Radiation exposure during direct versus indirect image acquisition during fluoroscopy-controlled internal fixation of a hip fracture: Results of a randomized controlled trial.

BACKGROUND: Intra-operative image acquisition can be obtained indirectly (via verbal request to a technician) or directly (executed at the tableside, by a surgeon stepping on a foot pedal). Direct image acquisition could reduce the exposure time and thus the risk of radiation damage. The aim of this randomized controlled trial was to compare direct surgeon-controlled fluoroscopy with indirect technician-operated fluoroscopy during internal fixation of a hip fracture. METHODS: From March 5, 2014 to August 19, 2015, 100 patients who had sustained a hip fracture that required internal fixation were enrolled. Patients were randomized between direct surgeon-controlled image acquisition using a foot pedal (n = 52) and indirect image acquisition by a radiology technician (n = 48). The primary outcome measure was the radiation exposure time; secondary outcome measures were the associated effective radiation dose and the dose area product. (DAP) RESULTS: A total of 96 patients (with a median age of 84 years) were enrolled in this study. Eighty-nine (93%) patients had a pertrochanteric fracture. No statistically significant differences between direct image acquisition and indirect image acquisition were found for overall radiation time, total radiation dose or DAP for the total population. When adjusted for potential confounders, a difference in overall radiation time of 18.50 s (95% CI 2.19; 34.81, p = 0.027) was found in favour of indirect image acquisition. CONCLUSION: This study showed statistically significantly lower radiation duration using indirect fluoroscopy for the total population and the pertrochanteric fracture subgroup when adjusted for several confounders. No significant effect on radiation dose and DAP was found.

Atherosclerotic plaque in the left carotid artery is more vulnerable than in the right.

BACKGROUND AND PURPOSE: Ischemic stroke is more often diagnosed in the left hemisphere than in the right. It is unknown whether this asymmetrical prevalence relates to differences in carotid atherosclerosis. We compared atherosclerotic plaque prevalence, severity, and composition between left and right carotid arteries. METHODS: In a population-based cohort, carotid MRI scanning was performed in 1414 stroke-free participants (≥45 years). Using a multisequence MRI protocol, we assessed the prevalence, stenosis, and thickness of the plaque and its predominant component (ie, lipid core, intraplaque hemorrhage, calcification, or fibrous tissue in each carotid artery). Differences between left and right side were tested using paired t tests, McNemar test and Generalized Estimating Equation analyses. RESULTS: The majority (85%) of the participants had bilateral carotid plaques. Unilateral plaques were twice more prevalent on the left than on the right side (67% versus 33%; P<0.001). Plaque thickness was also greater on the left (3.1±1.2 versus 2.9±1.3 mm; P<0.001); degree of stenosis did not differ. Intraplaque hemorrhage and fibrous tissue were more prevalent on the left (9.1 versus 5.9%; P<0.001 and 45.0 versus 38.5%; P<0.001), whereas calcification occurred more often on the right (37.4 versus 31.6% at the left; P<0.001). Lipid was equally distributed. CONCLUSIONS: Carotid atherosclerotic plaque size and composition are not symmetrically distributed. Predominance of intraplaque hemorrhage in left-sided carotid plaques suggests a greater vulnerability as opposed to right-sided plaques, which are more calcified and therefore considered more stable.

Predictors of outcome after transanal advancement flap repair for high transsphincteric fistulas.

BACKGROUND: Transanal advancement flap repair fails in 1 of every 3 patients with a high transsphincteric fistula. It has been reported that smoking, obesity, and previous attempts at repair adversely affect the outcome of transanal advancement flap repair. Because these findings could not be confirmed by other studies, it is still unclear whether these and other factors have an impact on the outcome. OBJECTIVE: The aim of this study was to identify predictors of outcome in a large cohort of patients who underwent transanal advancement flap repair for a high transsphincteric fistula. DESIGN: This study was performed as a retrospective review. SETTINGS: The study was conducted at the Division of Colon and Rectal Surgery, Erasmus MC, between 2000 and 2012. PATIENTS: A consecutive series of 252 patients with a high transsphincteric fistula of cryptoglandular origin were included. Patients with a rectovaginal or Crohn fistula were excluded. INTERVENTIONS: All patients underwent transanal advancement flap repair. Preoperatively, patients underwent endoanal MRI. MAIN OUTCOME MEASURES: Healing was defined as complete wound healing with absence of symptoms. Patients were followed up to assess failure. Seventeen patient- and fistula-related variables were assessed. RESULTS: Median duration of follow-up was 21 months (range, 6-136 months). The failure rate at 3 years was 41% (95% CI, 34-48). None of the studied variables predicted the outcome of flap repair except horseshoe extension. In univariate and multivariate analyses, significantly less failures were observed in patients with a horseshoe extension (p < 0.05). LIMITATIONS: Retrospective design, a single surgeon series, and potential selection bias caused by the tertiary referral center status are the limitations of this study. CONCLUSIONS: Of all studied variables, horseshoe extension was found to be the only positive predictor of outcome after flap repair for high transsphincteric fistulas.

[Intersphincteric ligation of perianal fistula]. / Intersfincterische ligatie van perianale fistels.

Fistulotomy is inappropriate for patients with a high transsphincteric fistula, passing through the upper or middle third of the external anal sphincter, because this procedure requires division of a large part of the anal sphincter, with subsequent risk of fecal incontinence. Therefore, sphincter preserving procedures have been developed for the treatment of high transsphincteric fistulas, such as flap repair. In most hospitals, fistulotomy is still the treatment of choice for low transsphincteric fistula, passing through the lower third of the external anal sphincter. Although this procedure is considered simple and effective with a minimal risk of incontinence, data suggest that the risk of diminished fecal continence is not insignificant. Ligation of the intersphincteric fistula tract (LIFT) is a new sphincter preserving technique. This technique may be a sphincter preserving alternative for fistulotomy in low transsphincteric fistulas and for flap repair in high transsphincteric fistulas.

Treatment of anal fistulas with high intersphincteric extension.

BACKGROUND: Intersphincteric fistulas with a high upward extension, up to or above the level of the puborectal muscle, in the intersphincteric plane are rare. Most of these fistulas have no external opening and they are frequently associated with a high intersphincteric and/or supralevator abscess. Division of a large amount of internal anal sphincter by extended fistulotomy has a potential risk of diminished fecal continence. OBJECTIVE: The aim of this study was to evaluate flap repair combined with drainage of associated abscesses in high intersphincteric fistulas. DESIGN: This study was performed as a retrospective review. SETTINGS: The study was conducted at the Division of Colon and Rectal Surgery, Erasmus MC, between March 1995 and February 2011. PATIENTS: Fourteen patients with a cryptoglandular fistula with high intersphincteric extension were included. INTERVENTIONS: Transanal advancement flap repair combined with intersphincteric and/or extrasphincteric drainage of associated abscesses was performed. Preoperatively, patients underwent endoanal MRI. MAIN OUTCOME MEASURES: Healing was defined as complete wound healing with absence of symptoms. Patients were followed up to assess the recurrence rate and Rockwood fecal continence score. RESULTS: In 1 patient the fistula was not associated with an abscess. In 10 patients the fistula tract ended in a high intersphincteric abscess. Three patients presented with a high intersphincteric abscess and a supralevator abscess. Primary healing was observed in 79% of the patients. The 3 patients without primary healing had a supralevator abscess. In these patients, healing was obtained after a second, third, and fourth procedure. The overall healing rate was 100%. Median postoperative Rockwood score was 0 (range, 0-15). LIMITATIONS: Retrospective design and lack of baseline continence data were the limitations of this study. CONCLUSIONS: Since most high intersphincteric fistulas have no external opening and are frequently associated with abscesses, preoperative imaging is useful. Flap repair with adequate drainage of the abscesses is successful, except in fistulas with supralevator extension. However, healing may be achieved by additional procedures.

Semiautomatic carotid lumen segmentation for quantification of lumen geometry in multispectral MRI.

Quantitative information about the geometry of the carotid artery bifurcation is relevant for investigating the onset and progression of atherosclerotic disease. This paper proposes an automatic approach for quantifying the carotid bifurcation angle, carotid area ratio, carotid bulb size and the vessel tortuosity from multispectral MRI. First, the internal and external carotid centerlines are determined by finding a minimum cost path between user-defined seed points where the local costs are based on medialness and intensity. The minimum cost path algorithm is iteratively applied after curved multi-planar reformatting to refine the centerline. Second, the carotid lumen is segmented using a topology preserving geodesic active contour which is initialized by the extracted centerlines and steered by the MR intensities. Third, the bifurcation angle and vessel tortuosity are automatically extracted from the segmented lumen. The methods for centerline tracking and lumen segmentation are evaluated by comparing their accuracy to the inter- and intra-observer variability on 48 datasets (96 carotid arteries) acquired as part of a longitudinal population study. The evaluation reveals that 94 of 96 carotid arteries are segmented successfully. The distance between the tracked centerlines and the reference standard (0.33 mm) is similar to the inter-observer variation (0.32 mm). The lumen segmentation accuracy (average DSC=0.89, average mean absolute surface distance=0.31 mm) is close to the inter-observer variation (average dice=0.92, average mean surface distance=0.23 mm). The correlation coefficient of manually and automaticly derived bifurcation angle, carotid proximal area ratio, carotid proximal bulb size and vessel totuosity quantifications are close to the correlation of these measures between observers. This demonstrates that the automated method can be used for replacing manual centerline annotation and manual contour drawing for lumen segmentation in MRIs data prior to quantifying the carotid bifurcation geometry.

A semi-automatic method for segmentation of the carotid bifurcation and bifurcation angle quantification on black blood MRA.

Quantitative information about the geometry of the carotid artery bifurcation may help in predicting the development of atherosclerosis. A geodesic active contours based segmentation method combining both gradient and intensity information was developed for semi-automatic, accurate and robust quantification of the carotid bifurcation angle in Black Blood MRA data. The segmentation method was evaluated by comparing its accuracy to inter and intra observer variability on a large dataset that has been acquired as part of a longitudinal population study which investigates the natural progression of carotid atherosclerosis. Furthermore, the method is shown to be robust to initialization differences. The bifurcation angle obtained from the segmented lumen corresponds well with the angle derived from the manual lumen segmentation, which demonstrates that the method has large potential to replace manual segmentations for extracting the carotid bifurcation angle from Black Blood MRA data.