Unveiling the potential of strain elastography in perihilar cholangiocarcinoma biopsies.

PURPOSE: This study was conducted to investigate the effectiveness of strain elastography in guiding precise and sufficient tissue sampling for perihilar cholangiocarcinoma (CCA) biopsies. METHODS: Our retrospective analysis included 23 liver biopsies conducted between March 2019 and July 2022 for suspected perihilar CCA. An experienced radiologist performed the biopsies via an ultrasound machine with elastography configuration. Tissue stiffness color maps were used for guiding when the biopsies were performed. Strain index value calculations were made by radiologists on recorded images. RESULTS: Patient demographics revealed a mean age of 65.17 ± 9.25 years, with a gender distribution of six females and 17 males. Gray-scale examinations unveiled diverse echogenic characteristics in liver lesions. Elastography-guided biopsies demonstrated no need for repeats, while gray-scale biopsies necessitated re-biopsy in four patients, resulting in cholangiocarcinoma diagnosis (P = 0.037). Strain index values showcased strong inter- and intra-observer agreements (P < 0.001). Notably, no post-biopsy complications emerged in either study group. CONCLUSION: The diagnostic advantage of elastography, particularly in enhancing accuracy in challenging isoechoic lesions, was demonstrated, although the substantial overlap between strain index values of benign and malignant liver masses limits clinical usefulness of this technique.

Effect of sarcopenia on mortality in acute stroke patients receiving endovascular treatment.

BACKGROUND: To investigate the effect of sarcopenia on mortality in patients with acute ischemic stroke caused by anterior circulation large artery occlusion who underwent endovascular treatment. METHODS: Acute ischemic stroke patients (n = 194) treated with mechanical thrombectomy who underwent chest computed tomography between 2019 and 2022 (median age, 69 [interquartile range: 61-77], 95 females, 99 males) were evaluated retrospectively. The cross-sectional area and density of the pectoralis muscle [pectoralis muscle area (PMA) and pectoralis muscle density (PMD)] at the level of the aortic arch and the erector spinae muscle at the T12 level [erector spinae muscle area (ESMA) and erector spinae muscle density (ESMD)] were measured. The association between skeletal muscle parameters and mortality outcomes was investigated using the receiver operating characteristic (ROC) curve and multivariable logistic regression analyses. RESULTS: The 90-day mortality rate was 32% in the study population (n = 62). The ROC analysis revealed that ESMD [area under the curve (AUC): 0.765] and PMD (AUC: 0.759) performed best in the prediction of 90-day mortality. In the multivariable logistic regression analysis, PMD [odds ratio (OR): 0.896; 95% confidence interval (CI): 0.846-0.948; p < 0.001], ESMA (OR: 0.929; 95% CI: 0.878-0.983; p = 0.011), and ESMD (OR: 0.947; 95% CI: 0.913-0.983; p = 0.004), but not PMA, were independent risk factors for 90-day mortality. CONCLUSION: PMD, ESMA, and ESMD may be risk factors for 90-day mortality after mechanical thrombectomy for acute ischemic stroke.

Elevating healthcare through artificial intelligence: analyzing the abdominal emergencies data set (TR_ABDOMEN_RAD_EMERGENCY) at TEKNOFEST-2022.

OBJECTIVES: The artificial intelligence competition in healthcare at TEKNOFEST-2022 provided a platform to address the complex multi-class classification challenge of abdominal emergencies using computer vision techniques. This manuscript aimed to comprehensively present the methodologies for data preparation, annotation procedures, and rigorous evaluation metrics. Moreover, it was conducted to introduce a meticulously curated abdominal emergencies data set to the researchers. METHODS: The data set underwent a comprehensive central screening procedure employing diverse algorithms extracted from the e-Nabiz (Pulse) and National Teleradiology System of the Republic of Türkiye, Ministry of Health. Full anonymization of the data set was conducted. Subsequently, the data set was annotated by a group of ten experienced radiologists. The evaluation process was executed by calculating F1 scores, which were derived from the intersection over union values between the predicted bounding boxes and the corresponding ground truth (GT) bounding boxes. The establishment of baseline performance metrics involved computing the average of the highest five F1 scores. RESULTS: Observations indicated a progressive decline in F1 scores as the threshold value increased. Furthermore, it could be deduced that class 6 (abdominal aortic aneurysm/dissection) was relatively straightforward to detect compared to other classes, with class 5 (acute diverticulitis) presenting the most formidable challenge. It is noteworthy, however, that if all achieved outcomes for all classes were considered with a threshold of 0.5, the data set's complexity and associated challenges became pronounced. CONCLUSION: This data set's significance lies in its pioneering provision of labels and GT-boxes for six classes, fostering opportunities for researchers. CLINICAL RELEVANCE STATEMENT: The prompt identification and timely intervention in cases of emergent medical conditions hold paramount significance. The handling of patients' care can be augmented, while the potential for errors is minimized, particularly amidst high caseload scenarios, through the application of AI. KEY POINTS: • The data set used in artificial intelligence competition in healthcare (TEKNOFEST-2022) provides a 6-class data set of abdominal CT images consisting of a great variety of abdominal emergencies. • This data set is compiled from the National Teleradiology System data repository of emergency radiology departments of 459 hospitals. • Radiological data on abdominal emergencies is scarce in literature and this annotated competition data set can be a valuable resource for further studies and new AI models.

Ground level falls: computed tomography findings and clinical outcomes by age groups.

BACKGROUND: This study aimed to determine injury patterns in ground level falls (GLFs) and investigate the effect of age on the severity of injury. METHODS: We retrospectively identified 4,712 patients who presented to a Level 1 trauma center due to GLFs and analyzed the data of 1,214 patients who underwent computed tomography (CT). Demographics, torso examination findings, and injuries detected on CT were recorded. To investigate the effect of age on injury severity, the patients were grouped as those aged <65 and ≥65 years. RESULTS: The mean age was 57 years, and 55.20% of the patients were female. The mortality rate was 0.50%. Injury was detected in 489 (40.30%) patients on CT. Fractures were the most common injury type. Traumatic intracranial hemorrhage was detected in 32 (2.60%) patients. Only three (0.20%) of the 63 patients with rib fractures had concomitant lung injury. The negative predictive value of the physical examination (PE) was 95.80% for chest injury. Intra-abdominal injury was not detected in any of the 116 patients who underwent abdominal CT. Hospitalization was also higher in the ≥65-year group (p<0.001). All mortalities (n=6) were seen in patients aged ≥65 years. CONCLUSION: Our results indicate that GLFs cause more injuries in the elderly, resulting in more hospitalizations and mortality. Normal PE findings may reduce the need for whole-body CT in GLF patients who are conscious, cooperative, and oriented.

The effects of smoking cessation on the ratios of neutrophil/lymphocyte, platelet/lymphocyte, mean platelet volume/lymphocyte and monocyte/high-density lipoprotein cholesterol.

The amount of smoking, level of smoking addiction and smoking cessation have effects on blood cells, blood lipid levels, neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), mean platelet volume (MPV)/lymphocyte ratio (MPVLR) and monocyte/high- density lipoprotein (HDL) ratio (MHR). Methods In this self-controlled experimental study, we included individuals who applied to a smoking cessation clinic and quit smoking. Their sociodemographic and clinical characteristics, the amount of cigarettes consumed (pack/year), their Fagerstrom test for nicotine dependence (FTND) results, haemogram values before and 6 months after quitting smoking, NLR, PLR, MPVLR, MHR and blood lipid levels before and after the treatment were compared retrospectively. Results The mean (SD) age of the 239 individuals who participated in the study was 41.7 (10.9) years and 55.2% of them were women. Their mean FTND score was 7.06 (2.0), and most of them (47.7%) had a very high level of addiction. After the smoking cessation treatment, their neutrophil, platelet, MPV, red cell distribution width, platelet distribution width (PDW), cholesterol, triglyceride, low- density lipoprotein, NLR, PLR, MPVLR, MHR and HDL values increased (p<0.05). The amount of smoking and level of dependence were negatively correlated with HDL, and positively correlated with other parameters. Conclusion After smoking cessation, in addition to dyslipidaemia, the NLR, PLR, MPVLR and MHR values also decreased, and the difference was found to correlate with the level of addiction and the amount of smoking.

Artificial Intelligence in Healthcare Competition (TEKNOFEST-2021): Stroke Data Set.

OBJECTIVE: The artificial intelligence competition in healthcare was organized for the first time at the annual aviation, space, and technology festival (TEKNOFEST), Istanbul/Türkiye, in September 2021. In this article, the data set preparation and competition processes were explained in detail; the anonymized and annotated data set is also provided via official website for further research. MATERIALS AND METHODS: Data set recorded over the period covering 2019 and 2020 were centrally screened from the e-Pulse and Teleradiology System of the Republic of Türkiye, Ministry of Health using various codes and filtering criteria. The data set was anonymized. The data set was prepared, pooled, curated, and annotated by 7 radiologists. The training data set was shared with the teams via a dedicated file transfer protocol server, which could be accessed using private usernames and passwords given to the teams under a nondisclosure agreement signed by the representative of each team. RESULTS: The competition consisted of 2 stages. In the first stage, teams were given 192 digital imaging and communications in medicine images that belong to 1 of 3 possible categories namely, hemorrhage, ischemic, or non-stroke. Teams were asked to classify each image as either stroke present or absent. In the second stage of the competition, qualifying 36 teams were given 97 digital imaging and communications in medicine images that contained hemorrhage, ischemia, or both lesions. Among the employed methods, Unet and DeepLabv3 were the most frequently observed ones. CONCLUSION: Artificial intelligence competitions in healthcare offer good opportunities to collect data reflecting various cases and problems. Especially, annotated data set by domain experts is more valuable.

Association of diaphragm thickness and density measured on chest CT with disease severity in COVID-19 patients.

INTRODUCTION: A decrease in muscle mass of the diaphragm could be a significant risk factor for pneumonia. The aim of our study was to evaluate whether diaphragm thickness (DT) and density measured on chest computed tomography (CT) were associated with clinical course and mortality in adult patients with coronavirus disease 2019 (COVID-19) in emergency department admission. METHODS: We retrospectively analyzed 404 patients with a positive polymerase chain reaction test for COVID-19 and pneumonia findings on chest CT between September 1 and November 1, 2020. Bilateral DT measurements were performed at the level of the celiac artery origin, and the total mean diaphragm thickness (TMDT) was estimated. Hemidiaphragm density was measured at the level of the celiac artery origin. The relationship between demographic characteristics, comorbidities, TMDT, mean hemidiaphragm density (MHD) and clinical outcomes was investigated using the logistic regression analyses. The reliability of the measurement of the two observers was evaluated by intraclass correlation analyses. RESULTS: Intraclass correlation analyses demonstrated almost perfect inter-observer agreement for TMDT and substantial agreement for MHD. There was a statistically significant relationship between the presence of a thinner diaphragm and mortality (p < 0.001). Bilateral diaphragm densities were lower in the patients with severe disease and mortality (p < 0.001). The threshold values of TMDT were 3.67 mm and 3.47 mm for the prediction of ICU admission and mortality, respectively. TMDT (odds ratio [OR]: 0.634, 95% confidence interval [CI]: 0.447-0.901), age (OR: 1.053, 95% CI: 1.027-1.081) and MHD (OR: 0.920, 95% CI: 0.883-0.959) were found to be independent predictors for severe disease in the multivariable model. In addition, MHD (OR: 0.883, 95% CI: 0.827-0.942) and age (OR: 1.040, 95% CI: 1.003-1.078) were independent risk factors for mortality. CONCLUSION: Our study demonstrated that a low diaphragm thickness and density measured on chest CT were associated with severe disease in patients with COVID-19 and could be evaluated as poor prognostic markers.

Shear wave elastography for the evaluation of testicular salvage after testicular torsion.

The aim of this study was to assess the utility of shear wave elastography in the follow-up of testicular detorsion, evaluate long-term outcomes, and explore its relationship with parameters such as tissue stiffness values, pain duration, and torsion type. Elastography examinations were independently performed by two radiologists to evaluate patients who presented to our hospital for follow-up after being diagnosed with testicular torsion and age-matched controls. Inter-observer variability of the mean testicular tissue elasticity was excellent (Intraclass correlation coefficient: 0.939, p < 0.001). Median time between testicular detorsion and follow-up ultrasound examination was 18 months (range, 11-36 months). Torsion side, torsion degree, and pain duration were recorded, and testicular volumes were calculated. The study population comprised 24 patients (48 testes) with a mean age of 21.1 ± 7.8 years. The mean testicular volume was measured as 12.3 ± 5.4 ml for the testicular salvage group, 13.9 ± 3.8 ml for the contralateral testes, and 13.7 ± 2.7 ml for the control group (p = 0.553). The mean testicular speed mode values were higher in the testicular salvage group (1.34 ± 1.21 m/s) compared with the contralateral testes group (1.00 ± 0.08 m/s), and the control group (1.01 ± 0.06 m/s), however there was no statistically significant difference between the three groups (p = 0.861). While testicular atrophy was detected in three patients, an intraparenchymal wedge-shaped focal hypoechoic area developed after torsion in a further three patients. The elastography examination for focal hypoechoic areas revealed an increase or decrease in tissue stiffness compared to the normal parenchyma. The tissue stiffness values of the testicular salvage group were higher in complete torsion compared to incomplete torsion. The elastography method contributes to other imaging methods in distinguishing focal lesion areas that can be seen after testicular torsion from malignant conditions. Elastography presents as a feasible and practical complementary modality for the follow-up of testicular salvage after torsion.

The predictive value of epicardial fat volume for clinical severity of COVID-19.

Introduction: Epicardial adipose tissue serves as a source of inflammatory cytokines and mediators. Cytokine storm is an important cause of morbidity and mortality in coronavirus disease 2019 (COVID-19). Objectives: To investigate the association between epicardial fat volume (EFV), inflammatory biomarkers and clinical severity of COVID-19. Methods: This retrospective study included 101 patients who were infected with COVID-19. Serum inflammatory biomarkers including C-reactive protein (CRP), interleukin-6 (IL-6), procalcitonin (PCT) and ferritin levels were measured. Computed tomography images were analyzed and semi-automated measurements for EFV were obtained. The primary composite endpoint was admission to the intensive care unit (ICU) or death. Results: The primary composite endpoint occurred in 25.1% (n=26) of patients (mean age 64.8±14.8 years, 14 male). A total of 10 patients died. EFV, CRP, PCT, ferritin and IL-6 levels were significantly higher in ICU patients. Moreover, a positive correlation was determined between EFV and CRP (r: 0.494, p<0.001), PCT (r: 0.287, p=0.005), ferritin (r: 0.265, p=0.01) and IL-6 (r: 0.311, p=0.005). On receiver operating characteristic analysis, patients with EFV >102 cm3 were more likely to have severe complications. In multivariate logistic regression analysis, EFV independently predicted admission to the ICU at a significant level (OR: 1.02, 95% CI: 1.01-1.03, p=0.025). Conclusion: EFV and serum CRP, IL-6, PCT and ferritin levels can effectively assess disease severity and predict the outcome in patients with COVID-19. EFV is an independent predictor of admission to the ICU in hospitalized COVID-19 patients.

Introdução: O tecido adiposo epicárdico é fonte de citocinas inflamatórias e mediadores. A tempestade de citocinas é uma importante causa de morbilidade e mortalidade na doença coronavírus 2019 (COVID-19). Objetivos: Investigar a associação entre volume adiposo epicárdico (VAE), biomarcadores inflamatórios e gravidade clínica da COVID-19. Métodos: Este estudo retrospetivo incluiu 101 doentes infetados com COVID-19. Foram avaliados biomarcadores inflamatórios séricos, incluindo os níveis de proteína C-reativa (PCR), de interleucina-6 (IL-6), de procalcitonina (PCT) e de ferritina. Foram analisadas imagens de tomografia computorizada (TC) e foram obtidas medições semi-automáticas do VAE. O endpoint primário composto foi a admissão na unidade de cuidados intensivos (UCI) ou morte. Resultados: O endpoint primário ocorreu em 25,1% (n=26) dos doentes (idade média 64,8±14,8 anos, 14 homens). Um total de 10 doentes morreu. Os níveis de VAE, PCR, PCT, ferritina e IL-6 foram significativamente superiores nos doentes internados na UCI. Além disso, verificou-se uma correlação positiva entre o VAE e a PCR (r: 0,494, p<0,001), PCT (r: 0,287, p=0,005), ferritina (r: 0,265, p=0,01) e IL-6 (r: 0,311, p=0,005). Na análise de regressão logistica multivariada, os doentes com VAE>102 cm3 tinham maior probabilidade de ter complicações graves. Conclusão: O VAE e os níveis séricos de PCR, IL-6, PCT e ferritina podem avaliar a gravidade da doença e prever o resultado em doentes com COVID-19. O VAE constitui um fator preditivo na admissão dos doentes hospitalizados com COVID-19 numa UCI.

Sarcopenia and Its Prognostic Role on Hospitalization and In-Hospital Mortality in Coronavirus Disease 2019 Patients with At Least One Cardiovascular Risk Factor.

BACKGROUND: The coronavirus disease 2019 infection is a global pandemic that has affected the whole world population. We aimed to evaluate the prognostic role of cross-sectional area, muscle index, and muscle attenuation values in computed tomography-based skeletal groups [erector spinae muscle, pectoralis muscle, and total skeletal muscle] of patients hospitalized for coronavirus disease 2019 and with at least 1 cardiovascular risk factor. METHODS: A total of 232 patients with coronavirus disease 2019 and at least 1 cardiovascular risk factor were enrolled in the study, retrospectively. The cross-sectional area, muscle index, and attenuation of erector spine muscle, pectoralis muscle, and total skeletal muscle were automatically measured on computed tomography images. The study population was assigned into tertiles on the basis of the total SMcsa index. The relationship between the values obtained and the length of hospital stay, admission to intensive care unit, the need for invasive mechani cal ventilation, and mortality was investigated. RESULTS: Admission to intensive care unit, need for invasive mechanical ventilation, and mor tality were higher at tertile 3 groups than in the other groups (all P values <.001). Statistically, all muscle measurements were significantly lower in tertile 3 (P <.001). Diabetes mellitus, hypertension, and total SMcsa index were predictors of in-hospital mortality in patients with coronavirus disease 2019 on the basis of Cox regression analysis. In the Kaplan-Meier analysis for the proportion of survivors relative to the total SMcsa index, tertile 3 had the highest mortal ity (survival rates 57%, P < .001). CONCLUSIONS: Sarcopenia and attendant cardiovascular comorbidities can effectively assess dis ease severity and predict outcome in patients with coronavirus disease 2019.

Investigation of the relationship of the number, localization, and displacement of rib fractures with intrathoracic structures and abdominal solid organ complications using computed tomography.

PURPOSE: This study aimed at evaluating the fracture properties, intrathoracic structures, and abdominal solid organ complications in patients with traumatic rib fractures. METHODS: Chest CT images of 305 patients were retrospectively evaluated to determine the number and level of rib fractures and measure the magnitude of displacement. The relationship of rib fractures and displacement patterns with intrathoracic structures and abdominal solid organ complications was investigated. RESULTS: The fractures were most located in the fifth, sixth, and seventh ribs. The mean age of the patients with displaced fractures was statistically significantly higher than the non-displaced fracture group with pneumothorax, hemothorax or lung injury. RibScore was statistically significantly higher in patients with pneumothorax, hemothorax, and lung parenchyma injury, as well as those with liver, spleen, and kidney injury. Hepatic, splenic, and renal injuries were markedly higher in patients with displaced fractures, but this was not statistically significant. Spleen and kidney injuries were statistically significantly more frequent among the patients with the fractures of the 10th to 12th ribs. The rib fracture displacement cut-off values for pneumothorax, hemothorax, and lung injury were found to be 2.18 mm, 2.32 mm, and 2.82 mm, respectively. CONCLUSION: The presence of a displaced rib fracture is a strong predictor of intrathoracic complications. A more careful intrathoracic evaluation of rib fractures with more than 2 mm displacement will contribute to patient management.

Endovascular repair of a distal thoracic aortic transection in association with traumatic burst fracture.

We present an endovascular repair of aortic transection at distal thoracic level due to traumatic burst fracture. The association of blunt aortic transections and thoracic burst fractures is very rare. Contemporary preferred treatment approach is endovascular aortic repair, because of low mortality rates. The aortic repair procedure should be performed before spinal stabilization surgery. In this case report, we present a 49-year-old male patient with blunt traumatic descending thoracic aortic transection, treated by endovascular aortic repair. In conclusion, the emergent endovascular repair is a preferable method to treat the traumatic distal thoracic aortic transection.

Prognostic utility of pulmonary artery and ascending aorta diameters derived from computed tomography in COVID-19 patients.

AIM: Chest computed tomography (CT) imaging plays a diagnostic and prognostic role in Coronavirus disease 2019 (COVID-19) patients. This study aimed to investigate and compare predictive capacity of main pulmonary artery diameter (MPA), ascending aorta diameter (AAo), and MPA-to-AAo ratio to determine in-hospital mortality in COVID-19 patients. MATERIALS AND METHODS: This retrospective study included 255 hospitalized severe or critical COVID-19 patients. MPA was measured at the level of pulmonary artery bifurcation perpendicular to the direction of the vessel through transverse axial images and AAo was measured by using the same CT slice at its maximal diameter. MPA-to-AAo ratio was calculated by division of MPA to AAo. RESULTS: Multivariate logistic regression model yielded MPA ≥29.15 mm (OR: 4.95, 95% CI: 2.01-12.2, p = 0.001), MPA (OR: 1.28, 95% CI: 1.13-1.46, p < 0.001), AAo (OR: .90, 95% CI: .81-.99, p = 0.040), and MPA-to-AAo ratio ≥.82 (OR: 4.67, 95% CI: 1.86-11.7, p = 0.001) as independent predictors of in-hospital mortality. Time-dependent multivariate Cox-proportion regression model demonstrated MPA ≥29.15 mm (HR: 1.96, 95% CI: 1.03-3.90, p = 0.047) and MPA (HR: 1.08, 95% CI: 1.01-1.17, p = 0.048) as independent predictors of in-hospital mortality, whereas AAo and MPA-to-AAo ratio did not reach statistical significance. CONCLUSION: Pulmonary artery enlargement strongly predicts in-hospital mortality in hospitalized COVID-19 patients. MPA, which can be calculated easily from chest CT imaging, can be beneficial in the prognostication of these patients.

The effect of hepatic steatosis on COVID-19 severity: Chest computed tomography findings.

Background: The objective of our study was to investigate the location, extension and type of novel coronavirus-induced disease 2019 (COVID-19) infection involvement and hepatic steatosis on initial chest computed tomography (CT). The relationship between fatty liver and severity of the disease was also investigated by measuring the liver attenuation index (LAI). Methods: This study evaluated the chest CT images of 343 patients (201 male, mean age 48.43 years) who were confirmed to have COVID-19, using nasopharyngeal swab. The chest CTs were analyzed for laterality, number of involved lobes, diffuseness, number of lesions, and lesion types. The CT attenuation values of liver and spleen were measured, and LAI was calculated for the detection of hepatic steatosis. Univariate and multivariate logistic regression analysis were used to identify the independent early predictors for severe COVID-19. Results: There was no significant difference between genders in terms of clinical course. Liver density and LAI were significantly lower in the intensive care unit (ICU) patients. The prevalence of severe disease was higher in the patients with hepatic steatosis than in the non-steatotic group (odds ratio [OR] 3.815, 95% confidence interval [CI] 1.97-7.37, P < 0.001). After adjusting for age and comorbidities including hypertension, diabetes mellitus, coronary artery disease, chronic obstructive pulmonary disease, and chronic kidney disease, multivariate logistic regression analysis showed that non-alcoholic fatty liver disease (NAFLD) was an independent risk factor for COVID-19 severity (OR 3.935, 95% CI 1.77-8.70, P = 0.001). The optimal cut-off value for LAI was calculated as 0.5 for predicting patients who required ICU treatment. Conclusions: On the initial chest CT images of COVID-19 patients, presence of fatty liver is a strong predictor for severe disease.

Primary retrograde transpedal approach for revascularization of chronic total occlusions of the superficial femoral artery and re-route technique using percutaneous puncture for re-entry.

PURPOSE: We aimed to demonstrate the safety and feasibility of revascularization of chronic total occlusion of the superficial femoral artery (SFA) using the transpedal approach and describe a new technique called "re-route". METHODS: The study included all consecutive patients who had chronic total occlusions at the level of SFA and underwent retrograde treatment through a pedal artery intervention between September 2017 and October 2019. Balloon angioplasty was applied as the first treatment option. After angioplasty, bailout stenting was performed when necessary in patients with indications. If the common femoral artery lumen could not be reached from the SFA ostium, the re-route technique was used. Technical success was defined as revascularization with residual stenosis of less than 30%. RESULTS: Twenty-five SFAs were revascularized in 23 patients (17 males; mean age, 66±7.3 years) by angioplasty in 5 SFAs and angioplasty and stents in 20 SFAs. While the transpedal approach was applied after the failure of antegrade recanalization in three patients, it was used as the first treatment route in the remaining cases. The re-route technique was applied in 7 patients, with a 100% technical success rate. The mean follow-up was 15.3 months (range, 12-18 months). The primary patency rate was 78% at one year. CONCLUSION: The retrograde transpedal approach is a safe and successful technique for chronic total occlusion recanalization and carries a low risk of complications. In order to increase technical success, the re-route technique can be used as an alternative re-entry method.