The image-guided operating room-Utility and impact on surgeon's performance in the head and neck surgery

On the use of intraoperative 3D-RX C-arm imaging in orthognathic surgery: a prospective non-consecutive case series study

CONTEXT

Segment and osteosynthesis malposition resulting in patients' complaints (mainly about asymmetries) are encountered in orthofacial/orthognathic surgery.

OBJECTIVE, DESIGN, AND SETTING

We planned to investigate the usefulness of intraoperative three-dimensional (3D) imaging concerning positioning and fixation of bone segments and osteosynthesis in orthognathic/orthofacial surgery. We performed a prospective study of non-consecutive cases. All patients receiving a bimaxillary osteotomy, genioplasty, and their combinations were included in the study from May 2016 to May 2020. Unilateral and bilateral sagittal split osteotomies were excluded. There were no gender and age limitations. All were intraoperatively examined using the BV Pulsera 3D-RX System (Philips Medical, Eindhoven, The Netherlands). The outcome variables were the percentage of revisions of segment positioning and osteosynthesis. Predictor variables were age, gender, type of surgery, timing (pre- and post-imaging), and surgeon experience (senior vs assistant).

RESULTS

Forty female and twenty-two male patients were included (mean age 25.25 years ± 7.52 and 29.1 years ± 12.6 respectively). We evaluated 27 genioplasties and 34 Le Fort "type-I" osteotomies. Indications for segment repositioning and redo-osteosynthesis increased after intraoperative imaging as compared to operator's clinical judgment before intraoperative imaging (95% confidence interval; p < .001 and p = .002 respectively).

CONCLUSION

Suboptimal positioning and fixation of bone segments or osteosynthesis were more apparent with 3D imaging. In addition, some satisfactory cases were also revised for an optimal outcome. As a result, surgeons were prompted to more revisions than judged necessary without intraoperative imaging.

Skull-Base Surgery—A Narrative Review on Current Approaches and Future Developments in Surgical Navigation

Surgical navigation technology combines patient imaging studies with intraoperative real-time data to improve surgical precision and patient outcomes. The navigation workflow can also include preoperative planning, which can reliably simulate the intended resection and reconstruction. The advantage of this approach in skull-base surgery is that it guides access into a complex three-dimensional area and orients tumors intraoperatively with regard to critical structures, such as the orbit, carotid artery and brain. This enhances a surgeon’s capabilities to preserve normal anatomy while resecting tumors with adequate margins. The aim of this narrative review is to outline the state of the art and the future directions of surgical navigation in the skull base, focusing on the advantages and pitfalls of this technique. We will also present our group experience in this field, within the frame of the current research trends.

Evaluation of 3-dimensional rotational venography for the diagnosis of non-thrombotic iliac venous lesion

Background

The purpose of this study was to determine the technical feasibility and safety of 3D rotational venography (3D-RV) in the diagnosis of non-thrombotic iliac vein lesions compared with traditional 2D-digital subtraction angiography (2-DSA).

Methods

The general epidemiological data (including age, gender), clinical manifestations (including major symptom, affected extremity, CEAP classification, comorbidity, stenosis rate), and intra-operative findings (iliac vein indentation position, collateral circulation, procedure time, X-rays dose, contrast agent dosage) of 61 NIVL patients who were assessed by 3D-RV and traditional 2-DSA between October 2018 to October 2022 were obtained and analyzed.

Results

A total of 61 consecutive patients with symptomatic NIVL from our institution were enrolled in this study. With the aggravation of iliac vein stenosis, the proportion of indicators such as contralateral formation and iliac vein compression indentation reflecting the severity of compression under 3D-RV reconstruction increased significantly. Also, significant differences were observed between the 3D-RV and 2-DSA groups concerning procedure time (10.56 ± 0.09 s vs. 12.59 ± 0.37 s; p < 0.01), X-ray dose (41.25 ± 0.21 mGy vs. 81.59 ± 1.69 mGy; p < 0.01) and contrast agent dosage (21.48 ± 0.24 mL vs. 33.69 ± 0.72 mL; p < 0.01). Contralateral iliac vein imaging (p = 0.002), pelvic collateral vein imaging (p = 0.03), and external iliac vein indentation (p = 0.001) were found to influence the severity of iliac vein compression.

Conclusion

3D-RV can display dynamic stereo image information of NIVL, augmenting the information obtained from traditional 2-DSA. Contralateral iliac vein imaging, pelvic collateral vein imaging, and external iliac vein indentation can be used to evaluate the severity of iliac vein compression to some extent.

Automatic Registration and Error Color Maps to Improve Accuracy for Navigated Bone Tumor Surgery Using Intraoperative Cone-Beam CT

Computer-assisted surgery (CAS) can improve surgical precision in orthopaedic oncology. Accurate alignment of the patient’s imaging coordinates with the anatomy, known as registration, is one of the most challenging aspects of CAS and can be associated with substantial error. Using intraoperative, on-the-table, cone-beam computed tomography (CBCT), we performed a pilot clinical study to validate a method for automatic intraoperative registration.

Stapes visualization by ultra-high resolution CT in cadaveric heads: A preliminary study

PURPOSE

This study aimed to assess stapes visualization using an ultra-high resolution computed tomography (U-HRCT).

METHOD

Sixty ears from 30 cadaveric human heads were scanned by both U-HRCT and 128-section multislice CT (MSCT) with clinical parameters. Image quality of the stapes head, anterior and posterior crura, footplate, incudostapedial joint and stapedial muscle within the pyramidal eminence was scored using a 3-point Likert scale. Linear measurements of the stapes configuration were performed on U-HRCT.

RESULTS

The interobserver agreement for image qualitative score on U-HRCT was good to excellent (interobserver agreement coefficients 0.65-0.86). With the exception of the stapes head, U-HRCT achieved significantly higher qualitative scores than MSCT across all anatomical structures (Ps < 0.05). The total height of the stapes was measured to be 3.48 ± 0.33 mm. The height and width of the obturator foramen were 1.77 ± 0.28 mm and 2.19 ± 0.33 mm, respectively. The widths of the anterior and posterior crura were 0.20 ± 0.06 mm and 0.22 ± 0.06 mm, respectively. The thickness of the footplate was 0.22 ± 0.06 mm, and the angle of the incudostapedial joint was 95.91 ± 10.69°.

CONCLUSIONS

U-HRCT is capable of delineating fine structures of the stapes and provides linear data on dimensions of the stapes, which could be helpful for detecting stapes disease and making individualized surgical plans in the clinical setting.

Assessment of a liposomal CT/optical contrast agent for image-guided head and neck surgery

This study evaluates a long-acting liposomal fluorescence / CT dual-modality contrast agent (CF800) in head and neck cancer to enhance intraoperative tumor demarcation with fluorescence imaging and cone-beam computed tomography (CBCT). CF800 was administered to 12 buccal cancer-bearing rabbits. Imaging was acquired at regular time points to quantify time-dependent contrast enhancement. Surgery was performed 5-7 days after, with intraoperative near-infrared fluorescence endoscopy and CBCT, followed by histological and ex-vivo fluorescence assessment. Tumor enhancement on CT was significant at 24, 96 and 120 hours. Volumetric analysis of tumor segmentation showed high correlation between CBCT and micro-CT. Fluorescence signal was apparent in both ex-vivo and in-vivo imaging. Histological correlation showed [100%] specificity for primary tumor. Sensitivity and specificity of CF800 in detecting nodal involvement require further investigation.CF800 is long acting and has dual function for CT and fluorescence contrast, making it an excellent candidate for image-guided surgery.

Sentinel lymph node mapping using ICG fluorescence and cone beam CT - a feasibility study in a rabbit model of oral cancer

BACKGROUND

Current sentinel lymph node biopsy (SLNB) techniques, including use of radioisotopes, have disadvantages including the use of a radioactive tracer. Indocyanine green (ICG) based near-infrared (NIR) fluorescence imaging and cone beam CT (CBCT) have advantages for intraoperative use. However, limited literature exists regarding their use in head and neck cancer SLNB.

METHODS

This was a prospective, non-randomized study using a rabbit oral cavity VX2 squamous cell carcinoma model (n = 10) which develops lymph node metastasis. Pre-operatively, images were acquired by MicroCT. During surgery, CBCT and NIR fluorescence imaging of ICG was used to map and guide the SLNB resection.

RESULTS

Intraoperative use of ICG to guide fluorescence resection resulted in identification of all lymph nodes identified by pre-operative CT. CBCT was useful for near real time intraoperative imaging and 3D reconstruction.

CONCLUSIONS

This pre-clinical study further demonstrates the technical feasibility, limitations and advantages of intraoperative NIR-guided ICG imaging for SLN identification as a complementary method during head and neck surgery.

C-arm-based flat-panel detector cone-beam computed tomography venography in the diagnosis of iliac vein compression syndrome

Background:

C-arm-based flat-panel detector cone-beam computed tomography (CBCT) venography has never been used in the management of iliac vein compression syndrome (IVCS). This study aimed to determine the technical feasibility and safety of CBCT venography in the diagnosis of IVCS compared with conventional venography (CV).

Methods:

Twenty patients with clinical manifestations of lower extremity venous insufficiency were prospectively enrolled between May 2018 and December 2018. Each patient underwent both CV and CBCT venography. The feasibility and safety of CBCT venography were assessed by technical success rate and complication rate. The relationships between the clinical indexes and the results of CBCT venography and CV were analyzed with correlation analysis. The consistency of the diagnosis of IVCS using each modality was analyzed by the kappa test.

Results:

The technical success rate was 100% for CBCT venography and for CV, without any complications. Compared with CV, CBCT venography was able to show more details of adjacent tissues which might be helpful for making etiological diagnosis. The stenosis rate under CBCT venography had excellent consistency with that under CV (kappa = 0.78, Chi-square test). The stenosis rate under CBCT venography was positively correlated with the presence of collateral veins (odds ratio 1.12, 95% confidence interval: [1.00, 1.26], P = 0.049), while the stenosis rate under CV was not. Unexpectedly, only one patient had a venous pressure gradient of more than 2 mmHg (1 mmHg = 0.133 kPa).

Conclusions:

For the diagnosis of IVCS, C-arm-based CBCT venography was technically feasible, with good safety. The presence of collateral veins on CBCT was clinically significant. A C-arm fluoroscopy-based technique that combines CV and CBCT might be a promising protocol for the management of IVCS during a single session.