Postoperative Scans Research Articles

Bone wax causing a middle trunk plexopathy following vertebral artery injury: a neuroradiological pitfall

BackgroundBone wax is a hemostatic agent widely used in surgery. Since it is neither absorbed nor metabolized, its use remains risky and a potential cause of complications. Even though its MRI radiological characteristics are distinguishable, it is generally misinterpreted as postoperative hematoma or trapped air. We report the first case in literature of brachial plexopathy due to the compressive mass effect of bone wax and the main clues that led us to establish this diagnosis prior to its surgical resection.Case presentationA 20-year-old male, victim of stabbing presented with an open wound of the right latero-cervical region with a vascular injury of the V2 segment of the right vertebral artery on CT angiography. He was first admitted for bleeding from the neck uncontrollable with external pressure. The patient underwent an emergency surgical vertebral artery ligation. Forty-eight hours later, he reported a feeling of paresthesia of right arm with right-sided weakness. Neurologic examination revealed a motor deficit of the right triceps and wrist extensor muscles and absence of the triceps reflex. A postoperative compression of the C7 cervical root or the middle trunk of brachial plexus was initially suspected. A cervical MRI demonstrated a T1- and T2-weighted images well-defined right mass located laterally to the spinal cord in the epidural space at the level of C6–C7 vertebrae with a signal-intensity void on both sequences. T2*-weighted images showed no signal attenuation. It did not enhance after contrast administration. An epidural hematoma was less probable since acute hematoma is typically hypointense on T2*-weighted images. Computed tomography helped rule out residual postoperative air trapped in the epidural space based on the density study of the mass compared to air. Finally, a residual surgical foreign material used for packing during the procedure was suspected. The massive use of bone wax was ultimately confirmed by the surgeon and surgically removed with complete immediate postoperative recovery.ConclusionsThis case highlights the importance of a nuanced critical approach of neurosurgeons and neuroradiologists when interpreting postoperative neuroimaging scans of the spine. It is crucial to always consider foreign body-related complications and to review the per-operative procedure in details.

Persistent Mullerian duct syndrome: An atypical clinical presentation

Abstract Introduction Persistent Müllerian duct syndrome (PMDS) is a rare sexual development disorder characterized by a normal male phenotype. Müllerian structures cannot regress due to the absence of anti-müllerian hormone (AMH) or resistance to AMH receptor. In addition to male internal genitalia, female reproductive organs, including the uterus, uterine tubes, and upper 1/3 of the vagina are also detected. We will present a patient with PMDS who presented with bilateral cryptorchidism. Clinical Case A 31-year-old single man was referred to our clinic because of bilateral undescended testes and a rudimentary uterus detected during the evaluation of the lower abdominal pain. On physical examination, his body mass index (BMI) was 21.2. His arm span was 170 cm, and his upper-lower segment ratio was 0.96. Beard, axilla, and pubic hair development were normal; however, testes were not in the scrotum bilaterally. His karyotype analysis was 46XY. His prenatal, natal, and postnatal histories were not remarkable. His parents were not consanguineous; the younger brother had a history of undescended testis operation at age one. In laboratory examination, blood glucose, renal and liver functions were normal. Androstenedione, DHEAS, total and free testosterone, FSH, LH, total-hCG, AFP were normal. AMH>9µg/L. In the spermiogram, no sperm was observed. A rudimentary uterus and proximal vagina were observed in the abdominal computed tomography (CT). Symmetric solid masses measuring 55×40 mm compatible with bilateral undescended testis were detected in the ovarian lodges. The mass extended to the inguinal canal on the left and the scrotum on the right. In association with these masses, there were also tubular structures with the biggest diameter of 16 mm on the right and 13 mm on the left. Prostate sizes were normal. Seminal vesicles were not observed. PMDS was considered owing to 46 XY karyotypes, normal testosterone level, normal sexual development, external genitalia findings, accompanying Mullerian structures, and a high level of AMH. AMH gene mutation was not detected. However, AMH receptor type 2(AMHR2) gene mutation could not be studied. Bilateral undescended testicles, uterus, uterine tubes, and the tubular structures in the abdomen were excised. Classical type seminoma with lympho-vascular invasion was detected in the right-side tubular structure. Tumor-negative testicular tissue was frozen for possible fertility in the future. The patient received one cycle of Carboplatin. No metastasis was detected in the post-operative PET-CT scan. In post-operative evaluation, FSH, LH levels were high, total and free testosterone levels were low. AMH < 0.01 µg/L. The patient was started on testosterone replacement therapy. Conclusion PMDS is a rare cause of male pseudo-hermaphroditism. Malignant degeneration and infertility are two critical points in terms of treatment. Early diagnosis with increased awareness is essential in preserving fertility and preventing malignant degeneration.

Overcoming roadblocks in clinical innovation via high fidelity simulation: use of a phantom simulator to achieve FDA and IRB approval of a clinical trial of fetal embolization of vein of Galen malformations

BackgroundVein of Galen malformation (VOGM) is a rare, life-threatening vascular malformation in neonates and is treated with embolization. However, even at the most experienced centers, patients face high mortality and...

Accuracy of a dynamic navigation system for dental implantation with two different workflows and intraoral markers compared to static-guided implant surgery: An in-vitro study.

To investigate the accuracy of a miniaturized dynamic navigation system with intraoral markers and two different workflows for dental implantation and to compare with static computer-assisted implant surgery (sCAIS) surgery. Two operators performed a total of 270 implant insertions in polyurethane mandibular models under simulated clinical conditions. Implants were placed after CBCT-based virtual planning in three different groups: two workflows utilizing dynamic computer-assisted implant surgery (dCAIS; DG1: marker in CBCT; DG2: 3D-printed marker) and the others with sCAIS (TG: template guided). Postoperative surface scans were matched to the planning data and allowed an evaluation of the angular and spatial deviation between the planned and the actually achieved implant position. Descriptive statistics were followed by a Mixed Model Analysis to determine the influence of the operator, the method, and operating area on different accuracy parameters and the random effect of the model number. The mean angular deviation ranged from 2.26° (DG1) to 2.96° (TG). The mean 3D deviation at the implant's tip ranged from 1.08 mm (TG) to 1.51 mm (DG2) and at the implant's base from 0.69 mm (TG) to 1.49 mm (DG2). The operator showed no significant influence on the accuracy. The method showed significant influence on singular parameters and the operating area on all spatial accuracy parameters. Dynamic navigation systems with intraoral markers enable accurate implant positioning, which is comparable to the static-guided implant surgery. 3D-printed markers provide less accurate results compared to prefabricated markers, attached before CBCT scan.

Evolution of Radiographic Changes of a Vascularized Pedicled Nasoseptal Flap after Endonasal Endoscopic Skull Base Surgery.

There is active research involving the radiographic appearance of the skull base following reconstruction. The purpose of this study was to describe the radiographic appearance of the vascularized pedicle nasoseptal flap after endoscopic skull base surgery across time. We performed chart and imaging review of all patients with intraoperative nasoseptal flap placement during endoscopic skull base surgery at a tertiary academic skull base surgery program between July 2018 and March 2021. All patients underwent immediate and delayed (>3 months) postoperative MR imaging. Primary outcome variables included flap and pedicle enhancement, flap thickness, and flap adherence to the skull base. Sixty-eight patients were included. Flap (P = .003) enhancement significantly increased with time. Mean nasoseptal flap thickness on immediate and delayed postoperative scans was 3.8 and 3.9 mm, respectively (P = .181). The nasoseptal flap adhered entirely to the skull base in 37 (54.4%) and 67 (98.5%) patients on immediate and delayed imaging, respectively (P < .001). Our findings demonstrate heterogeneity of the nasoseptal flap appearance after skull base reconstruction. While it is important for surgeons and radiologists to evaluate variations in flap appearance, the absence of enhancement and lack of adherence to the skull base on immediate postoperative imaging do not appear to predict reconstructive success and healing, with many flaps "self-adjusting" with time.

Facet joint violation after open and percutaneous posterior instrumentation: a comparative study

PurposePosterior instrumentation is the state-of-the-art surgical treatment for fractures of the thoracic and lumbar spine. Options for pedicle screw placement comprise open or minimally invasive techniques. Open instrumentation causes large approach related muscle detachment, which minimally invasive techniques aim to reduce. However, concerns of accurate pedicle screw placement are still a matter of debate. Beside neurological complications due to pedicle screw malplacement, also affection of the facet joints and thus motion dependent pain is known as a complication. The aim of this study was to assess accuracy of pedicle screw placement concerning facet joint violation (FJV) after open- and minimally invasive posterior instrumentation.MethodsA retrospective data analysis of postoperative computer tomographic scans of 219 patients (1124 pedicle screws) was conducted. A total of 116 patients underwent open screw insertion (634 screws) and 103 patients underwent minimally invasive, percutaneous screw insertion (490 screws). ResultsIn the lumbar spine (segments L3, L4, L5), there were significantly more and higher grade (open = 0.55 vs. percutaneous = 1.2; p = 0.001) FJV’s after percutaneously compared to openly inserted screws. In the thoracic spine, no significant difference concerning rate and grade of FJV was found (p > 0.56).ConclusionFJV is more likely to occur in percutaneously placed pedicle screws. Additionally, higher grade FJV’s occur after percutaneous instrumentation. However, in the thoracic spine we didn’t find a significant difference between open and percutaneous technique. Our results suggest a precise consideration concerning surgical technique according to the fractured vertebrae in the light of the individual anatomic structures in the preop CT.

3D-Printed Metal Surgical Guide for Endodontic Microsurgery (a Proof of Concept)

Thanks to recent advances, printed surgical guides are now fully integrated into digital workflows and are beneficial in terms of accuracy in endodontic microsurgery (EMS). The aim of this study was to evaluate the accuracy of new 3D-printed surgical metal guides (SMGs) with open-frame structures in an endodontic surgical simulation model ex vivo based on a pig jaw. Twenty-nine roots were included. SMGs were produced using 3D implant planning software and printed using cobalt-chrome and a laser sintering printer. The SMGs were designed to allow for surgical access at 3 mm from the apex of each root. Virtual planning and postoperative CBCT scans were compared by analysing the apical and angular deviations. To test for deviations equal to zero, a one-sample test was used. The differences between the virtually planned implant and the actual position of the drill path were statistically significant for five SMGs on the eight produced guides, whereas there were no differences for the three others. The mean apical deviation was 3.2 mm ± 1.7 using SMGs, and the angular deviation was measured at 3.10 degrees ± 2.37. Although deviations were observed, the results demonstrate the feasibility and the potential for such guides during EMS procedures.

Predicting late aortic complications after acute type A dissection surgery with volumetric measurements in a Singapore cohort.

This study was conducted to evaluate the efficacy of postoperative computed tomography (CT) measurements of aortic lumen volumes in predicting aortic-related complications following acute type A aortic dissection (ATAAD) repair. We conducted a single-institution retrospective aortic volumetric analysis of patients after ascending aorta replacement performed during 2001-2015. The volumetric measurements of total lumen (total-L), true lumen (TL), false lumen (FL), as well as the TL:FL ratio from the first and second postoperative computer angiograms were obtained. A generalised structural equation model was created to analyse the predictive utility of TL:FL ratio. One hundred and twenty-five patients underwent surgical intervention, of whom 97 patients were eventually discharged and analysed for postoperative complications. A total of 19 patients were included in the final analysis. Patients with late postoperative aortic complications had a significantly higher FL volume and total-L volume on the first (FL volume P = 0.041, total-L volume P = 0.05) and second (FL volume P = 0.01, total-L volume P = 0.007) postoperative scans. The odds of having aortic complications were raised by 1% with a 1 cm3 increase in total-L volume and by 2% with a 1 cm3 increase in FL volume. The TL:FL ratio was significantly lower in patients who developed complications. Postoperative CT volumetric measurements in patients who developed complications are characterised by a significant increase in the FL volume and total-L volume from the first postoperative scans. Patients with disproportionately expanded FL presenting with TL:FL ratios less than 1 were associated with aortic complications. Hence, the TL:FL ratio may be a reliable and useful parameter to monitor postoperative disease progression and to evaluate the risk of late complications in ATAAD patients.

Automatic detection and segmentation of postoperative cerebellar damage based on normalization.

Surgical resection is the gold standard in the treatment of pediatric posterior fossa tumors. However, surgical damage is often unavoidable and its association with postoperative complications is not well understood. A reliable localization and measure of cerebellar damage is fundamental to study the relationship between the damaged cerebellar regions and postoperative neurological outcomes. Existing cerebellum normalization methods are likely to fail on postoperative scans, therefore current approaches to measure postoperative damage rely on manual labelling. In this work, we develop a robust algorithm to automatically detect and measure cerebellum damage in postoperative 3D T1 magnetic resonance imaging (MRI). In our approach, normal brain tissues are first segmented using a Bayesian algorithm customized for postoperative scans. Next, the cerebellum is isolated by nonlinear registration of a whole-brain template to the native space. The isolated cerebellum is then normalized into the spatially unbiased atlas (SUIT) space using anatomical information derived from the previous step. Finally, the damage is detected in the atlas space by comparing the normalized cerebellum and the SUIT template. We evaluated our damage detection tool on postoperative scans of 153 patients with medulloblastoma based on inspection by human experts. We also designed a simulation to evaluate performance without human intervention and with an explicitly controlled and defined ground truth. Our results show that the approach performs adequately under various realistic conditions. We develop an accurate, robust, and fully automatic localization and measurement of cerebellar damage in the atlas space using postoperative MRI.

The impact of temporal lobe epilepsy surgery on picture naming and its relationship to network metric change

BackgroundAnterior temporal lobe resection (ATLR) is a successful treatment for medically-refractory temporal lobe epilepsy (TLE). In the language-dominant hemisphere, 30%- 50% of individuals experience a naming decline which can impact upon daily life. Measures of structural networks are associated with language performance pre-operatively. It is unclear if analysis of network measures may predict post-operative decline. MethodsWhite matter fibre tractography was performed on preoperative diffusion MRI of 44 left lateralised and left resection individuals with TLE to reconstruct the preoperative structural network. Resection masks, drawn on co-registered pre- and post-operative T1-weighted MRI scans, were used as exclusion regions on pre-operative tractography to estimate the post-operative network. Changes in graph theory metrics, cortical strength, betweenness centrality, and clustering coefficient were generated by comparing the estimated pre- and post-operative networks. These were thresholded based on the presence of the connection in each patient, ranging from 75% to 100% in steps of 5%. The average graph theory metric across thresholds was taken.We incorporated leave-one-out cross-validation with smoothly clipped absolute deviation (SCAD) least absolute shrinkage and selection operator (LASSO) feature selection and a support vector classifier to assess graph theory metrics on picture naming decline. Picture naming was assessed via the Graded Naming Test preoperatively and at 3 and 12 months post-operatively and the outcome was classified using the reliable change index (RCI) to identify clinically significant decline. The best feature combination and model was selected using the area under the curve (AUC). The sensitivity, specificity and F1-score were also reported. Permutation testing was performed to assess the machine learning model and selected regions difference significance. ResultsA combination of clinical and graph theory metrics were able to classify outcome of picture naming at 3 months with an AUC of 0.84. At 12 months, change in strength to cortical regions was best able to correctly classify outcome with an AUC of 0.86. Longitudinal analysis revealed that betweenness centrality was the best metric to identify patients who declined at 3 months, who will then continue to experience decline from 3 to 12 months. Both models were significantly higher AUC values than a random classifier. ConclusionOur results suggest that inferred changes of network integrity were able to correctly classify picture naming decline after ATLR. These measures may be used to prospectively to identify patients who are at risk of picture naming decline after surgery and could potentially be utilised to assist tailoring the resection in order to prevent this decline.

Comparative evaluation of the effect of conventional and truss access cavities on remaining dentin thickness, canal transportation, and canal centering ability in mandibular molars using cone-beam computed tomography

Aim: To evaluate and compare the effect of conventional and truss access cavity preparations on remaining dentin thickness (RDT), canal transportation, and centering ability in mandibular molars using cone-beam computed tomography (CBCT). Methods: Ethical approval was obtained before the commencement of the study. Thirty extracted mandibular molars were selected, disinfected, and stored in normal saline. Preoperative CBCT scans were taken for all the samples and randomly divided into two groups. (n = 15). Group A; Conventional access preparation group; Group B; Truss access preparation group. Cleaning and shaping were performed with the mesiobuccal canal of all the samples. Postoperative CBCT scans were compared with preoperative CBCT scans to evaluate the RDT, canal transportation, and canal centering ability in mandibular molar with conventional and truss access cavity preparation. Results: Data obtained from CBCT were analyzed by independent sample t-test with the P < 0.05 and found that RDT was higher in Group A as compared to Group B at the 3 and 9 mm levels, whereas it was higher in Group B at 6 mm level in both the mesial and distal side, but it was statistically insignificant at 3, 6, and 9 mm level. Canal transportation was higher in Group B than in Group A, but it was statistically insignificant at 6 and 9 mm levels but statistically significant at 3 mm. Canal centering ability was higher in Group A than in Group B, but it was not statistically significant at 3, 6, and 9 mm levels. Conclusion: Regarding RDT and canal centering ability, there is no statistically significant difference at all levels. Both groups present a statistically significant difference at 3 mm from the apex when comparing canal transportation. This suggests that conventional access cavity preparation is better than truss access preparation to maintain original canal anatomy.

PS-R03-10: CASE REPORT: CUSHING SYNDROME IN A YOUNG MALE

A 27-year-old male without any significant past medical history was advised to visit a hospital for elevated blood pressure, elevated liver enzymes, and dyslipidemia in a workplace health checkup. His body weight had increased by more than 10 kg in the last two years. He presented to our department and underwent laboratory work-up. He had bilateral lower limb pitting edema, hypokalemia, and elevation of low-density lipoprotein. No sign of dysthyroidism, renin-angiotensin-aldosterone system disorder, or increased catecholamine secretion was found. Diet and exercise therapy and calcium channel blocker did not improve his hypertension, and he suffered from lumber vertebral fracture, refractory hypokalemia, and lower leg cellulitis. He was admitted to our department for detailed examination of worsening lower limb edema. On admission, he had striae on his abdomen and legs as well as edema of both lower extremities. The endocrinological data showed high levels of adrenocorticotropic hormone (ACTH) and cortisol. Overnight 1 mg dexamethasone suppression test resulted in a non-suppression response, and his circadian rhythm of cortisol was absent. Urine cortisol level was high. These findings confirmed the diagnosis of ACTH-dependent Cushing syndrome. A contrasted magnetic resonance imaging (MRI) scan demonstrated enlargement of the pituitary gland more than 1 cm in length. Taking into account drug-resistant hypokalemia and vulnerability to infection, he was administered with metyrapone 500 mg per day until he underwent transsphenoidal hypophysectomy. The pathological findings were consistent with that of a pituitary adenoma. Postoperative MRI scan showed remnant lesions which stretch to the bilateral cavernous sinuses and the right middle cranial fossa. Although a decrease in urine cortisol was observed, the absence of a circadian rhythm of cortisol, hypertension, and hypokalemia persisted. He is now treated with somatostatin analog and craniotomy followed by gamma knife surgery is planned. Cushing syndrome should be suspected in cases of early-onset hypertension with symptoms including weight gain, hypokalemia, and bone fracture.

Accuracy of zygomatic dental implant placement using computer-aided static and dynamic navigation systems compared with a mixed reality appliance. An in vitro study.

Analyze and compare the accuracy of zygomatic dental implant placement carried out using a static navigation surgery, a dynamic navigation surgery and an augmented reality appliance. Eighty (80) zygomatic dental implants were randomly assigned to one of four study groups: A: static navigation implant surgery (n = 20) (GI); B: dynamic navigation implant surgery (n = 20) (NI); C: augmented reality appliance implant placement (n = 20) (ARI) and D: free hand technique (n = 20) (FHI). A preoperative cone-beam computed tomography (CBCT) scan of the existing situation was performed to plan the surgical approach for the computer assisted implant surgery study groups. Four zygomatic dental implants were placed in anatomical-based polyurethane models (n = 20) manufactured by stereolithography, and a postoperative CBCT scan was taken. Subsequently, the preoperative planning and postoperative CBCT scans were uploaded to dental implant software to analyze the coronal global, apical global, and angular deviations. Results were analyzed using linear regression models with repeated measures to assess the differences according to the group, according to the position, and the interaction between both variables. If statistically significant differences were detected, 2-to-2 comparisons were made between the groups/positions. The results did not show statistically significant differences between the coronal global deviations of GI (5.54 ± 1.72 mm), NI (5.43 ± 2.13 mm), ARI (5.64 ± 1.11 mm) and FHI (4.75 ± 1.58 mm). However, showed statistically significant differences between the apical global deviations of FHI (3.20 ± 1.45 mm) and NI (4.92 ± 1.89 mm) (p = 0.0078), FHI and GI (5.33 ± 2.14 mm) (p = 0.0005) and FHI and ARI (4.88 ± 1.54 mm) (p = 0.0132). In addition, the results showed also statistically significant differences between the angular deviations of FHI (8.47º ± 4.40º) and NI (7.36º ± 4.12º) (p = 0.0086) and between GI (5.30º ± 2.80º) and ARI (9.60º ± 4.25º) (p = 0.0005). Free-hand technique provides greater accuracy of zygomatic dental implant placement than computer-assisted implant surgical techniques, and zygomatic dental implants placed in the anterior region are more accurate than in the posterior region. However, it is an in vitro study and further clinical studies must be conducted to extrapolate the results to the clinical setting. Key words:Implantology, computer assisted implant surgery, image-guided surgery, augmented reality, navigation surgery, zygomatic implants.

Effect of preoperative low-normal cervical length on perinatal outcome after laparotomy-assisted fetoscopic spina bifida repair.

To determine if preoperative cervical length in the low-normal range increases the risk of adverse perinatal outcome in patients undergoing fetoscopic spina bifida repair. This was a retrospective cohort study of patients who underwent fetal spina bifida repair between September 2014 and May 2022 at a single center. Cervical length was measured on transvaginal ultrasound during the week before surgery. Eligibility for laparotomy-assisted fetoscopic spina bifida repair was as per the criteria of the Management of Myelomeningocele Study, although maternal body mass index (BMI) up to 40 kg/m2 was allowed. Laparotomy-assisted fetoscopic spina bifida repair was performed, with carbon dioxide insufflation via two 12-French ports in the exteriorized uterus. All patients received the same peri- and postoperative tocolysis regimen, including magnesium sulfate, nifedipine and indomethacin. Postoperative follow-up ultrasound scans were performed either weekly (< 32 weeks' gestation) or twice a week (≥ 32 weeks). Perinatal outcome was compared between patients with a preoperative cervical length of 25-30 mm vs those with a cervical length > 30 mm. Logistic regression analyses and generalized linear mixed regression analyses were used to predict delivery at less than 30, 34 and 37 weeks' gestation. The study included 99 patients with a preoperative cervical length > 30 mm and 12 patients with a cervix 25-30 mm in length. One further case which underwent spina bifida repair was excluded because cervical length was measured > 1 week before surgery. No differences in maternal demographics, gestational age (GA) at surgery, duration of surgery or duration of carbon dioxide uterine insufflation were observed between groups. Cases with low-normal cervical length had an earlier GA at delivery (median (range), 35.2 (25.1-39.7) weeks vs 38.2 (26.0-40.9) weeks; P = 0.01), higher rates of delivery at < 34 weeks (41.7% vs 10.2%; P = 0.01) and < 30 weeks (25.0% vs 1.0%; P < 0.01) and a higher rate of preterm prelabor rupture of membranes (PPROM) (58.3% vs 26.3%; P = 0.04) at an earlier GA (mean ± SD, 29.3 ± 4.0 weeks vs 33.0 ± 2.4 weeks; P = 0.05) compared to those with a normal cervical length. Neonates of cases with low-normal cervical length had a longer stay in the neonatal intensive care unit (20 (7-162) days vs 9 (3-253) days; P = 0.02) and higher rates of respiratory distress syndrome (50.0% vs 14.4%; P < 0.01), sepsis (16.7% vs 1.0%; P = 0.03), necrotizing enterocolitis (16.7% vs 0%; P = 0.01) and retinopathy (33.3% vs 1.0%; P < 0.01). There was an association between preoperative cervical length and risk of delivery at < 30 weeks which was significant only for patients with a maternal BMI < 25 kg/m2 (odds ratio, 0.37 (95% CI, 0.07-0.81); P = 0.02). Low-normal cervical length (25-30 mm) as measured before in-utero laparotomy-assisted fetoscopic spina bifida repair may increase the risk of adverse perinatal outcomes, including PPROM and preterm birth, leading to higher rates of neonatal complications. These data warrant further research and are of critical relevance for clinical teams considering the eligibility of patients for in-utero spina bifida repair. Based on this evidence, patients with a low-normal cervical length should be aware of their increased risk for adverse perinatal outcome. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

A digital workflow to predict facial aesthetics in patients with maxillofacial trauma with implant retained prostheses.

Purpose To introduce a digital workflow for the prediction of facial aesthetics, especially in patients with dentation deformity caused by maxillofacial trauma.Methods Cone-beam computed tomography (CBCT) and three-dimensional facial scans of patients with radiographic prostheses were collected. The aforementioned data were uploaded to ProPlan CMF software and merged to generate a virtual patient with craniofacial hard tissue, realistic facial soft tissue, and remaining dentition. The radiographic prostheses were scanned to form a digital cast, which was fitted with its CBCT image to create the virtual prostheses. Postoperative facial soft tissue was simulated according to the movement of the virtual prostheses. An appropriate virtual diagnostic prosthesis plan was selected by the patient and dentist. Subsequently, prosthetically driven implant guide and restoration were designed and fabricated.Conclusions A virtual patient was successfully constructed. A 4-mm protrusion of the virtual prosthesis was chosen. Subsequently, implant surgery was performed, and dental prostheses were fabricated based on this location. The fusion of the postoperative facial scan and preoperative facial prediction was found to be coincident. This technique can effectively predict facial aesthetic features of patients with maxillofacial trauma, facilitate communication with patients, reduce chairside time, and guide the multidisciplinary design of implant placement and restoration fabrication.

Metastaze timoma u jetri - prikaz slučaja brzorastuće abdominalne mase kod trudnice

Introduction: Thymomas are the most common primary mediastinal tumors originating from epithelial cells of the thymus, demonstrating epithelial differentiation. Pathologically, thymomas exhibit relatively slow growth and typically spread directly, with extremely rare occurrences of distant dissemination to extrathoracic organs. The precise incidence of such dissemination remains unknown. Distant metastases, particularly to the liver, are exceptionally rare, with only a few cases documented in the literature. Case Report: A 39-year-old woman, in her 31st week of gestation, presented with abdominal pain and discomfort. She underwent ultrasonography, followed by an urgent MRI of the abdomen due to a protruding tumor mass in the liver. Shortly after delivering a healthy baby via cesarean section, she was admitted to the hospital for a CT scan of the abdomen. The imaging revealed multiple focal changes in the liver parenchyma, exhibiting radiological characteristics consistent with focal nodular hyperplasia. Less likely differential diagnoses included adenomas or hemangiomas. Subsequently, she underwent staged hepatectomy, and the results of the pathological analysis confirmed the presence of type B thymoma metastases in the liver. Conclusion: According to the available data in the literature, metastatic thymomas are often identified in patients who have previously undergone treatment for the primary disease. Our patient did not have a history of thymectomy, as confirmed by postoperative chest scans. Onset of symptoms during late pregnancy guided our diagnosis, relying on overall clinical and radiological findings of the detected tumor. Our treatment involved staged hepatectomy post-childbirth, followed by adjuvant chemotherapy. Further comprehensive studies are essential to precisely understand neoplasm behaviors like thymoma for timely detection and effective treatment.

Root Dilaceration: A Case Report and Literature Review

Abstract The clinical management of impacted incisors affected by root dilaceration is challenging. This case report presents the treatment of an adolescent female patient who presented with a deeply impacted, rotated and dilacerated maxillary central incisor and also reviews the current literature on the definition, prevalence, aetiology, diagnosis, and treatment of the anomaly. The impacted and dilacerated incisor was successfully orthodontically treated following a two-stage surgical exposure and after being rotated 100 degrees in the sagittal plane (due to the deep impaction and severe displacement). A Ballista spring and piggyback appliance technique were used to elevate the tooth. The dilacerated incisor was successfully preserved and relocated in the dental arch. The pre-operative and post-operative CBCT scans showed no significant root resorption of the repositioned tooth.

Biomechanics and early sac regression after endovascular aneurysm repair of abdominal aortic aneurysm

BackgroundSac regression after endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms (AAA) is regarded as a marker of successful response to treatment. Several factors influence sac behavior after EVAR, yet little is known about the value of preoperative biomechanics. The aim of this study was to investigate the difference in aortic biomechanics between patients with and without sac regression. MethodsPatients treated with standard EVAR for infrarenal AAA at the Karolinska University Hospital between 2009 and 2012 with one preoperative and a minimum of two postoperative computed tomography angiography (CTA) scans were considered for inclusion in this single-center retrospective cohort study. Biomechanical indices such as AAA wall stress and wall stress-strength ratio as well as intraluminal thrombus (ILT) thickness and stress were measured preoperatively in A4ClinicRE (VASCOPS GmbH). AAA diameter and volume were analyzed on preoperative, 30-day, and 1-year CTAs. Patients were dichotomized based on sac regression, defined as a ≥5 mm decrease in maximal AAA diameter between the first two postoperative CTA scans. Multivariable logistic regression was used for analysis of factors associated with early sac regression. ResultsOf the 101 patients treated during the inclusion period, 64 were included. Thirty-nine (61%) demonstrated sac regression and 25 (39%) had a stable sac or sac increase. The mean patients age (73 years vs 76 years), male sex (85% vs 96%), and median AAA diameter (58 mm vs 58.5 mm) did not differ between patients with and without sac regression. Although no difference in preoperative biomechanics was seen between the groups, multivariable logistic regression revealed that a larger AAA diameter (odds ratio [OR], 1.27; 95% confidence interval [CI], 1.06-1.51; P = .009) and smoking (OR, 22.1; 95% CI, 2.78-174; P = .003) were positively associated with sac regression. In contrast, the lumen diameter (OR, 0.87; 95% CI, 0.77-0.98; P = .023), ILT thickness (OR, 0.85; 95% CI, 0.75-0.97; P = .013), aspirin or direct-acting oral anticoagulant use (OR, 0.11; 95% CI, 0.02-0.61; P = .012), and mean ILT stress (OR, 0.35; 95% CI, 0.14-0.87; P = .024) showed a negative association. Patients with sac regression had fewer reinterventions (log-rank P = .010) and lower mortality (log-rank P = .012) at the 5-year follow-up. ConclusionsThis study, characterizing preoperative biomechanics in patients with and without sac regression, demonstrated a negative association between mean ILT stress and ILT thickness with a change in sac diameter after EVAR. Given that the ILT is a highly dynamic entity, further studies focusing on the role of the thrombus are needed. Furthermore, patients presenting with early sac regression had improved outcomes after EVAR.

Dosimetric feasibility of direct post-operative MR-Linac-based stereotactic radiosurgery for resection cavities of brain metastases

BackgroundPost-operative radiosurgery (SRS) of brain metastases patients is typically planned on a post-recovery MRI, 2–4 weeks after resection. However, the intracranial metastasis may (re-)grow in this period. Planning SRS directly on the post-operative MRI enables shortening this time interval, anticipating the start of adjuvant systemic therapy, and so decreasing the chance of extracranial progression. The MRI-Linac (MRL) allows the simultaneous execution of the post-operative MRI and SRS treatment. The aim of this work was investigating the dosimetric feasibility of MRL-based post-operative SRS. MethodsMRL treatments based on the direct post-operative MRI were simulated, including thirteen patients with resectable single brain metastases. The gross tumor volume (GTV) was contoured on the direct post-operative scans and compared to the post-recovery MRI GTV.Three plans for each patient were created: a non-coplanar VMAT CT-Linac plan (ncVMAT) and a coplanar IMRT MRL plan (cIMRT) on the direct post-operative MRI, and a ncVMAT plan on the post-recovery MRI as the current clinical standard. ResultsBetween the direct post-operative and post-recovery MRI, 15.5 % of the cavities shrunk by > 2 cc, and 46 % expanded by ≥ 2 cc. Although the direct post-operative cIMRT plans had a higher median gradient index (3.6 vs 2.7) and median V3Gy of the skin (18.4 vs 1.1 cc) compared to ncVMAT plans, they were clinically acceptable. ConclusionDirect post-operative MRL-based SRS for resection cavities of brain metastases is dosimetrically acceptable, with the advantages of increased patient comfort and logistics.Clinical benefit of this workflow should be investigated given the dosimetric plausibility.

DeepEOR: automated perioperative volumetric assessment of variable grade gliomas using deep learning

PurposeVolumetric assessments, such as extent of resection (EOR) or residual tumor volume, are essential criterions in glioma resection surgery. Our goal is to develop and validate segmentation machine learning models for pre- and postoperative magnetic resonance imaging scans, allowing us to assess the percentagewise tumor reduction after intracranial surgery for gliomas.MethodsFor the development of the preoperative segmentation model (U-Net), MRI scans of 1053 patients from the Multimodal Brain Tumor Segmentation Challenge (BraTS) 2021 as well as from patients who underwent surgery at the University Hospital in Zurich were used. Subsequently, the model was evaluated on a holdout set containing 285 images from the same sources. The postoperative model was developed using 72 scans and validated on 45 scans obtained from the BraTS 2015 and Zurich dataset. Performance is evaluated using Dice Similarity score, Jaccard coefficient and Hausdorff 95%.ResultsWe were able to achieve an overall mean Dice Similarity Score of 0.59 and 0.29 on the pre- and postoperative holdout sets, respectively. Our algorithm managed to determine correct EOR in 44.1%.ConclusionAlthough our models are not suitable for clinical use at this point, the possible applications are vast, going from automated lesion detection to disease progression evaluation. Precise determination of EOR is a challenging task, but we managed to show that deep learning can provide fast and objective estimates.