Use Of Intraoperative Computed Tomography Research Articles

Intraoperative computerised tomography scan for percutaneous fixation of the pelvis: a retrospective case series

PurposeFractures and dislocations of the pelvic ring are complex injuries that when treating require meticulous attention to detail and often specialized technical skill. These injuries can be the result of high-energy trauma, particularly in younger patients, or low energy trauma more often found in the elderly. Regardless of mechanism, these injuries lie on a spectrum of severity and can be treated conservatively or surgically. Percutaneous fixation under fluoroscopic guidance is the preferred standard technique when treating these fractures. This technique can be challenging for a variety of reasons including patient characteristics, intra-operative image quality, fracture morphology, among others.MethodsThis retrospective study evaluated the use of intra-operative computed tomography (CT) using an O-arm imaging system for critical evaluation of fluoroscopic-guided screw placement in twenty-three patients. We retrospectively reviewed all cases of patients who were treated by three fellowship-trained orthopaedic traumatologists during a one-year span. Patients undergoing percutaneous pelvis fixation using both standard fluoroscopy and intraoperative CT with the Medtronic O-arm® (Minneapolis, MN) imaging system. Additionally, procedures performed included open reduction internal fixation (ORIF) of the pelvic ring, acetabulum, and associated extremity fractures.ResultsTwenty-three patients were included in this study. On average, the use of intraoperative CT added 24.4 min in operative time. Five patients (21.7%) required implant adjustment after O-arm spin. Fourteen patients underwent additional post-operative CT. No secondary revision surgeries were attempted after any post-operative CT.ConclusionsOur study suggests that intra-operative CT scan, compared to post-operative CT scan, can be utilized to prevent take-back surgery for misplaced implants and allow for adjustment in real-time.

Orbital Fractures Treated in Auckland From 2016 to 2020: Review of Patient Outcomes

Orbital reconstruction is a complex procedure demanding accurate placement of implants to restore volume and anatomic shape to the orbits. Intra-operative computed-tomography (CT) and rapid-prototype (RP) biomodels have been recently introduced as surgical aids to improve outcomes. Investigation is required to determine if there is a reduction in post-operative ophthalmic complications. Study Design Retrospective cohort study. Objective To evaluate the impact of intra-operative CT and RP biomodels on the incidence of post-operative diplopia, paraesthesia, cosmetic issues and ability to return to work following orbital reconstruction surgery. Methods Adult (>18 years) patients treated at Counties Manukau District Health Board, Auckland, by the Department of Oral and Maxillofacial Surgery for isolated orbital fractures were retrospectively enrolled into this study. An audit of clinical records was undertaken to determine incidences of diplopia, altered sensation, cosmetic concerns and ability to return to work. These findings were compared against our previous audit which documented these findings in patients treated between 2010 and 2015, prior to the introduction of intra-operative CT and RP biomodels. Results Routine use of intra-operative CT and RP biomodels was associated with a reduced incidence of post-operative diplopia. No significant difference was observed with regards to paraesthesia and cosmetic deficits. Conclusions The relatively low radiation exposure and cost associated with intra-operative CT and RP biomodels is justified with improved outcomes in subjective diplopia. Titanium as a material for orbital reconstruction was confirmed to be associated with low complication rates.

Intraoperative Computed Tomography Use in Orbital Fracture Repair: A Systematic Review and Meta-Analysis.

Background: Intraoperative computed tomography (CT) allows surgeons to make adjustments during orbital fracture repair that may impact postoperative outcomes. Learning/Study Objectives: To determine the impact of intraoperative CT use on intraoperative revision and surgical outcomes for orbital fracture repair. Methods: A systematic review was performed in concordance with the Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) guidelines: the population was patients undergoing orbital fracture repair; intervention was use of intraoperative CT; comparison was patients not undergoing intraoperative CT; and outcomes were intraoperative revision rate, postoperative complications, and secondary revision surgeries. Meta-analysis was performed on the rate of intraoperative revision. Results: The search criteria yielded 790 articles, 377 were eligible for review, and 20 articles met criteria for analysis. In 19, intraoperative imaging led to immediate surgical corrections, with a random pooled effect size of 0.27 (0.20-0.35). Six studies reported secondary revision surgery rates (range 0-10.5%), and six studies reported postoperative complication rates (range 10-30%). Conclusions: Intraoperative imaging helps surgeons make precise, real-time adjustments in 27% of orbital fracture repair cases, which may improve surgical outcomes; however, more research is needed to investigate its impact on health care costs, operating time, and radiation exposure.

Projected lifetime cancer risk for patients undergoing spine surgery for isthmic spondylolisthesis

BACKGROUND CONTEXTRadiographs, fluoroscopy, and computed tomography (CT) are increasingly utilized in the diagnosis and management of various spine pathologies. Such modalities utilize ionizing radiation, a known cause of carcinogenesis. While the radiation doses such studies confer has been investigated previously, it is less clear how such doses translate to projected cancer risks, which may be a more interpretable metric. PURPOSE(1) Calculate the lifetime cancer risk and the relative contributions of preference-sensitive selection of imaging modalities associated with the surgical management of a common spine pathology, isthmic spondylolisthesis (IS); (2) Investigate whether the use of intraoperative CT, which is being more pervasively adopted, increases the risk of cancer. STUDY DESIGN/SETTINGRetrospective cross-sectional study carried out within a large integrated health care network. PATIENT SAMPLEAdult patients who underwent surgical treatment of IS via lumbar fusion from January 2016 through December 2021. OUTCOME MEASURES(1) Effective radiation dose and lifetime cancer risk associated with each exposure to ionizing radiation; (2) Difference in effective radiation dose (and lifetime cancer risk) among patients who received intraoperative CT compared to other intraoperative imaging techniques. METHODSBaseline demographics and differences in surgical techniques were characterized. Radiation exposure data were collected from the 2-year period centered on the operative date. Projected risk of cancer from this radiation was calculated utilizing each patient's effective radiation dose in combination with age and sex. Generalized linear modeling was used to adjust for covariates when determining the comparative risk of intraoperative CT as compared to alternative imaging modalities. RESULTSWe included 151 patients in this cohort. The range in calculated cancer risk exclusively from IS management was 1.3-13 cases of cancer per 1,000 patients. During the intraoperative period, CT imaging was found to significantly increase radiation exposure as compared to alternate imaging modalities (adjusted risk difference (ARD) 12.33mSv; IQR 10.04, 14.63mSv; p<.001). For a standardized 40 to 49-year-old female, this projects to an additional 0.72 cases of cancer per 1,000. For the entire 2-year perioperative care episode, intraoperative CT as compared to other intraoperative imaging techniques was not found to increase total ionizing radiation exposure (ARD 9.49mSv; IQR -0.83, 19.81mSv; p=.072). The effect of intraoperative imaging choice was mitigated in part due to preoperative (ARD 13.1mSv, p<.001) and postoperative CTs (ARD 22.7mSv, p<.001). CONCLUSIONSPreference-sensitive imaging decisions in the treatment of IS impart substantial cancer risk. Important drivers of radiation exposure exist in each phase of care, including intraoperative CT and/or CT scans during the perioperative period. Knowledge of these data warrant re-evaluation of current imaging protocols and suggest a need for the development of radiation-sensitive approaches to perioperative imaging.

The Use of Skin Staples as Fiducial Markers to Confirm Intraoperative Spinal Navigation Registration and Accuracy.

With the advent of intraoperative computed tomography (CT) for image guidance, numerous examples of accurate navigation being applied to cranial and spinal pathology have come to light. For spinal disorders, the utilization of image guidance for the placement of percutaneous spinal instrumentation, complex osteotomies, and minimally invasive approaches are frequently utilized in trauma, degenerative, and oncological pathologies. The use of intraoperative CT for navigation, however, requires a low target registration error that must be verified throughout the procedure to confirm the accuracy of image guidance. To present the use of skin staples as a sterile, economical fiducial marker for minimally invasive spinal procedures requiring intraoperative CT navigation. Staples are applied to the skin prior to obtaining the registration CT scan and maintained throughout the remainder of the surgery to facilitate confirmation of image guidance accuracy. This low-cost, simple, sterile approach provides surface landmarks that allow reliable verification of navigation accuracy during percutaneous spinal procedures using intraoperative CT scan image guidance. The utilization of staples as a fiducial marker represents an economical and easily adaptable technique for ensuring accuracy of image guidance with intraoperative CT navigation.

Complications Following Orbital Floor Repair: Impact of Intraoperative Computed Tomography Scan and Implant Material.

Importance: Orbital floor fracture repair is complex and postoperative complications are common. A variety of applicable surgical techniques and technologies are available to surgeons, so data about which of these may decrease postoperative complication rates can help better guide clinical decision making. Objectives: To characterize the patient demographics and surgical techniques utilized in orbital floor fracture repairs at San Antonio Military Medical Center and their relationship with rates of postoperative complications. Design, Setting, and Participants: Retrospective chart review of patients who underwent orbital floor fracture repairs from March 2014 to March 2019 with a mean follow-up time of 1.86 months at a tertiary care academic military hospital and level 1 trauma center. Main Outcomes and Measures: Demographic data, indication for surgical repair, fracture severity, orbital floor approach, implant material, and use of intraoperative computed tomography (CT) scan were recorded. Chi-square analysis was performed to determine the relationship between these factors and postoperative diplopia, hypoglobus, enophthalmos, and infection. Results: A total of 124 procedures were performed during the study period: 71.8% of patients were male and 74% were civilian. Mean age was 39 years (range 19-81). Thirty-one patients were lost to follow-up. The most common approach was transconjunctival (83%), which was most frequently used exclusively (68.5%), but was also combined with cantholysis, transcaruncular, or transantral approach. Postoperative diplopia at follow-up was common (53.8%), resolved after an average of 36.3 days, and was significantly associated with surgical indication of entrapment or revision (p = 0.01) and nonutilization of intraoperative CT (p = 0.04). From 2014 to 2016, intraoperative CT was utilized in 21% of cases and revision rate was 10.5%. From 2017 to 2019, 50% of cases utilized intraoperative CT and revision rate was 2% (p = 0.15). Three cases were revisions performed for abnormal plate position noted on postoperative CT scan. Conclusions and Relevance: A statistically significant association was found between postoperative diplopia, surgical indication of entrapment or revision, and nonutilization of intraoperative CT. Revision rates decreased when use of intraoperative CT increased. Three revision cases may have been prevented by use of an intraoperative CT scan. Patients with entrapment should be counseled regarding the increased risk of postoperative diplopia.

Intra-operative computed tomography in endovascular aneurysm repair.

The study objective was to evaluate the ability of computed tomography (CT) to identify technical complications intra-operatively during endovascular aneurysm repair (EVAR). Frequency of complications seen by CT and their sequelae was compared with conventional completion angiography. We performed a systematic review that conformed to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. We considered studies reporting on the effectiveness of intra-operative CT during EVAR. Our literature search yielded six studies that met our criteria for inclusion. In general, these showed intra-operative CT to be superior to completion angiogram at detecting intra-operative complications during EVAR. Despite concerns regarding irradiation, the use of intra-operative CT was found to expose patients to an overall lower radiation dose, since post-operative CT angiograms were no longer required. Moreover, no adverse effect on renal function has been demonstrated as a result of the increased intra-operative contrast usage when CT is used. The current body of evidence suggests that intra-operative CT is superior to completion angiography at detecting clinically important EVAR complications and incurs a lower total radiation dose with no added risk of contrast-induced renal impairment. Further research directly comparing the two modalities in the same cohort is required to determine sensitivity for individual complications.

Intraoperative Computed Tomography Scan for Orbital Fracture Reconstruction.

Orbital fractures pose specific challenge in its surgical management. One of the greatest challenges is to obtain satisfactory reconstruction by correct positioning of orbital implant. Intraoperative computed tomography (CT) scan may facilitate this procedure. The aim of this study was to describe the early use of intraoperative CT in orbital fractures repair in our center. The authors assessed the revision types and rates that have occurred with this technique. With the use of pre-surgical planning, optical intraoperative navigation, and intraoperative CT, the impact of intraoperative CT on the management of 5 cases involving a total number of 14 orbital wall fractures were described. There were 6 pure orbital blowout wall fractures reconstructed, involving both medial and inferior wall of the orbit fracturing the transition zone and 8 impure orbital wall fractures in orbitozygomaticomaxillary complex fracture. 4 patients underwent primary and 1 had delayed orbital reconstruction. Intraoperative CT resulted in intraoperative orbital implant revision, following final navigation planning position, in 40% (2/5) of patients or 14% (2/14) of the fractures. In revised cases, both implant repositioning was conducted at posterior ledge of orbit. Intraoperative CT confirmed true to original reconstruction of medial wall, inferior wall and transition zone of the orbit. Two selected cases were illustrated. In conclusion, intraoperative CT allows real-time assessment of fracture reduction and immediate orbital implant revision, especially at posterior ledge. As a result, no postoperative imaging was indicated in any of the patients. Long-term follow-ups for orbital fracture patients managed with intraoperative CT is suggested.

Use of Intraoperative Computed Tomography in Craniomaxillofacial Trauma Surgery

The use of technology to aid in assessment, planning, and management of complex craniomaxillofacial injuries is increasingly common. Preoperative computed tomography (CT) evaluation is considered the standard of care, and intraoperative imaging is becoming increasingly accessible. Limited data exist regarding the implication of intraoperative CT on decision making in the management of all sites of facial fractures. The purposes of this study were to characterize the use of an intraoperative CT scanner for craniomaxillofacial surgery within our institution, to quantify the effect of intraoperative CT on surgical decision making, and to attempt to provide guidance on when to use this technology. This retrospective case series characterizes the use of an intraoperative CT scanner for craniomaxillofacial trauma surgery at a level 1 trauma center in Portland, Oregon, from February 2011 to September 2016. We evaluated the following variables: the number of intraoperative CT scans performed for craniomaxillofacial surgery including the number of scans for each patient, the number of scans for each operative visit, the CT-directed revision rate (overall and for specific preoperative diagnoses), and the indication for imaging. This information was evaluated to provide guidance on appropriate use of an intraoperative scanner. A total of 161 patients were identified to have intraoperative facial CT scans from February 2011 to September 20, 2016, at Legacy Emanuel Medical Center. A total of 212 intraoperative facial CT scans were performed across 168 separate operations. The overall CT-directed revision rate was 28%. CT-directed revision rates for fracture subsites are as follows: orbital, 31%; zygomaticomaxillary complex, 24%; Le Fort I, 8%; Le Fort II and III, 23%; naso-orbital-ethmoidal, 23%; mandible, 13%; and frontal sinus, 0%. No CT-directed revisions were performed during removal of hardware, during placement of craniofacial implants, or in temporomandibular joint replacement surgery. If available, intraoperative CT should be routinely considered in the operative management of orbital fractures and pan-facial fractures, as well as complex zygomaticomaxillary complex, LeFort II and III, and naso-orbital-ethmoidal fractures.Consideration also should be given to the use of intraoperative CT in cases of complex mandible fractures involving severe comminution or the condylar region. Intraoperative CT should not be routinely used for the management of Le Fort I fractures or frontal sinus fractures.

A Qualitative Web-Based Expert Opinion Analysis on the Adoption of Intraoperative CT and Navigation Systems in Spine Surgery

Introduction Intraoperative computed tomography (CT) and navigation systems have several potential uses in instrumented spine surgery and may decrease patient morbidity and complications leading to very significant cost-effectiveness implications. Despite these proposed advantages, its adaptation in centers across Canada, New Zealand, and Australia is not ubiquitous. The goal of this study is to identify facilitators and barriers to the adoption of intraoperative CT and navigation systems technology by spine surgeons. Materials and Methods A web-based survey was designed to explore spine surgeons' perceived advantages and disadvantages of the use of intraoperative CT and navigation systems, the learning curve of the technology, its teaching utility, and surgeon comfort level with the technology. Questions were based on the unified theory of acceptance and use of technology (UTAUT) model, which explores four main constructs that directly determine user acceptance and usage behavior: performance expectancy, effort expectancy, social influence, and facilitating conditions. The survey was distributed to surgeon members of the Canadian, New Zealand, and Australian Spine Societies. Participants were stratified into 2 groups: users and non-users of intra-operative CT and navigation, with a slight variability in questions answered by both groups based on applicability. Results A total of 53 surgeons completed the survey (34 Canadians, 16 New Zealanders, and 4 Australians). Overall, 24 of them are users of an intraoperative CT and navigation systems, and 29 are nonusers. The top three advantages identified by both users and nonusers in order of importance were more accurate screw placement, safer screw placement, and reassurance and confirmation of optimal screw placement. The top two disadvantages identified by both users and nonusers were the expense to purchase and maintain the equipment and the exposure of patient to radiation. The third main concern for nonusers is the time consumption associated with the use of this technology, whereas for surgeons who do use it, a disadvantage was that the use of intraoperative CT and navigation is technician dependent. Another concern revealed by the survey is after intra-operative CT and navigation use is implemented at an institution, surgeons think that the use of this technology may present an increased risk of infection (58.3% of surgeons who use it are concerned about this). Surgeons who have adopted this technology have done so primarily due to its clinical efficacy with screw placement, whereas surgeons who have not adopted intra-operative CT and navigation identify the cost of this technology as a limiting factor. Conclusion Spine surgeons recognize the benefit of using intraoperative CT and navigation systems to improve screw placement accuracy and safety. The cost associated with this new technology is the biggest deterrent to its widespread adoption in spine surgery centers in Canada, New Zealand, and Australia. Cost-benefit analysis evaluating the use of this technology would be useful in helping surgeons and health care centers make informed decisions about whether or not this investment is warranted.

Achieving Adequate Margins in Ameloblastoma Resection: The Role for Intra-Operative Specimen Imaging. Clinical Report and Systematic Review

BackgroundAmeloblastoma is a locally aggressive odontogenic neoplasm. With local recurrence rates reaching 90%, only completeness of excision can facilitate cure. Surgical clearance has widely been based on pre-operative imaging to guide operative excision margins, however use of intra-operative specimen x-ray or frozen-section has been sought to improve clearance rates, and advanced imaging technologies in this role have been proposed. This manuscript aims to quantify the evidence for evaluating intra-operative resection margins and present the current standard in this role.MethodThe current study comprises the first reported comparison of imaging modalities for assessing ameloblastoma margins. A case is presented in which margins are assessed with each of clinical assessment based on preoperative imaging, intra-operative specimen x-ray, intra-operative specimen computed tomography (CT) and definitive histology. Each modality is compared quantitatively. These results are compared to the literature through means of systematic review of current evidence.ResultsA comparative study highlights the role for CT imaging over plain radiography. With no other comparative studies and a paucity of high level evidence establishing a role for intra-operative margin assessment in ameloblastoma in the literature, only level 4 evidence supporting the use of frozen section and specimen x-ray, and only one level 4 study assesses intra-operative CT.ConclusionThe current study suggests that intra-operative specimen CT offers an improvement over existing techniques in this role. While establishing a gold-standard will require higher level comparative studies, the use of intra-operative CT can facilitate accurate single-stage resection.

Pediatric Pedicle Screw Placement Using Intraoperative Computed Tomography and 3-Dimensional Image-Guided Navigation

A retrospective cohort study reporting the use of intraoperative computed tomography (CT) and image-guided navigation system for the placement of pedicle screws in pediatric compared with adult patients. To evaluate the accuracy of open pedicle screw placement in pediatric patients using intraoperative CT and 3-dimensional (3D) image-guided navigation. Pedicle screws are widely used in children for the correction of spinal deformity. Navigation systems and intraoperative CT are now available as an adjunct to fluoroscopy and anatomic techniques for placing pedicle screws and verifying screw position. From 2007 to 2010, 984 pedicle screws were placed in a consecutive series cohort of 50 pediatric patients for spinal deformity correction with the use of intraoperative CT (O-arm, Medtronic, Inc, Louisville, CO) and a computerized navigation system (Stealth, Medtronic, Inc, Louisville, CO). The primary outcome measure for this study is redirection or removal of screw on the basis of the intraoperative CT imaging. During the study period, 1511 screws were placed in adult patients using the same image guidance system. A total of 984 pedicle screws were implanted using real-time navigation, with a mean of 20 screws per patient (range: 2-34). On the basis of intraoperative CT, 35 screws (3.6%) were revised (27 redirected and 8 removed), representing a 96.4% accuracy rate. No patients returned to the operating room because of screw malposition.Of the 1511 screws placed in adult patients, 28 (1.8%) were revised intraoperatively for malposition on CT imaging, for an overall 98.2% accuracy rate. Screw revision thus was more common in the pediatric population (P = 0.008). However, the pediatric screw accuracy rate is significantly higher than the findings from a recent meta-analysis of predominantly nonnavigated screws in children, reporting a 94.9% accuracy rate (P = 0.03). We report 96.4% accuracy in pediatric pedicle screw placement using intraoperative CT and a 3D navigation system. This is similar to other reports and has better accuracy than a recent meta-analysis of nonnavigated screws in children.