides an additional control function to enhance patient safety. It automatically stops the surgical instrument if it comes close to critical anatomical structures that need to be protected during surgery. The purpose of this study was to explore the human performance consequences of computer-based navigated control assistance.

METHODS

Seven experienced surgeons conducted a simulated mastoidectomy manually and with support of the NC system. The impact on surgical performance, workload and situation awareness was analysed.

RESULTS

NC support led to a better quality of surgical outcome and a lower level of physiological effort during surgery. Cost effects were reflected in reduced time efficiency and an increased subjectively experienced workload.

CONCLUSION

The results demonstrate the potential of NC support in terms of lower workload and enhanced patient safety. Cost effects might be reduced by remodelling the control function.