Endovascular Cerebral Venous Sinus Imaging with Optical Coherence Tomography.

BACKGROUND AND PURPOSE: Imaging of the cerebral venous sinuses has evolved Substantially during the past 2 decades, and most recently intravascular sinus imaging with sonography has shed light on the pathophysiology of sinus thrombosis and intracranial hypertension. Optical coherence tomography is the highest resolution intravascular imaging technique available but has not been previously used in cerebral sinus imaging. The purpose of this study was to develop a preclinical animal model of endovascular optical coherence tomography cerebral venous sinus imaging and compare optical coherence tomography findings with histology. MATERIALS AND METHODS: Four consecutive Yorkshire swine were selected. The superior sagittal sinus was first catheterized with a microwire, and the optical coherence tomography catheter was delivered via a monorail technique into the sinus. Luminal blood was cleared with a single arterial injection. After structural and Doppler optical coherence tomography imaging, a craniotomy was performed and the sinus and adjacent dura/veins were resected. Bland-Altman analysis was performed to compare optical coherence tomography and histology. RESULTS: Technically successful optical coherence tomography images were obtained in 3 of 4 swine. The luminal environment and visualization of dural arteries and draining cortical veins were characterized. The average maximum diameters of the sinus, dural arteries, and cortical veins were 3.14 mm, 135 µm, and 260 µm, respectively. Bland-Altman analysis demonstrated good agreement between histology and optical coherence tomography images. CONCLUSIONS: Endovascular optical coherence tomography imaging was feasible in this preclinical animal study. Adoption of this imaging technique in the human cerebral venous sinus could aid in the diagnosis, treatment, and understanding of the pathophysiology of various diseases of the sinus. Human safety and feasibility studies are needed.

Reoperation for inguinal hernia recurrence in Ontario: a population-based study.

PURPOSE: Despite the frequency with which inguinal hernia repairs (IHR) are performed, the real-world comparative effectiveness of laparoscopic versus open repairs is not well established. We compared the rate of recurrent inguinal hernia after laparoscopic and open mesh procedures. METHODS: We designed a population-based retrospective cohort study using linked administrative databases including adult patients in Ontario, Canada, who underwent primary IHR from April 1, 2003 to December 31, 2012. Patients were followed to August 31, 2014. Our primary outcome was reoperation for recurrent IHR, with covariate adjustment using Cox proportional hazards modeling. We constructed separate models to evaluate the effect of surgeon caseload on recurrence rates. RESULTS: We identified 93,501 adults undergoing primary IHR (85.4% open with mesh and 14.6% laparoscopic) with a median follow-up of 5.5 years. The 5-year cumulative risk of recurrent IHR was 2.0% in the open group and 3.4% in the laparoscopic group. After adjusting for patient and surgeon factors, we found that patients who underwent laparoscopic repair had a higher risk of recurrent IHR than those who underwent open repair when annual surgeon volume in the preceding year was ≤25 technique-specific cases (HR 1.76; 95% CI 1.45-2.13) or 26-50 technique-specific cases (HR 1.78; 95% CI 1.08-2.93). Few high-volume laparoscopic surgeons (> 50 cases/year) could be identified. Laparoscopic IHR did not carry a higher risk of recurrence for patients whose surgeons had performed > 50 technique-specific cases in the preceding year (HR 1.21; 95% CI 0.45-3.26). CONCLUSION: Laparoscopic IHR is generally associated with a higher risk of recurrence than open IHR. Though high-volume surgeons may be able to achieve equivalent results with laparoscopic and open techniques, few surgeons in our study population met this volume criterion for laparoscopic repairs.