Registration of preoperative temporal bone CT-scan to otoendoscopic video for augmented-reality based on convolutional neural networks.

PURPOSE: Patient-to-image registration is a preliminary step required in surgical navigation based on preoperative images. Human intervention and fiducial markers hamper this task as they are time-consuming and introduce potential errors. We aimed to develop a fully automatic 2D registration system for augmented reality in ear surgery. METHODS: CT-scans and corresponding oto-endoscopic videos were collected from 41 patients (58 ears) undergoing ear examination (vestibular schwannoma before surgery, profound hearing loss requiring cochlear implant, suspicion of perilymphatic fistula, contralateral ears in cases of unilateral chronic otitis media). Two to four images were selected from each case. For the training phase, data from patients (75% of the dataset) and 11 cadaveric specimens were used. Tympanic membranes and malleus handles were contoured on both video images and CT-scans by expert surgeons. The algorithm used a U-Net network for detecting the contours of the tympanic membrane and the malleus on both preoperative CT-scans and endoscopic video frames. Then, contours were processed and registered through an iterative closest point algorithm. Validation was performed on 4 cases and testing on 6 cases. Registration error was measured by overlaying both images and measuring the average and Hausdorff distances. RESULTS: The proposed registration method yielded a precision compatible with ear surgery with a 2D mean overlay error of 0.65 ± 0.60 mm for the incus and 0.48 ± 0.32 mm for the round window. The average Hausdorff distance for these 2 targets was 0.98 ± 0.60 mm and 0.78 ± 0.34 mm respectively. An outlier case with higher errors (2.3 mm and 1.5 mm average Hausdorff distance for incus and round window respectively) was observed in relation to a high discrepancy between the projection angle of the reconstructed CT-scan and the video image. The maximum duration for the overall process was 18 s. CONCLUSIONS: A fully automatic 2D registration method based on a convolutional neural network and applied to ear surgery was developed. The method did not rely on any external fiducial markers nor human intervention for landmark recognition. The method was fast and its precision was compatible with ear surgery.

Image-to-Patient Registration in Computer-Assisted Surgery of Head and Neck: State-of-the-Art, Perspectives, and Challenges.

Today, image-guided systems play a significant role in improving the outcome of diagnostic and therapeutic interventions. They provide crucial anatomical information during the procedure to decrease the size and the extent of the approach, to reduce intraoperative complications, and to increase accuracy, repeatability, and safety. Image-to-patient registration is the first step in image-guided procedures. It establishes a correspondence between the patient's preoperative imaging and the intraoperative data. When it comes to the head-and-neck region, the presence of many sensitive structures such as the central nervous system or the neurosensory organs requires a millimetric precision. This review allows evaluating the characteristics and the performances of different registration methods in the head-and-neck region used in the operation room from the perspectives of accuracy, invasiveness, and processing times. Our work led to the conclusion that invasive marker-based methods are still considered as the gold standard of image-to-patient registration. The surface-based methods are recommended for faster procedures and applied on the surface tissues especially around the eyes. In the near future, computer vision technology is expected to enhance these systems by reducing human errors and cognitive load in the operating room.

Frequency and visual outcomes of herpes simplex keratitis in a Kuwaiti tertiary referral center.

Background: Herpes simplex virus (HSV), a cause of many ocular pathologies, may affect the corneal epithelium, stroma, or endothelium, with the epithelium as the most frequently affected location. We aimed to determine the frequency and visual outcomes of HSV keratitis over a 1-year period at Farwaniya Hospital, Kuwait. Methods: This prospective observational case series included patients diagnosed with HSV keratitis who presented to the outpatient or eye casualty department between September 2022 and September 2023. Full history, demographic profile, detailed ocular and slit-lamp examinations, and visual acuity assessments were recorded prior to and after treatment. Baseline corneal sensation was assessed in the four corneal quadrants using the cotton wisp test. Results: Of the 227 patients who presented with infectious keratitis, 72 (31.7%) were diagnosed with HSV keratitis. The mean (SD) age was 45.86 (16.06) years, and 48 (66.7%) patients were male. The subtypes of HSV keratitis were endotheliitis in 27 (37.5%) patients, dendritic ulcer in 22 (30.6%), stromal keratitis with ulceration in 9 (12.5%) and without ulceration in 8 (11.1%), and geographic ulcer in 6 (8.3%). The mean baseline best-corrected distance visual acuity (BCDVA) differed significantly between the HSV keratitis subtypes (P < 0.001). Most patients (n = 70, 97.2%) had unilateral eye involvement, were treated within 1 - 2 weeks, and demonstrated improved BCDVA. Despite the improvement in BCDVA in all HSV keratitis subtypes, a significant difference in the median BCDVA remained after treatment (P < 0.001). Pairwise comparisons revealed a significantly better BCDVA after treatment in eyes with dendritic epithelial ulcers than in eyes with HSV stromal keratitis with ulceration (P = 0.003) or geographic epithelial ulcers (P = 0.005). After treatment, corneal haze and neovascularization were detected in 54 (75.0%) and 24 (33.3%) patients, respectively. Conclusions: We detected a substantial frequency of HSV keratitis in one of the governorates of Kuwait, with endotheliitis as the most common manifestation. Timely standard treatment interventions based on valid guidelines resulted in BCDVA improvement in all subtypes of HSV keratitis in our series, indicating the importance of early treatment. However, the BCDVA in eyes with dendritic epithelial ulcers remained substantially better than that in eyes with geographic epithelial ulcers or HSV stromal keratitis with ulceration, signifying the effect of the initial HSV keratitis subtype on visual outcomes. To our knowledge, this is the first study to highlight the frequency of HSV keratitis in a Kuwaiti hospital, and larger-scale research in this region is needed to further understand and manage the condition.

The Effect of Fluid Initiation Timing on Sepsis Mortality: A Meta-Analysis.

OBJECTIVE: Current guidelines suggest the immediate initiation of crystalloid for sepsis-induced hypoperfusion but note that supporting evidence is low quality. The aim of this study is to examine the effect of timing of fluid initiation on mortality for adults with sepsis. DATA SOURCES: Two authors independently reviewed relevant articles and extracted study details from PubMed, Scopus, Cochrane, Google Scholar, and previous relevant systematic reviews from 1-1-2000 to 1-6-2022. Registered with PROSPERO (CRD42021245431) and bias assessed using CLARITY. STUDY SELECTION: A minimum of severe sepsis (Sepsis-2) or sepsis (Sepsis-3) for patients ≥18 years old. Fluid initiation timing ranging from prehospital to 120 min within sepsis onset defined as "early" initiation. DATA EXTRACTION: Included studies providing mortality-based odds ratios (or comparable) adjusting for confounders or prospective trials. DATA SYNTHESIS: From 1643 citations, five retrospective cohort studies were included (n = 20,209) with in-hospital mortality of 21.8%. A pooled analysis (odds ratio = OR [95% CI]) did not observe an impact on mortality for the early initiation of fluids among all patients, OR = 0.79 [0.62-1.02]; heterogeneity: I2 = 86% [70-94%], but when studies analyzed cases of hypotension where available, a survival benefit was observed, OR = 0.74 [0.61-0.90]. Initiation of fluids in two prehospital studies did not impact mortality, OR = 0.82 [0.27-2.43]. However, both prehospital cohorts observed benefit among hypotensive patients individually, although heterogenous results precluded significance when pooled, OR = 0.50 [0.21-1.18]. Three hospital-based studies with initiation stratified at 30, 100, and 120 min, observed survival benefit both individually and when pooled, OR = 0.78 [0.63-0.97]. No differences were observed between prehospital versus hospital subgroups. CONCLUSION: This meta-analysis supports the guideline recommendations for early fluid initiation once sepsis is recognized, especially in cases of hypotension. Findings are limited by the small number, heterogeneity, and retrospective nature of available studies. Further retrospective investigations may be worthwhile as randomized studies on fluid initiation are unlikely.

In severe, uncontrolled asthma, tezepelumab reduced exacerbations and improved asthma control at 1 y.

SOURCE CITATION: Menzies-Gow A, Corren J, Bourdin A, et al. Tezepelumab in adults and adolescents with severe, uncontrolled asthma. N Engl J Med. 2021;384:1800-9. 33979488.

An Unusual Case of Urothelial Cell Carcinoma With Metastasis to the Pancreas.

Metastasis to the pancreas is far less common than primary pancreatic tumors. Bladder cancer metastasis involving the pancreas is rarely reported. Here, we report a case of metastasis to the pancreas of urothelial cell origin, diagnosed via upper endoscopic ultrasound-guided fine-needle aspiration and biopsy, and coupled with immunostaining. A high index of suspicion must be maintained for atypical metastatic locations of urothelial cell carcinoma, especially to the pancreas.

Spontaneous Bacterial Peritonitis Secondary to Salmonella spp. in a Patient With Decompensated Liver Cirrhosis.

Spontaneous bacterial peritonitis (SBP) is a common and serious complication of cirrhosis, with gram-negative bacteria being the culprit in most cases. SBP secondary to Salmonella spp. is rare. Here, we report a case of Salmonella enterica SBP in a patient with decompensated cirrhosis, diagnosed via paracentesis coupled with ascitic fluid analysis and culture. A high index of suspicion must be maintained for atypical causes of SBP, with prompt initiation of treatment.

WATS3D versus forceps biopsy in screening for Barrett's esophagus: experience in community endoscopy centers.

BACKGROUND: Barrett's esophagus (BE) is a premalignant condition diagnosed using systematic 4-quadrant forceps biopsies (FB) during endoscopy. This method is fraught with errors due to the randomness of sampling and variability among operators. Wide-area transepithelial sampling with 3-dimensional computer-assisted analysis (WATS3D) is an emerging technique used to collect esophageal samples. The aim of this study was to evaluate WATS3D as a diagnostic tool for detecting BE in addition to FB, compared to FB alone. METHODS: A retrospective observational cohort study was conducted and included patients who underwent screening for BE with WATS3D and FB between January 2015 and January 2019 across 3 endoscopy centers in Wichita, Kansas. The FB specimens were reviewed by community pathologists, while the WATS3D samples were sent to CDX technology labs, NY. RESULTS: A total of 108 patients were screened for BE using both modalities concurrently. FB and WATS3D detected 62 (57.4%) and 83 (76%) cases of BE, respectively. The absolute difference of 21 cases (18.6%) of BE was attributed to the addition of WATS3D. The number needed to test with WATS3D was 5. We divided the sample into 4 groups to compare the agreement across all groups: (FB-; WATS3D+), (FB-; WATS3D-), (FB+; WATS3D+), and (FB+ and WATS3D-). Overall agreement by kappa statistic was 0.74. CONCLUSION: WATS3D identified 21 cases of BE missed by FB. Using WATS3D in addition to FB increased the yield of BE during surveillance endoscopy, with no increase in complications.

Antitumor Efficacy of Ceranib-2 with Nano-Formulation of PEG and Rosin Esters.

Ceranib-2 is a recently discovered, poorly water-soluble potent ceramidase inhibitor, with the ability to suppress cancer cell proliferation and delay tumor growth. However, its poor water solubility and weak cellular bioavailability hinder its use as a therapeutic agent for cancer. PEGylated rosin esters are an excellent platform as a natural polymer for drug delivery applications, especially for controlling drug release due to their degradability, biocompatibility, capability to improve solubility, and pharmacokinetics of potent drugs. In this study, stable aqueous amphiphilic submicron-sized PEG400-rosin ester-ceranib-2 (PREC-2) particles, ranging between 100 and 350 nm in a 1:1 mixture, were successfully synthesized by solvent evaporation mediated by sonication.Conclusion: Stable aqueous PEGylated rosin ester nanocarriers might present a significant solution to improve solubility, pharmacokinetic, and bioavailability of ceranib-2, and hold promises for use as an anticancer adjacent drug after further investigations.

Sulfonylurea-Induced Hypoglycemia in a Patient With Cirrhosis.

Type 2 diabetes mellitus is highly prevalent among patients with cirrhosis. The pharmacological management of this disease in patients with chronic liver disease remains controversial, however. Insulin secretagogues such as sulfonylureas are associated with a high risk of hypoglycemia among diabetics. In patients with cirrhosis, this risk is more pronounced due to decreased hepatic clearance, concurrent alcoholism, hypoalbuminemia, and acute liver decompensation. In this case report, we present a case of severe refractory hypoglycemia secondary to glipizide in a patient with alcoholic cirrhosis. We believe that the use of sulfonylureas in this patient population should be contraindicated to avoid debilitating neurologic damage and death following hypoglycemia.

Lack of adenylate cyclase 1 (AC1): consequences on corticospinal tract development and on locomotor recovery after spinal cord injury.

Cyclic AMP (cAMP) signalling pathways are involved in axonal growth and regeneration. The calcium-calmodulin- stimulated adenylate cyclase 1 (AC1), a regulator of cAMP levels, is strongly expressed in the corticospinal motor neurons (CSMN) in cerebral cortex layer V during development, but its role in the development of the corticospinal tract (CST) is unknown. Here, we analyse the organization of the CST pathway using anterograde and retrograde tracers in the barrelless (brl) mouse that carries an inactivating mutation of the AC1 gene. We show that in brl mice the general organization of the CST is normal but there is an increase in the number of axons in the ipsilateral contingent in the dorsal and ventral medial funiculi of the cervical spinal cord. The density of CSMN in layer V of the motor cortex is increased in brl compared to wild-type mice. Thus, lack of AC1 likely perturbs late phases of CSMN and CST development. Next, we examine the motor recovery after a spinal cord injury (SCI). We find that brl mice show enhanced locomotor functions as assessed by the BMS (Basso mouse scale) as early as 6h and up to 6 weeks after SCI, indicating a smaller responsiveness of brl mice to SCI. It is therefore possible that developmental effects on motor systems might decrease the locomotor effects consecutive to a SCI. This point is particularly important with regards to the use of transgenic animals for testing SCI recovery.

Management of perforated peptic ulcer in patients at a teaching hospital.

OBJECTIVE: To explore and analyze the current status in management of patients with perforated peptic ulcers (PPU). METHODS: A retrospective study carried out at the Surgical Department, Al-Gamhouria Teaching Hospital, Aden, Yemen. Patients admitted with perforated benign peptic ulcers from January 1997 to December 2006 were included in the study. RESULTS: A total of 156 patients, 138 (88.5%) male and 18 (11.5%) female, with an overall mean age of 39.08 years (range 14-75 years) and a higher frequency of PPU was noted in patients 21-40 years (58.3%). The perforated duodenal ulcer and perforated gastric ulcer ratio was 4.38:1. The mean time of presentation was 16.5 hours, and operative intervention after admission was 5.25 hours. Simple perforation closure was used in 91.7% of the patients. Postoperative complication rate was 41% (statistically significant in cases admitted later than 12 hours), wound sepsis making the majority at 55.2%, 6 deaths (3.9%), the correlation with presentation time was not significant. The overall mean post-operative hospitalization period was 12.76 days; 14.7% of the patients stayed more than 3 weeks. CONCLUSION: Younger patients (21-40 years) were frequently affected. Emphasis should be placed on shortening the time to surgery. Simple closure remains the selected treatment in the majority of patients. Overall post-operative mortality was low (3.9%). Improving the surgical skills, wound care, administrative regulations, hospital environment, and equipment are needed to reduce the high rate of complications.