Computational surgery in the management of patients with abdominal aortic aneurysms: Opportunities, challenges, and future directions.

Computational surgery (CS) is an interdisciplinary field that uses mathematical models and algorithms to focus specifically on operative planning, simulation, and outcomes analysis to improve surgical care provision. As the digital revolution transforms the surgical work environment through broader adoption of artificial intelligence and machine learning, close collaboration between surgeons and computational scientists is not only unavoidable, but will become essential. In this review, the authors summarize the main advances, as well as ongoing challenges and prospects, that surround the implementation of CS techniques in vascular surgery, with a particular focus on the care of patients affected by abdominal aortic aneurysms (AAAs). Several key areas of AAA care delivery, including patient-specific modelling, virtual surgery simulation, intraoperative imaging-guided surgery, and predictive analytics, as well as biomechanical analysis and machine learning, will be discussed. The overarching goals of these CS applications is to improve the precision and accuracy of AAA repair procedures, while enhancing safety and long-term outcomes. Accordingly, CS has the potential to significantly enhance patient care across the entire surgical journey, from preoperative planning and intraoperative decision making to postoperative surveillance. Moreover, CS-based approaches offer promising opportunities to augment AAA repair quality by enabling precise preoperative simulations, real-time intraoperative navigation, and robust postoperative monitoring. However, integrating these advanced computer-based technologies into medical research and clinical practice presents new challenges. These include addressing technical limitations, ensuring accuracy and reliability, and managing unique ethical considerations associated with their use. Thorough evaluation of these aspects of advanced computation techniques in AAA management is crucial before widespread integration into health care systems can be achieved.

Higher Accuracy and Better Clinical Outcomes in Navigated Thoraco-Lumbar Pedicle Screw Fixation Versus Conventional Techniques : A Systematic Review and Meta-Analysis.

STUDY DESIGN: A systematic review and meta-analysis. OBJECTIVE: This study aims to compare pedicle screw accuracy, clinical outcomes, and complications between navigated and conventional techniques. SUMMARY OF BACKGROUND DATA: In the last decades, intraoperative navigation has been introduced in spinal surgery to prevent risks and complications. MATERIALS AND METHODS: The search was executed on Cochrane Central Library, PubMed, and Scopus on April 30, 2023. Randomized controlled trials, prospective and retrospective studies that compared pedicle screw accuracy in the thoracic-lumbar-sacral segments, blood loss, operative time, hospital stay, intraoperative and postoperative revision of screws, neurological and systemic complications, Visual Analogue Scale (VAS), and Oswestry Disability Index (ODI) between navigated and freehand or fluoroscopy-assisted techniques were included in this study. The meta-analysis was performed using Review Manager software. Clinical outcomes were assessed as continuous outcomes with mean difference, while pedicle screw accuracy and complications were assessed as dichotomous outcomes with odds ratio, all with 95% CIs. The statistical significance of the results was fixed at P <0.05. RESULTS: This meta-analysis included 30 studies for a total of 17,911 patients and 24,600 pedicle screws. Statistically significant results in favor of the navigated technique were observed for the accuracy of pedicle screws ( P =0.0001), hospital stay ( P =0.0002), blood loss ( P <0.0001), postoperative revision of pedicle screws ( P <0.00001), and systemic complications ( P =0.0008). In particular, the positioning of the screws was clinically acceptable in 96.2% of the navigated group and 94.2% with traditional techniques. No significant differences were found in VAS, ODI, and operative time between the two groups. CONCLUSION: Navigated pedicle screw fixation has been demonstrated to be a safe and effective technique with high improvement in clinical outcomes and accuracy in patients undergoing spinal fusion compared with conventional techniques. LEVEL OF EVIDENCE: Level III.

Low-dose radio-guided parathyroidectomy: A non-inferiority systematic review and meta-analysis.

BACKGROUND: Performing MIRP procedure with a 20-fold less MIBI isotope dose allows lower radiation exposure risk for both patient and staff and reduce the overall cost of the procedure. The main goal of this systemic review and meta-analysis is to prove the non-inferiority of the very low dose MIRP compared to the standard dose. METHODS: We performed a systemic review and meta-analysis of three different electronic databases - PubMed, Web of Science and google scholar. Meta-extraction was conducted in accordance with PRISMA guidelines. RESULTS: Among 4750 studies imported for screening, only 13 studies were selected for the meta-analysis. Analyzed data from the 13 selected studies performed with low dose MIRP demonstrated a detection rate greater than 97 â€‹% and a success rate greater than 95 â€‹%, which is comparable to the cure rate required by current guidelines, as well as to data published by studies using the original high dose protocol. CONCLUSION: Very low dose MIRP is not inferior to the high dose original MIRP and may be used in separate day protocol routinely.

Surgical and Percutaneous Image-Guided Therapies of Abdominal Wall Endometriosis: A Systematic Review of Current Evidence.

OBJECTIVE: Despite various surgical and nonsurgical strategies for abdominal wall endometriosis, the lack of definitive guidance on optimal treatment choice leads to clinical uncertainty. This review scrutinizes the safety and efficacy of abdominal wall endometriosis treatments to aid in decision-making. DATA SOURCES: We performed a systematic literature review of PubMed, Embase, and Cochrane Library databases from 1947 until December 2023. METHODS OF STUDY SELECTION: A comprehensive literature search identified studies that assessed both surgical and nonsurgical interventions, including high-intensity focused ultrasound (HIFU), cryoablation, radiofrequency ablation, and microwave ablation. This review is registered in NIHR-PROSPERO (CRD 42023494969). Local tumor control (LTC), local pain relief (LPR), and adverse events (AE) were recorded. TABULATION, INTEGRATION, AND RESULTS: This review included 51 articles among 831 identified. All study designs were considered eligible for inclusion. A total of 2674 patients are included: 2219 patients (83%) undergoing surgery, and 455 (17%) undergoing percutaneous interventions (342 HIFU, 103 cryoablation, 1 radiofrequency ablation, 9 microwave ablation). Follow-up length was 18 months in median, ranging from 1 to 235 months. Overall LTC rates ranged from 86% to 100%. Surgical interventions consistently demonstrated the highest rate of LTC with a median rate of 100%, and LPR with a median rate of 98.2% (95% confidence interval [CI]: 93.9-97.7). HIFU showed median LTC and LPR rates, respectively of 95.65% (95% CI, 87.7-99.9) and 76.1% (95% CI, 61.8-90.4); and cryoablation of 85.7% (95% CI, 66.0-99.9) and 79.2% (95% CI, 67.4-91.03). Minor AE was reported after surgery in 17.5% of patients (225/1284) including 15.9% (199/1284) of mesh implantation; 76.4% (239/313) after HIFU; and 8.7% (9/103) after cryoablation. Severe AE was reported in 25 patients in the surgery group and 1 in the percutaneous group. CONCLUSION: The safety profile and efficacy of nonsurgical interventions support their clinical utility for management of abdominal wall endometriosis.

The Use of Advanced Three-Dimensional Computed Tomography During Simple and Complex Endovascular Aortic Aneurysm Repairs.

BACKGROUND: Endovascular aneurysm repair (EVAR) success depends on imaging technology both in the planning and operative phases. Endovascular repair requires intravenous contrast and radiation exposure to the patient as well as radiation exposure to the operator. Recent developments in imaging technology attempt to merge preoperative imaging with intraoperative imaging to improve the efficiency and accuracy of EVAR. The Cydar 3-dimensional (3D) imaging system combines the preoperative and intraoperative imaging during the operation. We aim to investigate the use of the Cydar 3D imaging system during EVAR compared to conventional methods. METHODS: Retrospective review of all patients undergoing an EVAR at a single quaternary vascular center from 2019-2023 was collected. This cohort was divided into 2 groups: (1) repair using Cydar 3D imaging or (2) repair without Cydar 3D imaging. Overall, 138 unique patients were identified with 27 operations using Cydar 3D imaging and 111 operations without Cydar 3D imaging. We performed a 1-to-1 propensity score-matched analysis using nearest-neighbor matching for variables including age, case urgency, and if the case was performed in the operative room or interventional radiology room. A match occurred when a patient in the Cydar 3D imaging group had an estimated score within 0.01 standard deviations of a patient in the control group. From this, we paired 27 from each cohort for a total of 54 patients. Demographic data included length of stay in days, contrast volume (mL), fluoroscopy time (min), procedure length (mins), mortality, and blood loss (mL). Univariate analyses were performed and a P value less than 0.05 was considered statistically significant. RESULTS: A total of 54 vascular patients were analyzed: 27 without the Cydar 3D imaging and 27 with the Cydar 3D imaging. In the univariate analysis, there was no statistical difference in the average length of stay (6.4 days ± 11.76 vs. 4.1 ± 6.03, P = 0.372), aneurysm size (5.9 ± 1.4 vs. 5.9 ± 1.2, P = 0.88), contrast volume in mL (91.3 ± 47.0 vs. 91.1-33.49, P = 9.88), fluoroscopy time in mins (20.2 ± 17.2 vs. 19.5 ± 19.4, P = 0.89), procedure length (299.3 ± 177.9 vs. 353 ± 191.98, P = 0.279), and blood loss in mL (513.8 ± 791 vs. 353 ± 191.98, P = 0.594). There was an increase in reintervention for endoleaks in the group with use of Cydar 3D imaging (0 vs. 6, P = 0.043). A subanalysis of patients undergoing physician-modified EVARs did show a 15% reduction in the contrast volume used. CONCLUSIONS: The use of 3D imaging technology has the potential to increase the safety of EVAR to both patients and operators. In our study, we did not find any difference in standard EVARs; however, there was a contrast use decrease in physician-modified EVARs. Further studies will need to be performed to determine the realized benefit from performing EVARs using this new technology.

Autofluorescence-Guided Total Thyroidectomy in Low-Volume, Nonparathyroid Institutions.

Importance: Hypoparathyroidism following thyroid surgery is a serious complication that occurs frequently when surgery is performed by low-volume thyroid surgeons without experience in parathyroid surgery. Objective: To evaluate the occurrence of hypoparathyroidism following total thyroidectomy after the introduction of autofluorescence in low-volume, nonparathyroid institutions. Design, Setting, and Participants: This prospective, multicenter cohort study, with a follow-up period of up to 1 year, was conducted in Denmark at 2 low-volume nonparathyroid institutions between January 2021 and November 2023. All adult patients referred for total thyroidectomy were assessed for eligibility (n = 90). Only patients with no history of thyroid surgery were considered (n = 89). Patients who only underwent lobectomy (n = 6) or declined to participate (n = 5) were excluded. All included patients completed follow-up. The prospective cohort was compared with a historical cohort of successive patients undergoing primary total thyroidectomy from 2016 to 2020 (before autofluorescence was available). Intervention: Included patients underwent autofluorescence-guided total thyroidectomy. Main outcomes and Measures: Rate of hypoparathyroidism. Immediate hypoparathyroidism was defined as the need for active vitamin D postoperatively, whereas permanent hypoparathyroidism was considered when there still was a need for active vitamin D 1 year after surgery. Results: Seventy-eight patients underwent autofluorescence-guided surgery (mean [SD] age, 55.6 [13.1] years; 67 [86%] female) and were compared with 89 patients in the historical cohort (mean [SD] age, 49.7 [12.8] years; 78 [88%] female). The rate of immediate hypoparathyroidism decreased from 37% (95% CI, 27%-48%) to 19% (95% CI, 11%-30%) after the introduction of autofluorescence (P = .02). Permanent hypoparathyroidism rates decreased from 32% (95% CI, 22%-42%) to 6% (95% CI, 2%-14%) (P < .001), reaching 0% at the end of the study. More parathyroid glands were identified with autofluorescence (75% [95% CI, 70%-80%] vs 61% [95% CI, 56%-66%]) (P < .001) and less parathyroid glands were inadvertently excised (4% [95% CI, 1%-11%] vs 21% [95% CI, 13%-31%]) (P = .001). Conclusions and Relevance: In this cohort study of autofluorescence-guided thyroid surgery in low-volume, nonparathyroid institutions, the use of autofluorescence was associated with a significant decrease in both immediate and permanent hypoparathyroidism. When autofluorescence was used, hypoparathyroidism rates were comparable with those of high-volume surgeons who also perform parathyroid surgery.

Pedicle screw placement accuracy in robot-assisted versus image-guided freehand surgery of thoraco-lumbar spine (ROBARTHRODESE): study protocol for a single-centre randomized controlled trial.

BACKGROUND: Robotic spinal surgery may result in better pedicle screw placement accuracy, and reduction in radiation exposure and length of stay, compared to freehand surgery. The purpose of this randomized controlled trial (RCT) is to compare screw placement accuracy of robot-assisted surgery with integrated 3D computer-assisted navigation versus freehand surgery with 2D fluoroscopy for arthrodesis of the thoraco-lumbar spine. METHODS: This is a single-centre evaluator-blinded RCT with a 1:1 allocation ratio. Participants (n = 300) will be randomized into two groups, robot-assisted (Mazor X Stealth Edition) versus freehand, after stratification based on the planned number of pedicle screws needed for surgery. The primary outcome is the proportion of pedicle screws placed with grade A accuracy (Gertzbein-Robbins classification) on postoperative computed tomography images. The secondary outcomes are intervention time, operation room occupancy time, length of stay, estimated blood loss, surgeon's radiation exposure, screw fracture/loosening, superior-level facet joint violation, complication rate, reoperation rate on the same level or one level above, functional and clinical outcomes (Oswestry Disability Index, pain, Hospital Anxiety and Depression Scale, sensory and motor status) and cost-utility analysis. DISCUSSION: This RCT will provide insight into whether robot-assisted surgery with the newest generation spinal robot yields better pedicle screw placement accuracy than freehand surgery. Potential benefits of robot-assisted surgery include lower complication and revision rates, shorter length of stay, lower radiation exposure and reduction of economic cost of the overall care. TRIAL REGISTRATION: ClinicalTrials.gov NCT05553028. Registered on September 23, 2022.

Intraoperative navigation increases the projected lifetime cancer risk in patients undergoing surgery for adolescent idiopathic scoliosis.

BACKGROUND CONTEXT: Adolescent idiopathic scoliosis (AIS) is a common condition, often requiring surgical correction. Computed tomography (CT) based navigation technologies, which rely on ionizing radiation, are increasingly being utilized for surgical treatment. Although this population is highly vulnerable to radiation, given their age and female predominance, there is little available information elucidating modeled iatrogenic cancer risk. PURPOSE: To model lifetime cancer risk associated with the use of intraoperative CT-based navigation for surgical treatment of AIS. STUDY DESIGN/SETTING: This retrospective cross-sectional study took place in a quaternary care academic pediatric hospital in the United States. PATIENT SAMPLE: Adolescents aged 10-18 who underwent posterior spinal fusion for a diagnosis of AIS between July 2014 and December 2019. OUTCOMES MEASURES: Effective radiation dose and projected lifetime cancer risk associated with intraoperative doses of ionizing radiation. METHODS: Clinical and radiographic parameters were abstracted, including total radiation dose during surgery from flat plate radiographs, fluoroscopy, and intraoperative CT scans. Multivariable regression analysis was used to assess differences in radiation exposure between patients treated with conventional radiography versus intraoperative navigation. Radiation exposure was translated into lifetime cancer risk using well-established algorithms. RESULTS: In total, 245 patients were included, 119 of whom were treated with navigation. The cohort was 82.9% female and 14.4 years of age. The median radiation exposure (in millisieverts, mSv) for fluoroscopy, radiography, and navigation was 0.05, 4.14, and 8.19 mSv, respectively. When accounting for clinical and radiographic differences, patients treated with intraoperative navigation received 8.18 mSv more radiation (95%CI: 7.22-9.15, p<.001). This increase in radiation projects to 0.90 iatrogenic malignancies per 1,000 patients (95%CI 0.79-1.01). CONCLUSIONS: Ours is the first work to define cancer risk in the setting of radiation exposure for navigated AIS surgery. We project that intraoperative navigation will generate approximately one iatrogenic malignancy for every 1,000 patients treated. Given that spine surgery for AIS is common and occurs in the context of a multitude of other radiation sources, these data highlight the need for radiation budgeting protocols and continued development of lower radiation dose technologies. LEVEL OF EVIDENCE: Therapeutic, III.

Does a Commercially Available Augmented Reality-based Portable Hip Navigation System Improve Cup Positioning During THA Compared With the Conventional Technique? A Randomized Controlled Study.

BACKGROUND: Portable hip navigation systems have been developed to combine the accuracy of cup positioning by large console navigation systems with the ease of use and convenience of conventional surgical techniques. Although a novel augmented reality-based portable hip navigation system using a smartphone (AR navigation) has become available recently, no studies, to our knowledge, have compared commercially available AR navigation with the conventional technique. Additionally, no studies, except for those from designer-surgeon series, have demonstrated the results of AR navigation. QUESTIONS/PURPOSES: (1) Does intraoperative use of commercially available AR navigation improve cup positioning compared with the conventional technique? (2) Are operative factors, clinical scores, and postoperative course different between the two groups? METHODS: In this randomized trial, 72 patients undergoing THA were randomly assigned to undergo either commercially available AR navigation or a conventional technique for cup placement. All patients received the same cementless acetabular cups through a posterior approach in the lateral decubitus position. The primary outcome of the present study was cup positioning, including the absolute differences between the intended target and angle achieved, as well as the number of cups inside the Lewinnek safe zone. Our target cup position was 40° abduction and 20° anteversion. Secondary outcomes were operative factors, between-group difference in improvement in the Hip Disability and Osteoarthritis Outcome Score (HOOS), and the postoperative course, including the operative time (between the start of the surgical approach and skin closure), procedure time (between the first incision and skin closure, including the time to insert pins, registration, and transfer and redrape patients in the navigation group), time taken to insert pins and complete registration in the navigation group, intraoperative and postoperative complications, and reoperations. The minimum follow-up period was 6 months, because data regarding the primary outcome-cup positioning-were collected within 1 week after surgery. The between-group difference in improvement in HOOS, which was the secondary outcome, was much lower than the minimum clinically important difference for the HOOS. No patients in either group were lost to follow-up, and there was no crossover (the randomized treatment was performed in all patients, so there was no difference between an intention-to-treat and a per-protocol analysis). RESULTS: The use of the commercially available AR navigation slightly improved cup positioning compared with the conventional technique in terms of the absolute difference between the desired and achieved amounts of cup abduction and anteversion (which we defined as "absolute differences"; median 1° [IQR 0° to 4.0°] versus median 5° [IQR 3.0° to 7.5°], difference of medians 4°; p < 0.001 and median 2° [IQR 1.9° to 3.7°] versus median 5° [IQR 3.2° to 9.7°], difference of medians 2°; p = 0.001). A higher proportion of cups were placed inside the Lewinnek safe zone in the navigation group than in the control group (94% [34 of 36] compared with 64% [23 of 36]; p < 0.001). Median operative times were not different between the two groups (58 minutes [IQR 49 to 72 minutes] versus 57 minutes [IQR 49 to 69 minutes], difference of medians 1 minute; p = 0.99). The median procedure time was longer in the navigation group (95 minutes [IQR 84 to 109 minutes] versus 57 minutes [IQR 49 to 69 minutes], difference of medians 38 minutes; p < 0.001). There were no differences between the two groups in improvement in HOOS (27 ± 17 versus 28 ± 19, mean difference -1 [95% CI -9.5 to 7.4]; p = 0.81). In the navigation group, no complications occurred in the pin sites; however, one anterior dislocation occurred. In the conventional group, one hip underwent reoperation because of a deep infection. CONCLUSION: Although the use of commercially available AR navigation improved cup positioning in THA, the improvement in clinical scores and postoperative complication rates were not different between the two groups, and the overall magnitude of the difference in accuracy was small. Future studies will need to determine whether the improvement in the percentage of hips inside the Lewinnek safe zone results in differences in late dislocation or polyethylene wear, and whether such benefits-if any-justify the added costs and surgical time. Until or unless more compelling evidence in favor of the new system emerges, we recommend against widespread use of the system in clinical practice. LEVEL OF EVIDENCE: Level Ⅱ, therapeutic study.

Does Augmented Reality-based Portable Navigation Improve the Accuracy of Cup Placement in THA Compared With Accelerometer-based Portable Navigation? A Randomized Controlled Trial.

BACKGROUND: Previous studies reported good outcomes of acetabular cup placement using portable navigation systems during THA. However, we are aware of no prospective studies comparing inexpensive portable navigation systems using augmented reality (AR) technology with accelerometer-based portable navigation systems in THA. QUESTIONS/PURPOSES: (1) Is the placement accuracy of the acetabular cup using the AR-based portable navigation system superior to that of an accelerometer-based portable navigation system? (2) Do the frequencies of surgical complications differ between the two groups? METHODS: We conducted a prospective, two-arm, parallel-group, randomized controlled trial involving patients scheduled for unilateral THA. Between August and December 2021, we treated 148 patients who had a diagnosis of osteoarthritis, idiopathic osteonecrosis, rheumatoid arthritis, or femoral neck fracture and were scheduled to undergo unilateral primary THA. Of these patients, 100% (148) were eligible, 90% (133) were approached for inclusion in the study, and 85% (126) were finally randomized into either the AR group (62 patients) or the accelerometer group (64 patients). An intention-to-treat analysis was performed, and there was no crossover between groups and no dropouts; all patients in both groups were included in the analysis. There were no differences in any key covariates, including age, sex, and BMI, between the two groups. All THAs were performed via the modified Watson-Jones approach with the patient in the lateral decubitus position. The primary outcome was the absolute difference between the cup placement angle displayed on the screen of the navigation system and that measured on postoperative radiographs. The secondary outcome was intraoperative or postoperative complications recorded during the study period for the two portable navigation systems. RESULTS: There were no differences between the AR and accelerometer groups in terms of the mean absolute difference in radiographic inclination angle (3° ± 2° versus 3° ± 2° [95% CI -1.2° to 0.3°]; p = 0.22). The mean absolute difference in radiographic anteversion angle displayed on the navigation screen during surgery compared with that measured on postoperative radiographs was smaller in the AR group than that in the accelerometer group (2° ± 2° versus 5° ± 4° [95% CI -4.2° to -2.0°]; p < 0.001). There were few complications in either group. In the AR group, there was one patient each with a surgical site infection, intraoperative fracture, distal deep vein thrombosis, and intraoperative pin loosening; in the accelerometer group, there was one patient each with an intraoperative fracture and intraoperative loosening of pins. CONCLUSION: Although the AR-based portable navigation system demonstrated slight improvements in radiographic anteversion of cup placement compared with the accelerometer-based portable navigation system in THA, whether those small differences will prove clinically important is unknown. Until or unless future studies demonstrate clinical advantages that patients can perceive that are associated with such small radiographic differences, because of the costs and the unquantified risks associated with novel devices, we recommend against the widespread use of these systems in clinical practice. LEVEL OF EVIDENCE: Level I, therapeutic study.

Adverse Events Associated With Image-Guided Sinus Navigation in Endoscopic Sinus Surgery: A MAUDE Database Analysis.

OBJECTIVE: The utilization of image-guided navigation during endoscopic sinus surgery (ESS) has increased significantly since its introduction. However, the most common associated complications are still unknown. This study describes and analyzes adverse events related to image-guided ESS. STUDY DESIGN: Cross-sectional analysis. SETTING: The Food and Drug Administration's 2018-2022 MAUDE database (Manufacturer and User Facility Device Experience). METHODS: The MAUDE database was searched for all reports on adverse events involving sinus navigation systems used in ESS from 2018 to 2022. Reported events were reviewed and categorized. RESULTS: During the study period, there were 1857 adverse events from 1565 reports, which were divided into device-related (n = 1834, 98.8%) and patient-related (n = 23, 1.2%) complications. The most common device-related complications were nonfunctionality of the system (n = 512, 27.9%), device imprecision (n = 427, 23.3%), and device sensing problems (n = 277, 15.1%). The most common patient-related complications were cerebrospinal fluid (CSF) leak (n = 14, 60.9%), intracranial injury (n = 4, 17.4%), and bleeding/hemorrhage (n = 3, 13.1%). Imprecision was associated with increased risk of navigation abortion by the surgeon (odds ratio, 1.50 [95% CI, 1.38-1.65]; P < .001) and increased risk of CSF leak (odds ratio, 16.5 [95% CI, 3.66-74.0]; P < .001) as compared with other device-related complications. CONCLUSIONS: The most commonly reported device- and patient-related adverse events associated with image-guided sinus navigation systems were device nonfunction, imprecision, device sensing difficulties, and CSF leak. When imprecise navigation occurred, there was an increased likelihood of CSF leak and navigation abortion by the surgeon. Health care providers should be mindful of these possible complications when electing to use image-guided sinus navigation during ESS.

Robotic and navigated pedicle screws are safer and more accurate than fluoroscopic freehand screws: a systematic review and meta-analysis.

BACKGROUND CONTEXT: Navigated and robotic pedicle screw placement systems have been developed to improve the accuracy of screw placement. However, the literature comparing the safety and accuracy of robotic and navigated screw placement with fluoroscopic freehand screw placement in thoracolumbar spine surgery has been limited. PURPOSE: To perform a systematic review and meta-analysis of randomized control trials that compared the accuracy and safety profiles of robotic and navigated pedicle screws with fluoroscopic freehand pedicle screws. STUDY DESIGN/SETTING: Systematic review and meta-analysis PATIENT SAMPLE: Only randomized controlled trials comparing robotic-assisted or navigated pedicle screws placement with freehand pedicle screw placement in the thoracolumbar spine were included. OUTCOME MEASURES: Odds ratio (OR) estimates for screw accuracy according to the Gertzbein-Robbins scale and relative risk (RR) for various surgical complications. METHODS: We systematically searched PubMed and EMBASE for English-language studies from inception through April 7, 2022, including references of eligible articles. The search was conducted according to PRISMA guidelines. Two reviewers conducted a full abstraction of all data, and one reviewer verified accuracy. Information was extracted on study design, quality, bias, participants, and risk estimates. Data and estimates were pooled using the Mantel-Haenszel method for random-effects meta-analysis. RESULTS: A total of 14 papers encompassing 12 randomized controlled trials were identified (n=892 patients, 4,046 screws). The pooled analysis demonstrated that robotic and navigated pedicle screw placement techniques were associated with higher odds of screw accuracy (OR 2.66, 95% CI 1.24-5.72, p=.01). Robotic and navigated screw placement was associated with a lower risk of facet joint violations (RR 0.09, 95% CI 0.02-0.38, p<.01) and major complications (RR 0.31, 95% CI 0.11-0.84, p=.02). There were no observed differences between groups in nerve root injury (RR 0.50, 95% CI 0.11-2.30, p=.37), or return to operating room for screw revision (RR 0.28, 95% CI 0.07-1.13, p=.07). CONCLUSIONS: These estimates suggest that robotic and navigated screw placement techniques are associated with higher odds of screw accuracy and superior safety profile compared with fluoroscopic freehand techniques. Additional randomized controlled trials will be needed to further validate these findings.

Augmented reality in minimally invasive spine surgery: early efficiency and complications of percutaneous pedicle screw instrumentation.

BACKGROUND CONTEXT: Augmented reality (AR) employs an optical projection directly onto the user's retina, allowing complex image overlay on the natural visual field. In general, pedicle screw accuracy rates have improved with increasingly use of technology, with navigation-based instrumentation described as accurate in 89%-100% of cases. Emerging AR technology in spine surgery builds upon current spinal navigation to provide 3-dimensional imaging of the spine and powerfully reduce the impact of inherent ergonomic and efficiency difficulties. PURPOSE: This publication describes the first known series of in vivo pedicle screws placed percutaneously using AR technology for MIS applications. STUDY DESIGN / SETTING: After IRB approval, 3 senior surgeons at 2 institutions contributed cases from June, 2020 - March, 2022. 164 total MIS cases in which AR used for placement of percutaneous pedicle screw instrumentation with spinal navigation were identified prospectively. PATIENT SAMPLE: 155 (94.5%) were performed for degenerative pathology, 6 (3.6%) for tumor and 3 (1.8%) for spinal deformity.  These cases amounted to a total of 606 pedicle screws; 590 (97.3%) were placed in the lumbar spine, with 16 (2.7%) thoracic screws placed. OUTCOME MEASURES: Patient demographics and surgical metrics including total posterior construct time (defined as time elapsed from preincision instrument registration to final screw placement), clinical complications and instrumentation revision rates were recorded in a secure and de-identified database. METHODS: The AR system used features a wireless headset with transparent near-eye display which projects intra-operative 3D imaging directly onto the surgeon's retina. After patient positioning, 1 percuntaneous and 1 superficial reference marker are placed. Intra-operative CT data is processed to the headset and integrates into the surgeon's visual field creating a "see-through" 3D effect in addition to 2D standard navigation images. MIS pedicle screw placement is then carried out percutaneously through single line of sight using navigated instruments. RESULTS: Time elapsed from registration and percutaneous approach to final screw placement averaged 3 minutes and 54 seconds per screw.  Analysis of the learning curve revealed similar surgical times in the early cases compared to the cases performed with more experience with the system.  No instrumentation was revised for clinical or radiographic complication at final available follow-up ranging from 6-24 months. A total of 3 screws (0.49%) were replaced intra-operatively. No clinical effects via radiculopathy or neurologic deficit postoperatively were noted. CONCLUSIONS: This is the first report of the use of AR for placement of spinal pedicle screws using minimally invasive techniques.   This series of 164 cases confirmed efficiency and safety of screw placement with the inherent advantages of AR technologies over legacy enabling technologies.

Tips and pitfalls to improve accuracy and reduce radiation exposure in intraoperative CT navigation for pediatric scoliosis: a systematic review.

BACKGROUND CONTEXT: An increasing number of medical centers are adopting an intraoperative computed tomography (iCT) navigation system (iCT-Navi) to provide three-dimensional navigation for pediatric scoliosis surgery. While iCT-Navi has been reported to provide higher pedicle screw (PS) insertion accuracy, it may also result in higher radiation exposure to the patient. What innovations and studies have been introduced to reduce radiation exposure and further improve PS insertion? PURPOSE: Evaluate the level of evidence and quality of papers while categorizing the tips and pitfalls regarding pediatric scoliosis surgery using iCT-Navi. Compare iCT-Navi with other methods, including preoperative CT navigation. STUDY DESIGN: Systematic review. PATIENT SAMPLE: Articles on pediatric scoliosis surgery with iCT-Navi published through to June 2022. OUTCOME MEASURES: PS perforation rate and patient intraoperative radiation dose. METHODS: Following PRISMA guidelines, the Cochrane Library, Google Scholar, and PubMed databases were searched for articles satisfying the criteria of iCT-Navi use and pediatric scoliosis surgery. The level of evidence and quality of the articles meeting the criteria were evaluated according to the guidelines of the North American Spine Society and American Academy of Orthopedic Surgeons, respectively. The articles were also categorized by theme and summarized in terms of PS insertion accuracy and intraoperative radiation dose. The origins and characteristics of five major classification methods of PS perforation grade were summarized as well. RESULTS: The literature search identified 811 studies, of which 20 papers were included in this review. Overall, 513 pediatric scoliosis patients (381 idiopathic, 44 neuromuscular, 39 neurofibromatosis type 1, 28 congenital, 14 syndromic, seven other) were evaluated for PS perforations among 6,209 iCT-Navi insertions. We found that 232 (3.7%) screws were judged as major perforations (G2 or G3), 55 (0.9%) screws were judged as dangerous deviations (G3), and seven (0.1%) screws were removed. There were no reports of neurovascular injury caused by PSs. The risk factors for PS perforation included more than six vertebrae distance from the reference frame, more than nine consecutive insertions, upper thoracic level, thinner pedicle, upper instrumented vertebra proximity, short stature, and female. The accuracy of PS insertion did not remarkably decrease when the radiation dose was reduced to 1/5 or 1/10 by altering the iCT-Navi protocol. CONCLUSIONS: iCT-Navi has the potential to reduce PS perforation rates compared with other methods. The use of low-dose radiation protocols may not significantly affect PS perforation rates. Although several risk factors for PS perforation and measures to reduce radiation dose have been reported, the current evidence is limited by a lack of consistency in classifying PS perforation and evaluating patient radiation dose among studies. The standardization of several outcome definitions is recommended in this rapidly developing field.

Surgical Pitfalls in Bertolotti's syndrome management: A case report.

RATIONALE: Bertolotti's syndrome is one of the differential causes of low back pain, especially within young people. The etiopathogenesis of the typical paramedian low back pain, associated with Bertolotti's syndrome remains controversial, and there is no worldwide acceptance of treatment. PATIENT CONCERNS: This article presents the authors experience with surgical treatment of symptomatic patients with Bertolotti's syndrome. DIAGNOSES: Retrospective study of a selected series of patients with symptomatic Bertolotti's syndrome submitted to surgical treatment. INTERVENTIONS: This study included 16 patients, being 8 submitted to the new modified mini-open tubular microsurgical transverse processectomy, Among those patients, intraoperative fluoroscopy was used in 6 surgeries to locate the base of the enlarged transverse process (6/8); intraoperative neuromonitoring was used in 6 patients (6/8), 3D intraoperative advanced spinal image (O-arm) with neuronavigation was used to localize the base of the pseudojoint to be removed and to check the final bone resection for the last 5 cases (5/8). OUTCOMES: The average paramedian lower back pain before surgery on the visual analogue scale for pain in the 8 patients was 6.6 (range: 5-8) and reduced to 1.5 (range: 0-3) at the latest follow-up after surgery, while the average pain score of the radicular pain on the right or left side before the surgery was 1.3 (range: 0-6) and reduced to 0.6 (range: 0-7) after the surgery. LESSONS: The mini-open tubular microsurgical transverse processectomy seems to be potentially safe and effective for the surgical treatment of selected symptomatic patients with Bertolotti's syndrome.

Safety of CT-Guided Microwave Ablation of Subcardiac Liver Tumors.

PURPOSE: The purpose of this study was to investigate the safety of CT-guided microwave ablation (MWA) of subcardiac hepatic tumors. MATERIALS AND METHODS: This retrospective study included 19 patients (11 males and 8 females, age: 64.0 years (IQR: 58.3, 71.0) who underwent CT-guided MWA of 22 subcardiac tumors from January 2016 through December 2020. The subcardiac tumors consisted of 6 hepatocellular carcinomas and 16 metastases. Hydrodissection or other thermal protection technique was not used during the ablation. Subcardiac ablation was defined as the ablation zone extended ≤ 0.5 cm from myocardium or coronary artery. The safety of MWA of subcardiac tumors was evaluated based on procedural and post-procedural complications and intra-procedural ECG changes. Local tumor progression (LTP) was also analyzed and correlated with tumor and ablation zone sizes. RESULTS: The primary efficacy rate was 100%. The median follow-up was 20.5 months (IQR: 6.0, 29.8). There was no 30-day mortality. One grade 3 complication occurred (severe shoulder and chest pain), and there were 19 events of grade 1 or 2 complications. No instances of cardiac complications or significant procedural ECG changes were observed. There were 22 events of grade 1 and 2 laboratory toxicity and 1 event of grade 3 elevated bilirubin. The LTP was 13.6% at 1 year and 22.7% at 2 years. There was no significant correlation between LTP and tumor or ablation zone sizes. CONCLUSION: CT-guided MWA of subcardiac hepatic tumors is safe, and MWA should be considered as an option for managing subcardiac tumors. LTP rates for MWA of subcardiac tumors may be inferior to ablation of tumors in common location. LEVEL OF EVIDENCE III: Cohort Study.

Effect of MRI-Guided Fibrosis Ablation vs Conventional Catheter Ablation on Atrial Arrhythmia Recurrence in Patients With Persistent Atrial Fibrillation: The DECAAF II Randomized Clinical Trial.

Importance: Ablation of persistent atrial fibrillation (AF) remains a challenge. Left atrial fibrosis plays an important role in the pathophysiology of AF and has been associated with poor procedural outcomes. Objective: To investigate the efficacy and adverse events of targeting atrial fibrosis detected on magnetic resonance imaging (MRI) in reducing atrial arrhythmia recurrence in persistent AF. Design, Setting, and Participants: The Efficacy of Delayed Enhancement-MRI-Guided Fibrosis Ablation vs Conventional Catheter Ablation of Atrial Fibrillation trial was an investigator-initiated, multicenter, randomized clinical trial involving 44 academic and nonacademic centers in 10 countries. A total of 843 patients with symptomatic or asymptomatic persistent AF and undergoing AF ablation were enrolled from July 2016 to January 2020, with follow-up through February 19, 2021. Interventions: Patients with persistent AF were randomly assigned to pulmonary vein isolation (PVI) plus MRI-guided atrial fibrosis ablation (421 patients) or PVI alone (422 patients). Delayed-enhancement MRI was performed in both groups before the ablation procedure to assess baseline atrial fibrosis and at 3 months postablation to assess for ablation scar. Main Outcomes and Measures: The primary end point was time to first atrial arrhythmia recurrence after a 90-day blanking period postablation. The primary safety composite outcome was defined by the occurrence of 1 or more of the following events within 30 days postablation: stroke, PV stenosis, bleeding, heart failure, or death. Results: Among 843 patients who were randomized (mean age 62.7 years; 178 [21.1%] women), 815 (96.9%) completed the 90-day blanking period and contributed to the efficacy analyses. There was no significant difference in atrial arrhythmia recurrence between groups (fibrosis-guided ablation plus PVI patients, 175 [43.0%] vs PVI-only patients, 188 [46.1%]; hazard ratio [HR], 0.95 [95% CI, 0.77-1.17]; P = .63). Patients in the fibrosis-guided ablation plus PVI group experienced a higher rate of safety outcomes (9 [2.2%] vs 0 in PVI group; P = .001). Six patients (1.5%) in the fibrosis-guided ablation plus PVI group had an ischemic stroke compared with none in PVI-only group. Two deaths occurred in the fibrosis-guided ablation plus PVI group, and the first one was possibly related to the procedure. Conclusions and Relevance: Among patients with persistent AF, MRI-guided fibrosis ablation plus PVI, compared with PVI catheter ablation only, resulted in no significant difference in atrial arrhythmia recurrence. Findings do not support the use of MRI-guided fibrosis ablation for the treatment of persistent AF. Trial Registration: ClinicalTrials.gov Identifier: NCT02529319.

Accuracy and safety of robot-assisted cortical bone trajectory screw placement: a comparison of robot-assisted technique with fluoroscopy-assisted approach.

OBJECTIVE: To compare the safety and accuracy of cortical bone trajectory screw placement between the robot-assisted and fluoroscopy-assisted approaches. METHODS: This retrospective study was conducted between November 2018 and June 2020, including 81 patients who underwent cortical bone trajectory (CBT) surgery for degenerative lumbar spine disease. CBT was performed by the same team of experienced surgeons. The patients were randomly divided into two groups-the fluoroscopy-assisted group (FA, 44 patients) and the robot-assisted group (RA, 37 patients). Robots for orthopedic surgery were used in the robot-assisted group, whereas conventional fluoroscopy-guided screw placement was used in the fluoroscopy-assisted group. The accuracy of screw placement and rate of superior facet joint violation were assessed using postoperative computed tomography (CT). The time of single screw placement, intraoperative blood loss, and radiation exposure to the surgical team were also recorded. The χ2 test and Student's t-test were used to analyze the significance of the variables (P < 0.05). RESULTS: A total of 376 screws were inserted in 81 patients, including 172 screws in the robot-assisted group and 204 pedicle screws in the fluoroscopy-assisted group. Screw placement accuracy was higher in the RA group (160, 93%) than in the FA group (169, 83%) (P = 0.003). The RA group had a lower violation of the superior facet joint than the FA group. The number of screws reaching grade 0 in the RA group (58, 78%) was more than that in the FA group (56, 64%) (P = 0.041). Screw placement time was longer in the FA group (7.25 ± 0.84 min) than in the RA group (5.58 ± 1.22 min, P < 0.001). The FA group had more intraoperative bleeding (273.41 ± 118.20 ml) than the RA group (248.65 ± 97.53 ml, P = 0.313). The radiation time of the FA group (0.43 ± 0.07 min) was longer than the RA group (0.37 ± 0.10 min, P = 0.001). Furthermore, the overall learning curve tended to decrease. CONCLUSIONS: Robot-assisted screw placement improves screw placement accuracy, shortens screw placement time, effectively improves surgical safety and efficiency, and reduces radiation exposure to the surgical team. In addition, the learning curve of robot-assisted screw placement is smooth and easy to operate.

The application of augmented reality in craniofacial bone fracture reduction: study protocol for a randomized controlled trial.

BACKGROUND: Augmented reality (AR) is a new technology that increases users' perception of the real world. The purpose of this study is to evaluate the efficacy and safety of augmented reality navigation system in treatment with craniofacial fracture reduction. METHODS: This will be a single-center prospective randomized controlled trial. Twenty-two patients will be assigned to two groups of 11, and those with zygomaticomaxillary complex fractures will undergo preoperative three-dimensional CT modeling and have operational plans designed. The control team will use traditional optical navigation to perform the surgery, and the experimental team will use an AR navigation system. The primary outcome measures will be the accuracy of the key points of surgical area between the preoperational surgical plan and post-operation. The secondary outcome measures will be the blood loss, operation time, bone reduction time, hospital time, and complication rate. The findings obtained through this study are expected to evaluate efficacy and safety of the augmented reality navigation system in the treatment of zygomaticomaxillary complex fractures. DISCUSSION: This controlled trial of augmented reality navigation system in treatment with zygomaticomaxillary complex fracture reduction will clarify the efficacy and safety of this technology by measuring the accuracy of the key points of surgical area and blood loss, operation and bone reduction times, hospital stay duration, and complication rates. This is a single-center study, and the results are expected to promote the application of augmented reality in craniofacial fracture reduction to improve surgery accuracy and efficacy. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR1900022626 . Registered on April 19, 2019.

Imageless Computer Navigation Reduces 5-Year All-Cause Revision Rates After Primary Total Knee Arthroplasty.

BACKGROUND: The use of surgical navigation has been shown to reduce revision rates after total knee arthroplasty (TKA) in patients <65 years of age. It is unknown if this benefit extends to older patients. We hypothesized that the use of surgical navigation would reduce rates of all-cause revision in patients of all ages. METHODS: In this cohort study, we queried the Truven MarketScan all-payer database to identify patients who underwent TKA from 2007 to 2015. Current Procedural Terminology codes were used to create 2 groups based on whether intraoperative navigation was used. Demographics, comorbidities, complications, and revision rates were determined. International Classification of Diseases codes were used to determine reasons for revision. RESULTS: The conventional TKA cohort included 312,173 patients. The navigation cohort included 20,881 patients. There were not any clinically significant differences in demographics between the cohorts. All-cause revision rates were lower in the navigation cohort at 1 year (0.4% vs 0.5%, P = .04), 2 years (0.7% vs 0.9%, P = .003), and 5 years (0.9% vs 1.3%, P < .001) of follow-up. Revisions for mechanical loosening were more common in the conventional cohort (30.8% vs 21.9%, P = .009). Rates of revision for other causes, including infection, did not differ between groups, with the numbers available. CONCLUSION: The use of surgical navigation yielded a 30.7% reduction in the all-cause revision rate at 5-year follow-up compared to conventional TKA. This benefit increased as follow-up duration increased. Increased usage of this inexpensive technology, from the current 6.3% in this US cohort, may reduce healthcare costs. LEVEL OF EVIDENCE: III.