Postoperative CT Research Articles

Recanalization Does Not Always Equate to Reperfusion: No-Reflow Phenomenon After Successful Thrombectomy.

Thrombectomy for acute large vessel occlusion is a well-established treatment for stroke prevention. However, futile recanalization cases, where no-reflow occurs despite successful recanalization, have been reported. This study aimed to assess cerebral hemodynamics immediately after thrombectomy and their relationship with clinical outcomes. We prospectively enrolled patients who underwent successful thrombectomy (modified Thrombolysis in Cerebral Infarction [TICI] ≥2b) for internal carotid artery or middle cerebral artery occlusions at Nagasaki University Hospital between January 2021 and December 2023. Preoperative magnetic resonance imaging was performed, followed by flat-panel computed tomography perfusion 30 minutes after recanalization. Areas with cerebral blood flow <45%, Tmax >6 seconds, and cerebral blood volume <34%, 38%, and 42% were analyzed, and hypoperfusion intensity ratio and cerebral blood volume index were calculated using Rapid ANGIO. We assessed the correlation of these parameters with infarct expansion, hemorrhagic transformation, and poor outcomes, defined as modified Rankin Scale scores of 4 to 6, at 3 months. A total of 65 cases were analyzed. Infarct expansion, defined as a decrease in Alberta Stroke Program Early CT Score, occurred in 23 cases (12/28 TICI 2b and 11/37 TICI 2c/3). No-reflow, defined as Tmax >6 seconds, was observed in 80% of cases (52/65), regardless of TICI grade. The infarct expansion group in TICI 2b had a significantly larger residual cerebral blood flow <45% area (32.9±30.4 versus 10.6±14.5 mL) and a lower cerebral blood volume index (0.71±0.2 versus 0.92±0.2). Cerebral blood flow <45% (r=-0.57; P<0.001) and cerebral blood volume <34% (r=-0.40; P=0.001), not Tmax >6 seconds, negatively correlated with postoperative Alberta Stroke Program Early CT Score. In logistic regression analysis, cerebral blood flow <45% was an independent predictor of poor outcomes (adjusted odds ratio, 1.05 [95% CI, 1.00-1.11]; P=0.039). No-reflow is common after thrombectomy, suggesting that successful recanalization does not always result in immediate tissue reperfusion. Hemodynamic impairment postthrombectomy may persist, highlighting the need for adjunctive treatments.

Changes in the position of the inferior alveolar nerve after sagittal split ramus osteotomy and its effect on postoperative neurosensory disturbances

Aim of the studyTo analyze the positional changes of the inferior alveolar nerve after sagittal split ramus osteotomy (SSRO) and assess the impact of these changes on postoperative sensory nerve disturbances. Material and methodsPreoperative and postoperative (one year) spiral CT scans were used to categorize the inferior alveolar nerve into the extended side (n = 30) and retrogressive side (n = 30). Measurement software was used to observe and measure positional changes of the mandibular nerve canal, followed by a comparative analysis. ResultsPost-surgical analysis revealed that the inferior alveolar nerve was displaced laterally and superiorly on the extended side, and medially and inferiorly on the retrogressive side, with statistically significant differences (p<0.05). Correlation analysis demonstrated a significant association between nerve displacement in the first molar region and sensory nerve impairment (p<0.05). ConclusionSignificant positional changes in the inferior alveolar nerve were observed post-surgery, particularly on the extended migration side, with these changes being correlated with the occurrence of neurological symptoms.

Ankle fractures reduction under direct visualization. Superiority of anatomical landmarks versus radiological evaluation- A randomised control trial.

Distal tibiofibular joint injury is quite common in rotational ankle fractures, with high malreduction rates reported. Although several intraoperative techniques evaluate the optimal tibiofibular reduction, they are critically debated due to high error rates and subjective interpretation of the results. We attempted to describe specific anatomical landmarks and anatomical relationships of the ankle joint through capsulotomy and inspection of the anterior incisura fibularis corner and evaluate their reliability regarding optimal tibiofibular reduction. Sixty patients with malleolar fractures and concomitant distal tibiofibular joint disruption were randomized into two groups. Patients of Group A were treated with a standard approach. In Group B, the reduction was performed following specific anatomical landmarks of the anterolateral ankle joint through capsulotomy. Reduction quality was evaluated with postoperative bilateral ankle CT. Distal tibiofibular joint reduction after direct visualization resulted in significantly better rotation and fibula length values than patients treated with the standard approach. In addition, clinical scores were better in the 3rd and 6th postoperative months.Direct visualization of the anterolateral ankle joint can provide trustworthy anatomical landmarks to achieve high-quality reduction of the distal tibiofibular joint in ankle fractures. Additional repair of the ligamentocapsular structures of the corner enhances joint stability and provides better clinical outcomes in 12 months.

CT-based radiomics predicts adjacent vertebral fracture after percutaneous vertebral augmentation.

Adjacent vertebral fracture (AVF) is a frequent complication following percutaneous vertebral augmentation (PVA). While radiomics is widely utilized in the field of spinal medicine, its application for assessing the risk of AVF in post-PVA patients remains limited. We aim to develop and validate predictive models using machine learning algorithms for radiomics and clinical risk factors to assess the risk of AVF after PVA. This retrospective study included 158 patients with osteoporotic vertebral compression fractures who underwent PVA at our hospital, of which 48 patients had AVF within 2years. The patients were divided into train and test cohorts in a ratio of 7:3. Radiomics features of the surgically intervened vertebrae were extracted from CT images, and selected using Mann-Whitney U-test and LASSO regression to construct a radiomic signature. Machine learning algorithms (SVM and LR) were then employed to integrate the radiomics signature with clinical data to develop predictive models. The performance of the model was assessed using Receiver Operating Characteristic (ROC) curves and calibration curves. Nine optimal radiomics features were selected to form the radiomics model, while five clinical features were identified for the clinical model. The AUCs of the radiomics, clinical, and combined models developed using the SVM algorithm were 0.77, 0.77, and 0.83 on the test cohort, and those of the LR algorithm were 0.78, 0.81, and 0.86. Radiomics and machine learning modeling using postoperative CT images demonstrate noteworthy capability in assessing the risk of AVF following PVA.

Comparison between robot-assisted and navigation-guided minimally invasive transforaminal lumbar interbody fusion: a multicenter study.

Both robot and computer navigation have significantly improved the accuracy and safety of percutaneous pedicle screw placement compared with a freehand fluoroscopy-guided technique. However, how the two new technologies compare with each other is unknown. The aim of this study was to investigate the accuracy and safety of robot-assisted and navigation-guided percutaneous pedicle screw placement in minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF). A multicenter, retrospective study was conducted with patients who underwent 1- to 3-level MIS-TLIF from 2019 to 2022. The surgical indication was symptomatic spinal stenosis and spondylolisthesis that failed conservative management. Screw accuracy and safety were compared between robot and computer navigation systems by obtaining postoperative CT images in all patients. The screw accuracy was determined by the Gertzbein and Robbins classification. A total of 100 patients were divided into robot-assisted (RA; n = 42) and O-arm navigation (ON; n = 58) groups, with 514 percutaneous pedicle screws placed. Clinically satisfactory accuracy was achieved in 100% of the RA group and 92.1% of the ON group (p < 0.001). There were no medial breaches or revision surgeries for screw malposition in either group. The RA group showed similar overall operation time to the ON group (263.54 ± 114.33 vs 243.4 ± 68.96 minutes, p = 0.2821). Subgroup analyses showed that there was no difference in 1-level MIS-TLIF, but the RA group had significantly more operative time for 2-level MIS-TLIF than the ON group (324.67 ± 101.25 vs 266.4 ± 66.38 minutes, p = 0.0264). Screw accuracy was significantly better in the RA group, with slightly more operation time, compared with the navigation group. Neither group required revision surgery or reoperation for screw malposition.

Neuro-oncology application of next-generation, optically tracked robotic stereotaxis with intraoperative computed tomography: a pilot experience.

Innovations in robotics continue to reshape the landscape of neurosurgery. Here, the authors evaluated the safety and efficacy of the ExcelsiusGPS robot in the treatment of neuro-oncological, intracranial lesions. The authors conducted a retrospective analysis of 19 consecutive adult patients with a neuro-oncological diagnosis who underwent intracranial biopsy and/or laser interstitial thermal therapy (LITT) with the assistance of the ExcelsiusGPS robot and intraoperative CT. Demographic and clinical data were collected from the electronic medical record and the robot software. All 19 patients harbored lesions that were deep seated, involving the eloquent cortex, or subcentimeter. Definitive tissue diagnosis was achieved in all cases involving stereotactic biopsy (n = 16), with glioblastoma as the most common diagnosis. The mean ± SD time for setting up the robotic stereotaxis system was 57.4 ± 10.7 minutes. The mean procedural time after that was 71.6 ± 41.0 minutes for stereotactic needle biopsy and 188.4 ± 61.2 minutes for procedures involving LITT. The mean radial errors of the actual trajectory relative to the planned trajectory at the entry and target points were 0.625 ± 0.443 mm and 0.745 ± 0.472 mm, respectively. There were no procedural complications or new postoperative deficits, although routine postoperative CT showed new hyperdensity at the target site in 3/19 patients (15.7%). All patients who underwent elective procedures were discharged by postoperative day 3 (mean 1.38 ± 0.619 days). There were two 30-day readmissions (pulmonary embolus and general weakness), and neither was attributable to the surgical procedure. The authors' pilot experience with the ExcelsiusGPS robot in neuro-oncology procedures indicates a favorable efficacy and safety profile.

Accuracy of intertrochanteric osteotomy for patients with slipped capital femoral epiphysis operated with 3D printed patient-specific guides

BackgroundSlipped Capital Femoral Epiphysis (SCFE), is one of the most common hip disorders in adolescents, and is treated surgically by performing an Imhäuser osteotomy. The use of 3D printed guides has shown promise in improving the accuracy of the osteotomy. However, misplacement of the guide may limit the improvement. Therefore, the aim of this study was to investigate, postoperatively, the degree of malalignment of 3D printed guides compared to the 3D planning.MethodsPatients who underwent surgery between April 2018 and October 2022 and underwent postoperative CT were included in this study. The preoperative CT was used for 3D planning of surgical treatment using 3D printed patient-specific guides and plates. The positioning error of the femoral head and of the patient-specific guide and plate was quantified by analysing the postoperative CT scans using custom software.ResultsFive SCFE patients were included in the study. Femoral head malalignment improved from 16 to 40 mm preoperatively to 11–17 mm postoperatively. Rotational malalignment improved from 29–63⁰ preoperatively to 15–31⁰ postoperatively. Residual error was mostly attributed to plate malposition, with residual translation in the range of 3–13 mm and rotation of 8–28⁰.ConclusionAlthough the postoperative position improved after surgery with 3D printed surgical guides and plates, there was a residual deviation from the planned position persisted. Further research is recommended to improve the design, accuracy of guide placement and surgery in this anatomically challenging region.

Spinal navigation with AI-driven 3D-reconstruction of fluoroscopy images: an ex-vivo feasibility study

BackgroundWith the increasing number of surgeries utilizing spinal instrumentation, three-dimensional surgical navigation aims to improve the accuracy of implant placement. However, its widespread clinical adaption has been hindered by factors such as high radiation exposure and interference with standard surgical workflows.MethodsX23D is a novel AI-based fluoroscopy reconstruction technique that generates a 3D anatomical model of the spine from only four fluoroscopy images. Based on this technology, we developed a prototype for the surgical navigation of pedicle screws placement of the lumbar spine, visualizing the 3D-reconstructed spine anatomy and the surgical drill position in real-time. An ex-vivo study was conducted to compare the accuracy of the X23D-based navigation approach with fluoroscopy-aided freehand instrumentation. Five board-certified surgeons placed pedicle screws on six human torsi within a realistic surgical environment. Breach rate, site and extent (Gertzbein-Robbins) were evaluated in postoperative CT scans, as well as execution time, radiation dose, and user experience. Specimens, operating side, and surgeon were randomised.ResultsForty-nine pedicle screws (n = 24 × 23D, n = 25 2D-fluoroscopy) were evaluated, with six breaches occurring in the control group, one of which was considered clinically significant (medial breach grade C). Five breaches with one clinically significant breach were observed in the X23D group. Breach rate, execution time for each lumbar level (X23D 167 s vs. control 156 s), radiation dose (X23D 33.26 mGy vs. control 49.5 mGy), and user experience did not reveal significant differences (p > 0.05) between the groups.ConclusionsSpinal navigation using the X23D-based approach shows promise and performs well in a realistic surgical ex-vivo setting. With further refinements, its accuracy is expected to match clinical-grade navigation systems while reducing radiation dose.

Prior information guided deep-learning model for tumor bed segmentation in breast cancer radiotherapy.

Tumor bed (TB) is the residual cavity of resected tumor after surgery. Delineating TB from CT is crucial in generating clinical target volume for radiotherapy. Due to multiple surgical effects and low image contrast, segmenting TB from soft tissue is challenging. In clinical practice, titanium clips were used as marks to guide the searching of TB. However, this information is limited and may cause large error. To provide more prior location information, the tumor regions on both pre-operative and post-operative CTs are both used by the deep learning model in segmenting TB from surrounding tissues. For breast cancer patient after surgery and going to be treated by radiotherapy, it is important to delineate the target volume for treatment planning. In clinical practice, the target volume is usually generated from TB by adding a certain margin. Therefore, it is crucial to identify TB from soft tissue. To facilitate this process, a deep learning model is developed to segment TB from CT with the guidance of prior tumor location. Initially, the tumor contour on the pre-operative CT is delineated by physician for surgical planning purpose. Then this contour is transformed to the post-operative CT via the deformable image registration between paired pre-operative and post-operative CTs. The original and transformed tumor regions are both used as inputs for predicting the possible region of TB by the deep-learning model. Compared to the one without prior tumor contour information, the dice similarity coefficient of the deep-learning model with the prior tumor contour information is improved significantly (0.812 vs. 0.520, P = 0.001). Compared to the traditional gray-level thresholding method, the dice similarity coefficient of the deep-learning model with the prior tumor contour information is improved significantly (0.812 vs.0.633, P = 0.0005). The prior tumor contours on both pre-operative and post-operative CTs provide valuable information in searching for the precise location of TB on post-operative CT. The proposed method provided a feasible way to assist auto-segmentation of TB in treatment planning of radiotherapy after breast-conserving surgery.

SURGICAL RESECTION OF A COMPLEX TUBERCULUM SELLAE MENINGIOMA ENCASING MAJOR ARTERIES

Introduction Though constituting only a minor proportion (1%) of sellar masses, suprasellar meningiomas pose a significant diagnostic challenge within the region of sellar and suprasellar tumors. Pituitary adenomas, at nearly 90% prevalence, dominate this anatomical region. Distinguishing these two entities is paramount, as both clinical presentation and, to some extent, biochemical profiles exhibit notable overlap. Accurate preoperative differentiation is critical due to the contrasting behaviors of these tumors. Meningiomas, with their robust vascularity supplied by dural and osseous arteries, present a heightened risk of intraoperative hemorrhage. Clinical Case A 53-year-old woman presented with a two-month history of worsening headaches and gradual vision loss. Neurological examination revealed only visual acuity decline. Her hormone profile showed elevated prolactin but lacked clinical features of prolactin excess, suggesting a possible prolactin-secreting pituitary macroadenoma. A contrast-enhanced MRI confirmed a significant sellar and suprasellar mass with homogeneous enhancement, extending to the right paramedian region and encasing the right internal carotid artery (ICA) at its critical segment involving the cavernous and supraclinoid portions. Furthermore, the right middle meningeal artery (M1) and anterior cerebral artery (A1) originated from this same location, highlighting the high surgical risk. Surgical resection was deemed necessary. The patient underwent a right pterional craniotomy, revealing a grayish, extradural soft mass lesion encasing the ICA bifurcation. Careful microsurgical dissection with basal devascularization was performed, followed by near-complete tumor removal using an ultrasonic aspirator to minimize damage to the encased arteries. Postoperative follow-up CT scan confirmed successful near-total tumor ablation. Conclusion This case underscores the critical role of meticulous preoperative diagnosis in managing complex sellar tumors. While pituitary adenomas dominate this region, suprasellar meningiomas, despite their rarity, demand a high index of suspicion. Overlapping clinical and biochemical presentations highlight the reliance on advanced imaging for accurate differentiation. The intricate vascularity of meningiomas, as exemplified by the encasement of critical arteries in this case, necessitates meticulous surgical technique with devascularization strategies. This successful near-complete tumor removal emphasizes the importance of such surgical expertise in navigating these diagnostically challenging sellar lesions.

Modified reconstruction procedure in subtotal esophagectomy with retrosternal gastric pull up to reduce anastomotic leakage: a propensity score-matched analysis.

One risk factor for anastomotic leakage (AL) after esophagectomy with retrosternal gastric reconstruction is excessive compression of the gastric tube at the thoracic inlet. In this study, we evaluated the effect of our modified procedure to reduce AL by placing the esophagogastric anastomosis below the thoracic inlet. Between January 2008 and December 2022, 174 consecutive patients underwent subtotal esophagectomy with retrosternal gastric pull up, followed by circular stapler anastomosis in our hospitals. After January 2016, the gastric tube was pulled down to place the anastomosis below the suprasternal notch. Postoperative CT then measured the level of esophagogastric anastomosis (LEA). Comparing cases before and after revision (conventional group, n = 65 vs. test group, n = 109), AL was significantly reduced from 11 (16.9%) to 3 (2.8%) cases (P = 0.002). After propensity score matching, AL was observed in 14% (8/57) and 0% (0/57) cases in the conventional and test groups, respectively (P = 0.006). Smaller circular stapler size (P < 0.001), less intraoperative blood loss (P < 0.001), and lower LEA (P < 0.001) were observed in the test group than in the conventional group. Multivariate analysis revealed that anastomotic procedure (OR [95%CI], 0.01[0.00-0.46], P = 0.008), and body mass index (OR [95%CI], 6.92[1.10-135.01], P = 0.038) were the independent risk factors for the development of AL. Our modified procedure to avoid compression of the gastric tube at the thoracic inlet is suggested to noninvasively reduce the risk of AL in the subtotal esophagectomy with retrosternal reconstruction.

CT Surveillance for Local Recurrence After Pancreatic Cancer Resection: Evaluation of Imaging Findings From the SAR Disease-Focused Panel Consensus Statement.

BACKGROUND. A Society of Abdominal Radiology (SAR) Pancreatic Ductal Adeno-carcinoma (PDAC) Disease-Focused Panel (DFP) consensus statement described findings suspicious for local recurrence (LR) on surveillance imaging after PDAC resection. OBJECTIVE. The purpose of this study was to evaluate interreader agreement and predictive utility of potential imaging findings of LR on serial surveillance CT examinations after the Whipple procedure for PDAC, using the SAR PDAC DFP consensus statement. METHODS. This retrospective study included 126 patients (mean age, 68.5 ± 10.3 [SD] years; 72 men, 54 women) who underwent the Whipple procedure for PDAC between January 2009 and December 2014. Three radiologists independently reviewed baseline and subsequent postoperative contrast-enhanced abdominopelvic CT examinations performed within 2 years after surgery, evaluating features in the SAR PDAC DFP consensus statement relating to surgical bed stranding, surgical bed soft tissue, vessel encasement, main pancreatic duct dilatation, and ascites. Interreader agreement was calculated. The reference standard for LR development within 2 years after surgery incorporated all available information. The frequencies of imaging features were calculated for the recurrence examinations (i.e., the first surveillance examinations indicating LR). For baseline postoperative examinations, associations of the imaging features with eventual LR development were assessed by multivariable logistic regression analysis. RESULTS. LR developed within 2 years after surgery in 81 of the 126 patients. For both the baseline and subsequent examinations, agreement for stranding and agreement for soft-tissue morphology were poor, for vessel encasement was fair, for soft tissue and ascites were moderate, and for main pancreatic duct dilatation was substantial. On recurrence examinations, across readers, new or increased stranding was present in 27-77%; new or increased soft tissue, 80-88%; soft tissue with vessel encasement and luminal narrowing, 36-59%; new or increased main pancreatic duct dilatation, 25-26%; and new or increased ascites, 20-23%. On baseline postoperative examinations, independent predictors of eventual LR were soft tissue for all three readers (OR = 2.78-6.85) and stranding for reader 1 (OR = 3.59); main pancreatic duct dilatation and ascites were not independent predictors of LR for any reader. CONCLUSION. This study highlights the role of soft tissue, particularly when associated with vessel encasement and luminal narrowing, in raising suspicion for LR after PDAC resection. CLINICAL IMPACT. This study supports the SAR PDAC DFP consensus statement, while highlighting opportunities for continued optimization.

Life-threatening postoperative hemorrhage caused by lumbar artery injury in asymmetrical pedicle subtraction osteotomy for severe spinal deformity: two case reports.

To present two cases of life-threatening hemorrhage related to lumbar artery injury in adult spinal deformity (ASD) patients following S2‑alar‑iliac (S2AI) fixation and asymmetrical pedicle subtraction osteotomy (PSO), and discuss the possible reasons for postoperative hemorrhage in these patients. Patient A was a 52-year-old female with degenerative lumbar scoliosis who underwent posterior spinal fusion from T8-S2 and one-level PSO at L2. Patient B was a 24-year-old male with severe kyphoscoliosis due to non-ambulatory cerebral palsy, who underwent posterior spinal fusion from T3-S2 and one-level PSO at L1. Both patients underwent asymmetric PSO, where a larger wedge was resected from the convex side of the vertebral body rather than the concave side. Both patients occurred a sudden increase in drainage within 3h postoperatively, who were under anesthesia in AICU. Digital subtraction angiography (DSA) was emergently performed and revealed that the bleeding sites were from the lumbar artery, which was adherent to the convex side of the osteotomized vertebra in both cases. Then successful bleeding control was achieved through vascular embolization. Postoperative CT revealed spike formation at the anterior edges of the open wedge at the PSO level due to sagittal translation (ST), with noticeable derotation of the osteotomized vertebra. For patients with severe kyphoscoliosis, asymmetrical PSO increases the risk of lumbar artery injury on the convex side, and postoperative ST may further contribute to this risk. In cases where a sudden increase in drainage is observed postoperatively, it is crucial to consider the possibility of lumbar artery injury, particularly on the convex side of the osteotomized vertebra.

Atomized inhalation of indocyanine green in thoracoscopic surgery for intralobar pulmonary sequestration: a multicenter study

BackgroundInvestigate the safety and efficacy of preoperative atomization inhalation of indocyanine green (ICG) solution in precise lesion resection of pediatric thoracoscopic intralobar pulmonary sequestration.MethodsA multicenter 1:1 matched case-control study was adopted, to compare the safety and efficacy of the ICG group (preoperative atomization inhalation of 0.5 mg/kg ICG solution) with traditional group (no preoperative atomization inhalation of ICG solution). The baseline, intraoperative, and postoperative recovery conditions of the two groups were observed. Outpatient follow-up visits were conducted 3 to 6 months after surgery, including lung CT scans and pulmonary ventilation function tests.Results134 patients were included in the study. The ICG group included 67 patients, and the traditional surgery group included 67 patients matched at a ratio of 1:1 according to age and lesion location. There were no reports of deaths or adverse reactions. The postoperative chest drainage tube indwelling time [(53.19 ± 8.15) hours vs. (73.25 ± 15.51) hours, P < 0.001] and postoperative hospital stay [(4.81 ± 1.84) days vs. (6.72 ± 1.31) days, P < 0.001] were shorter in the ICG group than in the traditional group. More importantly, the postoperative pulmonary function in the ICG group was better than that in the traditional group. No residual lesions were found in the postoperative CT examination of both groups.ConclusionsThe innovative application of atomization inhalation of ICG provides the possibility for precise localization and lesion resection of pediatric thoracoscopic intralobar pulmonary sequestration. This maximizes the preservation of normal lung parenchyma, better improves postoperative pulmonary function, and shortens postoperative recovery time.

Distance from the midline to the aneurysm as simple predictor of ischemic complication with small unruptured middle cerebral artery aneurysm surgery

BackgroundThis study aimed to clarify the risk factors for postoperative cerebral infarction in surgical clipping for prevalent small middle cerebral artery aneurysms (MCA Ans). MethodsThis retrospective study included 246 patients (mean age, 64.8 ± 10.0 years; 25.6 % males, 74.4 % females) with 258 aneurysms (mean aneurysm size, 5.4 ± 2.4 mm) who underwent direct surgery for unruptured MCA Ans at our institution from January 2015 to December 2020. All surgeries were performed under general anesthesia, incorporating indocyanine green videoangiography and transcranial motor-evoked potentials to enhance surgical precision and safety. The occurrence of surgery-related cerebral infarction was evaluated using postoperative CT scans within one week, comparing them with preoperative images. Patients were categorized based on the presence or absence of postoperative stroke and were analyzed for age, sex, past medical history, aneurysm size, number of clips used, and distance from the midline to the aneurysm. ResultsSeventeen patients had postoperative cerebral infarction (6.6 %, symptomatic 6, asymptomatic 11). There were no significant differences in terms of age, number of clips, or aneurysm size between the two groups; however, the distance from the midline to the aneurysm was significantly shorter in the stroke group (27.1 ± 4.7 mm; p < 0.001), with a cutoff value of 29 mm using the receiver operating characteristic curve. ConclusionSurgical clipping for MCA Ans presents a high risk of cerebral infarction for aneurysms located closer to the midline, emphasizing the importance of considering aneurysm location as a risk indication in surgical clipping.

Robot-assisted technique can achieve accurate screw placement in four-corner fusion and reduce operative difficulty: a cadaver study

BackgroundThe purpose of this study is to explore the feasibility and accuracy of a robot-assisted technique in four-corner fusion compared with traditional freehand operation.MethodsTwenty cadaver specimens were randomly assigned to the robot-assisted group and freehand groups. Three screws were placed percutaneously to fix the capitate-lunate joint, lunate-triquetrum joint, and triquetrum-hamate-capitate joint in each specimen by robot-assisted or freehand technique. The offset between the actual and planned screw positions was determined by merging the images of intraoperative and postoperative CT scans in the robot-assisted group. The centrality of the screw, time-consuming, drilling attempts, and radiation exposure were compared between the two groups.ResultsThe mean offset between the actual and planned screw position was 1.09 (SD: 0.56) mm. The offset at the start point of the screw was significantly lower than that at the endpoint. There was no significant difference in the centrality of the screws, surgical time between the two groups. The number of drilling attempts and the radiation dose received by surgeons were significantly lower in the robot-assisted group.ConclusionsAlthough there was no significant difference in screw centrality between the two groups, the slight offset between the actual and planned screw positions confirmed the feasibility of the robot-assisted technique in four-corner fusion. The robot-assisted technique has advantages in reducing the difficulty of surgery and protecting the surgeon from exposure to large doses of radiation.

Entry point and screw path study of second sacral alar-iliac screw trajectory in spinal pelvic fixation under O-arm navigation

Objective: To explore the feasibility of using the entry point and screw path parameters of sacroiliac (S2AI) screws inserted under O-arm 3D computer navigation as a reference for freehand screw insertion in patients with degenerative spinal deformities. Methods: A retrospective analysis was conducted on the clinical data of 66 patients with degenerative spinal deformities who received S2AI screw fixation assisted by the O-arm 3D computer navigation system at Nanjing Drum Tower Hospital Affiliated with Nanjing University Medical School from January 2017 to April 2022. The patients included 6 males and 60 females, with a mean age of (64.3±5.9) years. Preoperatively, the entry point was set as the intersection of 1 mm from the outer and lower edges of the S1 foramen, adjusted intraoperatively by navigation, and verified postoperatively by full spinal CT scans and 3D reconstructions. Using the S1 screw entry point as the origin, the position of the bilateral S2AI screw entry points, tailward angulation (SA), outward angulation (TA), and vertical distance from the entry point to the skin (SD) were measured on postoperative CT 3D images. The accuracy of S2AI screw placement and any intraoperative and postoperative complications were recorded. Differences in entry point coordinates and screw path parameters between the left and right sides were compared. The intraclass correlation coefficient (ICC) was used to assess intra-observer and inter-observer agreement. Results: The coordinates and screw path parameters for the S2AI screws placed using the O-arm navigation demonstrated good intra-observer and inter-observer consistency (ICC>0.75). The left entry point was located (8.08±1.39) mm laterally and (24.47±2.20) mm caudally from the S1 entry point, while the right entry point was (8.09±1.41) mm laterally and (24.40±2.54) mm caudally, with no significant difference between the left and right sides (both P>0.05). The left TA was 46.33°±3.44°, SA was 39.14°±6.12°, and SD was (60.38±13.37) mm; the right TA was 46.37°±3.41°, SA was 39.59°±5.89°, and SD was (60.30±12.24) mm, with no significant differences between the left and right parameters (all P>0.05). There was no significant neurovascular complications intraoperatively or two weeks postoperatively, with a screw insertion accuracy of 97.7% (129/132). Conclusions: In the fixation of the pelvis in degenerative spinal deformities, the use of O-arm navigation-assisted S2AI screw insertion has a high accuracy rate. It is recommended that for freehand screw insertion, the entry point should be located 24 mm caudally and 8 mm laterally from the outer and lower edges of the superior articular process of S1, with an TA of approximately 46° and a SA of approximately 39°.

Gastrointestinal complications and visceral circulation changes after intentional celiac artery embolization during complex endovascular aortic repair

Intentional celiac artery embolization (CAE) is an oft-used strategy to extend proximal or distal seal during complex endovascular aortic repair. Prior reports document a wide range of GI-related complications. However, associated changes in collateral circulation are poorly defined. We sought to report the long-term outcomes and adaptive changes in collateral visceral circulation following CAE during complex endovascular aortic repair. All patients undergoing complex endovascular aortic procedures (EVAR and TEVAR) with CAE at a single-institution over a 12-year period were included. Pre- and post-operative clinical, radiologic, and laboratory data were reviewed to identify mesenteric complications related to CAE and to assess long-term survival and radiologic changes in collateral anatomy. Multivariable logistic regression was used to determine the association between collateral vessel diameter change and mesenteric complications. From 2011 to 2023, 70 patients underwent planned CAE during complex endovascular aortic repair. With regards to mesenteric complications not attributable to the SMA stent, 11.4% had 30-day mesenteric complications, including upper gastrointestinal bleed (UGIB) or perforated ulcer (n=3), cholecystitis (n=2), pancreatitis (n=2) and ischemic hepatitis (n=1). During 31-90 days after CAE, 2 additional patients (2.9%) had UGIB. With regards to 90-day mesenteric complications related to the SMA stent, 4 additional patients (5.7%) had SMA stent complications leading to mesenteric ischemia. On Kaplan-Meier analysis, patients with any 90-day mesenteric complication had significantly lower overall 2-year survival (42.5% vs 75.0%; P=.002). On pre-operative imaging, 20% of patients had variant SMA anatomy with the GDA as the dominant SMA-celiac collateral pathway in 68.6%. Post-operatively, patients without mesenteric complications had a greater increase in the collateral diameter at both SMA and celiac junctions at 1, 3-6, 12, and 24 months with a statistically significant difference in diameter at 1 month compared to patients with complications (median: 16.2% vs -2.1% at celiac, P=.006 and 20.8% vs 7.7% at SMA, P=.021). On adjusted multivariate regression, increase in collateral diameter at the SMA junction on first post-operative CT was significantly protective of 90-day mesenteric complications (OR: 0.93, 95% CI: 0.87-0.96; P=.046). CAE during complex endovascular aortic repair is a useful adjunct to increase seal zone in select patients; however, mesenteric complications occur in 14% of the patients over a 90-day post-operative period and patients with mesenteric complications have a higher long-term all-cause mortality. CAE should be a technique within the toolbox of vascular surgeons for urgent circumstances that do not allow for celiac preservation. Careful selection of candidates for CAE and early postoperative surveillance of collateral pathways may help with prevention and early identification of long-term visceral complications.

Preoperative Immersive Virtual Reality (iVR) Applied to Percutaneous Nephrolithotomy: A Prospective Randomized Clinical Study of Surgical Planning and Clinical Outcomes.

Percutaneous nephrolithotomy (PCNL) is the procedure of choice for the management of complex or large renal stones. A major challenge for the surgeon, however, is the need to assimilate the nearly 2000 static images from a CT scan into a functional mental image to enable surgical planning. Accordingly, we investigated the potential of immersive virtual reality (iVR) to enhance surgical planning and its impact on the outcomes among patients undergoing PCNL. Between 2019-2023, 175 patients undergoing PCNL were pre-operatively randomized into a CT-only group (N=89) or a CT+iVR group (N=86). CT scans were rendered into iVR models that allowed the surgeon not only to visualize and manipulate each patient's relevant anatomy, but also simulate the percutaneous approach to the proposed calyx. Post-operative CT scans were defined as absolute stone-free, <2mm remnants or 2.1-4mm remnants. Pre-operative visualization of the iVR model resulted in a changed calyx of entry in 30% of cases. The CT+iVR group had a significant improvement in absolute stone-free rate (33.70% vs. 20.22%, p=0.043) and overall <4mm remnant rate (62.79% vs. 48.20%, p=0.044). Clavien-Dindo II+IIIa complications were less in the iVR group (3.48% vs. 12.30%, p=0.03). The results were independent of the surgeon's years of PCNL experience. Pre-operative iVR model visualization benefited surgeons and patients alike. From a surgical standpoint, viewing the iVR model resulted in a safer, more effective percutaneous stone removal procedure.

Radiographic Measurements of Pes Planovalgus Do Not Predict Clinical Outcomes in Tarsal Coalition Excision.

Many patients who undergo tarsal coalition excision have persistent postoperative pain. Most studies have utilized cat scan (CT) scan parameters of pes planovalgus and heel valgus but have found this to be an inconsistent predictor of outcomes. Plain radiographic parameters have been less utilized in trying to predict outcomes after coalition excision. Radiographic talonavicular coverage angle correlates with pain in patients with flexible pes planovalgus (PPV) but has not been studied in tarsal coalition population. Furthermore, foot alignment is not understood to change after simple coalition excision. The purpose of this study was to compare plain radiographic parameters, including talonavicular coverage angle, with pain after tarsal coalition excision, as well as compare preoperative and postoperative weight-bearing radiographs. Seventy-seven feet that underwent excision of the tarsal coalition had clinical outcomes and radiographic data collected >1 year postoperatively. Measures of PPV on preoperative and postoperative weight-bearing radiographs and CT scans were evaluated. Patients were an average of 13 years old at excision. Of the total, 65% had calcaneonavicular (CN) coalitions, whereas the remainder had talocalcaneal coalitions. All patients had significant postoperative improvement in clinical outcomes but 34% (13/38) had continued pain at the most recent follow-up, more so in talocalcaneal than CN coalitions (55% vs 26%, P < 0.001). The subset with CN coalitions had more severe preoperative PPV but greater postoperative PPV improvement. Except for a weak correlation between radiographic weight-bearing (anterior-posterior) talus-first metatarsal angle and pain with activity (r = -0.54), there were no other correlations between preoperative radiographic parameters and clinical outcomes. Heel valgus on CT did not correlate with radiographic measurements of PPV or pain. We did not find a correlation of radiographic PPV with persistent pain after tarsal coalition excision. We did find improvement in radiographic PPV in CN coalitions after treatment with simple excision. Heel valgus on CT was not a useful metric for evaluating PPV in the setting of a tarsal coalition. Level III-prognostic study.