Endovascular Recanalization of the Chronically Occluded Native Superficial Artery After Failed Bypass Graft: Midterm Results.

PURPOSE: To evaluate the safety, effectiveness, and outcomes of endovascular recanalization of chronic total occlusion (CTO) of the superficial femoral artery (SFA) in patients with critical limb ischemia (CLI) after failed surgical bypass graft. METHODS: Endovascular recanalization of SFA CTO was performed for 26 consecutive CLI patients with failed bypass grafts from 2016 to 2020. Patient demographics, bypass and lesion characteristics, procedural data, technical, and clinical outcomes were evaluated. RESULTS: The technical success rate was 96.2% (25/26). Retrograde arterial access was used in 16 (61.6%) patients. Additional tibial and iliac angioplasty was performed in 15 and 2 patients, respectively. Fifteen complications occurred in 10 patients, including thrombosis, embolism, vessel rupture, dissection, arteriovenous fistula, and pseudoaneurysm. Pain relief and wound healing were achieved in 22 patients. The primary, assisted primary, and secondary patency rates were 95.5%, 100%, and 100% at 6 months, 81.8%, 95.5%, and 100% at 12 months, and 76.7%, 82.7%, and 87.5% at 24 months, respectively. By univariate analysis, hyperlipidemia (hazard ratio = 7.82; 95% CI: 1.27-48.04, P = .026) was found to be the only significant risk factor related to primary patency loss. Amputation-free survival and limb salvage rates were 100% and 100% at 6 months, 100% and 100% at 12 months, and 87.1% and 93.8% at 24 months, respectively. CONCLUSIONS: Endovascular recanalization of SFA CTO in CLI patients with graft failures is effective with high technical success rates. Acceptable limb salvage and amputation-free survival rates make this technique a reasonable alternative to repeat surgery for high-risk patients.

Endovascular recanalization and remodeling of abdominal aorta stent graft chronic total occlusion after failed extra-anatomic bypass surgery.

OBJECTIVES: Chronic total occlusion (CTO) of the EVAR graft is a rare and serious complication. Traditionally, surgical intervention with prosthetic graft replacement or bypass graft implantation is performed. However, there are limited data in endovascular era. METHODS: We present a case of a 68-year-old male with a history of late EVAR graft occlusion treated with multiple surgical interventions (femorofemoral crossover, extra-anatomic bypass surgery, and thrombectomy) five years ago. Color Doppler ultrasound (CDUS) and computed tomography (CT) angiography revealed thrombosis of the entire bypass graft. Endovascular recanalization and remodeling of the abdominal stent graft CTO was performed with a combination of bare stents and stent grafts. Rupture of the stent graft occurred on the right limb. A second covered stent was placed. RESULTS: At 12-month follow-up, the patient was symptom free. Color Doppler ultrasound surveillance showed patent aortic stent graft and downstream arteries. CONCLUSIONS: Endovascular recanalization of aortic stent graft CTO is a viable option in patients with failed bypass graft.

Retrograde Pedal Access via Occluded Arteries in Endovascular Treatment of Critical Limb Ischemia.

PURPOSE: To evaluate the feasibility and technical outcomes of retrograde access via occluded pedal arteries in endovascular treatment of critical limb ischemia (CLI) when the conventional antegrade approach fails. MATERIALS AND METHODS: One hundred fifty-one patients with CLI (age 69 y ± 10.5; 116 men) who were not surgical candidates and were treated via retrograde pedal access between January 2016 and January 2018 were evaluated retrospectively. Seventy patients in whom retrograde access was performed through occluded arteries constituted the occluded group, and 81 patients who were treated via retrograde access from patent arteries constituted the nonoccluded group. Pedal access success, lesion crossing success, angiographic success, overall technical success, and procedure-related complications were evaluated and compared between groups. RESULTS: Pedal access success (74 of 78 vs 83 of 87 attempts; P = .873) and lesion crossing success (64 of 78 vs 77 of 87 lesions; P = .340) were comparable between subgroups. Angiographic success (54 of 78 vs 77 of 87 lesions; P = .012) and overall technical success (48 of 70 vs 72 of 81 patients; P = .004) rates were lower in the occluded group. Procedure-related complications were similar between groups (P = .096). CONCLUSIONS: Retrograde pedal access from occluded pedal arteries is a feasible option when an antegrade approach fails in endovascular treatment of CLI. Although it has lower technical success, its use enables angiosome-directed therapy and has the potential to improve the outcomes of the procedure.

Transhepatic Pharmacomechanical Thrombectomy of Symptomatic Acute Noncirrhotic, Nonmalignant Portomesenteric Venous Thrombosis: Midterm Results.

OBJECTIVE. The purpose of this study was to evaluate the safety and efficacy of transhepatic pharmacomechanical thrombectomy of symptomatic acute portomesenteric venous thrombosis. MATERIALS AND METHODS. Transhepatic pharmacomechanical thrombectomy (catheter-directed thrombolysis with mechanical thrombectomy) was performed in the treatment of nine patients with symptomatic acute noncirrhotic, nonmalignant porto-mesenteric venous thrombosis. The medical records, imaging examinations, technique of transhepatic pharmacomechanical thrombectomy, and clinical outcomes were reviewed. RESULTS. The mean follow-up period was 23.1 months (range, 8-34) months. Successful recanalization of the portomesenteric venous thrombosis, restoration of hepatopetal portal flow, clinically significant improvement in the signs and symptoms of acute mesenteric ischemia, and prevention of bowel resection were achieved in all patients. The most frequent minor complication (in three patients) was minor hemorrhage through the transhepatic access track. No procedure-related major complications occurred during hospitalization. No patient had rethrombosis or complications related to portal hypertension due to portomesenteric venous thrombosis. One patient died of massive pulmonary embolism on the 7th day after treatment. Cavernous transformation of the right portal vein occurred in one patient. CONCLUSION. Transhepatic pharmacomechanical thrombectomy is a safe and effective method of treatment of symptomatic acute portomesenteric venous thrombosis and prevention of bowel infarction.

Endovascular Treatment of Critical Limb Ischemia in Buerger Disease (Thromboangiitis Obliterans) With Midterm Follow-Up: A Viable Option When Bypass Surgery Is Not Feasible.

OBJECTIVE. Thromboangiitis obliterans (TAO) is an occlusive inflammatory disease affecting small- and medium-sized vessels that causes decrease in life quality and eventually limb loss. The only proven treatment method is smoking cessation, but it may be insufficient for limb salvage in patients with critical limb ischemia. In this single-center retrospective study, the feasibility and efficiency of endovascular treatment in TAO were evaluated. MATERIALS AND METHODS. After approval of the local institutional review board, 41 patients who underwent endovascular treatment of TAO between January 2014 and June 2019 were evaluated retrospectively. Technical success and procedure-related complications were recorded. Decrease in Rutherford classification score, relief of pain, and wound healing were evaluated to determine clinical success. Primary patency, limb salvage rate, and amputation-free survival were also evaluated. RESULTS. A total of 45 limbs were treated during the study period. Technical success was achieved in 82.2% of procedures. Mean follow-up was 29.8 months. Clinical improvement was achieved in 35 limbs. Three patients underwent major amputation and 12 patients underwent minor amputation. Amputation-free survival and limb salvage were both 93.3% at both 1 and 2 years. Reintervention was performed in 14 patients because of occlusion and clinical relapsing of the symptoms. CONCLUSION. Endovascular treatment of TAO is feasible, has a potential to prevent limb amputation in patients with critical limb ischemia, and has acceptable technical success and limb salvage rates. Because there is no consensus in treatment of TAO, prospective comparative studies are needed to determine the effectiveness of an endovascular approach.

Percutaneous Intraductal Microwave Ablation of Malignant Biliary Strictures: Initial Experience.

OBJECTIVE. Metallic stenting of malignant biliary strictures is the preferred method of palliation, because most patients present when the condition is inoperable. Most metallic stents, however, are occluded 6-8 months after deployment. Intraductal radiofrequency ablation has been used in previous studies to improve stent patency. The purpose of this study was to assess a single-center experience with percutaneous intraductal microwave ablation of malignant biliary strictures. MATERIALS AND METHODS. In this retrospective case series study, data on 12 patients with malignant biliary obstruction who underwent percutaneous intraductal microwave ablation followed by metallic stenting were evaluated. Ablation procedures were performed with generator frequencies of 902-928 MHz, power set at 6-10 W, and ablation time of 60-90 seconds in a temperature-controlled manner with target temperature set at 80°C. RESULTS. Causes of malignant biliary obstruction were pancreatic carcinoma in four patients, gastric antrum carcinoma in three, cholangiocarcinoma in two, metastasis in two, and gallbladder carcinoma in one patient. Percutaneous intraductal microwave ablation and metallic stenting were performed successfully in all patients. There was no procedural mortality or major complication. The most common minor complication was abdominal pain. Biliary decompression was achieved in all patients at the end of the first month. The mean follow-up time was 9.4 months. The median primary stent patency period was 231 days. There were two stent occlusions due to sludge formation, and two patients died during follow-up. CONCLUSION. Percutaneous intraductal microwave ablation of malignant biliary strictures is safe and feasible. Prospective randomized controlled studies with long-term results are warranted to determine the effectiveness of this technique in lengthening the stent patency period.

Intraarterial polidocanol injection for the treatment of peripheral arteriovenous malformations.

PURPOSE: The purpose of this study was to investigate the efficacy and safety of intraarterial transcatheter administration of polidocanol as an alternative treatment for peripheral arteriovenous malformations (AVMs). METHODS: The study comprised 10 patients (six males and four females) with a mean age of 28.8 years (range 8-52 years). All patients had trunk or extremity AVMs. Following the administration of general anesthesia or intravenous (IV) sedation, the patients underwent staged intraarterial polidocanol sclerotherapy with or without additional embolizations for their AVMs. The administration of polidocanol was executed by intraarterial infusion through a microcatheter or by direct percutaneous entry into the nidus under ultrasound guidance. RESULTS: A total of 19 sessions were accomplished in 10 patients. Polidocanol was used alone in six of the 19 sessions. In 13 sessions, polidocanol was used in combination with another agent (including n-butyl cyanoacrylate (NBCA), lipiodol, and ethanol) and/or coils. In two sessions, polidocanol was administered percutaneously under ultrasound guidance directly into the nidus documented by arteriography. No major complications occurred. CONCLUSION: Intraarterial transcatheter administration of polidocanol alone or in combination with other agents is a safe and effective alternative treatment for peripheral AVMs.

Bilateral fused os intermetatarseum presenting as dorsal foot pain: a case report.

PURPOSE: Os intermetatarseum is a rare accessory bone of the forefoot and usually situated between the base of the first and second metatarsals. Most of the cases are asymptomatic and diagnosed incidentally. Here, we report a rare form of os intermetatarseum presented with bilateral dorsal foot pain and to the authors' knowledge, it is the first case which includes computerized tomography (CT) and magnetic resonance imaging (MRI) findings. METHODS: A 23-year-old male complained of localized bump at the dorsum of the both feet underwent bilateral anteroposterior foot radiograms which was unremarkable and then CT and MRI were performed. RESULTS: MRI of both feet demonstrated osseous structures in relation with medial os cuneiforme. Computerized tomography demonstrated bilateral os intermetatarsea fused with medial os cuneiforme. CONCLUSIONS: It is important for radiologist to know that os intermetatarseum can be presented as dorsal foot pain. Due to its position, it is difficult to demonstrate os intermetatarseum in plain radiographs, CT and MRI should be performed in clinically suggestive cases.

The Feasibility of Low-dose Chest CT Acquisition Protocol for the Imaging of COVID-19 Pneumonia.

OBJECTIVE: This study aimed to investigate the feasibility of low-dose chest CT acquisition protocol for the imaging of COVID 19 disease or suspects of this disease in adults. METHODS: In this retrospective case-control study, the study group consisted of 141 patients who were imaged with low dose chest CT acquisition protocol. The control group consisted of 92 patients who were imaged with standard protocol. Anteroposterior and lateral diameters of chest, effective diameter and scan length, qualitative and quantitative noise levels, volumetric CT dose index (CTDIvol), dose length product (DLP), and size-specific dose estimations were compared between groups. RESULTS: Radiation dose reduction by nearly 90% (CTDIvol and DLP values 1.06 mGy and 40.3 mGy.cm vs. 8.07 mGy and 330 mGy.cm, respectively; p < 0.001) was achieved with the use of low-dose acquisition chest CT protocol. Despite higher image noise with low-dose acquisition protocol, no significant effect on diagnostic confidence was encountered. Cardiac and diaphragm movement-related artifacts were similar in both groups (p=0.275). Interobserver agreement was very good in terms of diagnostic confidence assessment. CONCLUSION: For the imaging of COVID-19 pneumonia or suspects of this disease in adults, lowdose chest CT acquisition protocol provides remarkable radiation dose reduction without adversely affecting image quality and diagnostic confidence.

Radiation doses from head, neck, chest and abdominal CT examinations: an institutional dose report.

PURPOSE: We aimed to obtain typical values for head, neck, chest, and abdominal computed tomography (CT) examinations from routine patients in 2018, and to review our data with national and international diagnostic reference levels (DRLs). METHODS: Single-phase head, neck, chest, and abdominal CT scans of adults performed in 64-slice CT in 2018 were included in this study. Radiation dose parameters of CT scans were obtained from the picture archiving and communication system of our hospital. Volumetric CT dose index (CTDIvol) and dose length product (DLP) values were recorded. Effective dose (ED) and scan length was calculated. A 16 cm diameter phantom is referenced for head CT, and 32 cm diameter phantom is referenced for neck, chest, and abdominal CT. Descriptive statistics of the variables were given according to the normality testing. RESULTS: Median CTDIvol value was 53 mGy for the head, 13.1 mGy for the neck, 8.3 mGy for the chest, and 8.6 mGy for the abdomen. Median DLP value was 988 mGy.cm for the head, 299 mGy.cm for the neck, 314 mGy.cm for the chest, and 457 mGy.cm for the abdomen. Median ED value was 2.07 mSv for the head, 1.76 mSv for the neck, 4.4 mSv for the chest, and 6.8 mSv for the abdomen. Considering national DRLs, median CTDIvol values of head, chest, and abdomen were lower, whereas median DLP and ED values of head and chest were higher. For the abdomen, the median DLP and ED values were lower. CONCLUSION: Overall radiation dose parameters obtained in this study points out the need for optimization of head CT examinations in our institution.

The Prevalence of Open and Closed Posterior Superior Iliac Spine.

AIM: To determine the prevalence of open and closed posterior superior iliac spine (PSIS) using lower abdominal computed tomography (CT) examinations. MATERIAL AND METHODS: Eight hundred and fifty (M/F:464/386) adult patients who underwent lower abdominal CT between January 2018 and December 2018 were evaluated retrospectively. One radiologist reviewed CT images of patient pelvises to assess the presence of open and closed PSIS. RESULTS: The mean age of all patients was 52.7 ± 18 years. Of the 850 patients, 522 (61.5%) had open PSIS, while 328 (38.5%) had closed PSIS. The distribution of open and closed PSIS by gender was 57.5% and 42.5% in males and 66% and 34% in females, respectively. CONCLUSION: Overall, open PSIS is more common than closed PSIS. The closed PSIS is seen more often in males than in females. If an anteromedial sacral (S)-1 screw direction is chosen for posterior fusion with rod-screw fixation, it is essential to obtain CT images for evaluation of PSIS.

Percutaneous endobiliary ablation of malignant biliary strictures with a novel temperature-controlled radiofrequency ablation device.

PURPOSE: We aimed to determine the safety and effectiveness of percutaneous endobiliary radiofrequency ablation of malignant biliary obstructions with a temperature-controlled radiofrequency ablation device. METHODS: In this single center retrospective study, a total of 62 consecutive patients with malignant biliary obstruction were evaluated. Thirty patients who underwent endobiliary radiofrequency ablation with metallic stent placement were in the study group and 32 patients who underwent only metallic stenting were in the control group. Outcomes of this study were technical success, complications related to the procedure, stent patency, and overall survival. RESULTS: All procedures were technically successful in both groups. There was no procedure-related mortality in either group. Procedural complication rates were similar between the groups. Although statistically not significant, the only two major complications (hemobilia requiring endovascular treatment) were in the control group. Median primary stent patency was significantly longer in the study group than in the control group (223 days vs. 158 days; P = 0.016). Median survival rates were also longer in the study group (246 days vs. 198 days; P = 0.004). CONCLUSION: Percutaneous endobiliary radiofrequency ablation is safe and feasible with this novel radiofrequency ablation device in patients with malignant biliary obstruction. Percutaneous endobiliary radiofrequency ablation has a potential to improve both stent patency and survival.

Effect of Visceral, Subcutaneous and Retroperitoneal Adipose Tissue on Renal Function After Living Donor Nephrectomy: A Retrospective Analysis of 69 Cases.

PURPOSE: Recent studies reported that the presence of metabolic syndrome is closely correlated with impaired kidney function after living donor nephrectomy. Since the measurement of body mass index cannot differentiate the amount of body adipose tissue from total body weight, body mass index is not a reliable parameter for determining metabolic syndrome. In the present study, we investigated the correlation between body adipose tissue and kidney function recovery following living donor nephrectomy. MATERIALS AND METHODS: The patients who underwent living kidney donor nephrectomy consequently from July 2016 through December 2017 were enrolled in the study. We preoperatively measured the visceral (VAdT), retroperitoneal (RPAdT), and subcutaneous (SCAdT) adipose tissue volume by a computed tomography scan. Body mass index, adipose tissue measurements, and postoperative estimated glomerular filtration rate (eGFR) were evaluated. RESULTS: The decrease between preoperative eGFR, and the first day, the first month and the sixth month eGFR after surgery were statistically significant (P = .001; P = .001; P = .001, respectively). The negative correlation between VAdT/SCAdT measurements and changes in eGFR at the first and the sixth postoperative month compared to preoperative eGFR were statistically significant (P = .049; P = .041, respectively). Additionally, RPAdT measurements and changes in eGFR at the first and the sixth postoperative month compared to preoperative eGFR (decreasing as RPAdT value increased) were statistically significant (P = .035; P = .026, respectively). CONCLUSION: According to a preoperative computed tomography scan, VAdT, RPAdT, and VAdT-to-SAdT ratio can predict impaired kidney function recovery. Furthermore, RPAdT measurement is a new variable to predict the impaired kidney function after living donor nephrectomy.

Castleman's disease presenting with mechanical intestinal obstruction: A rare case.

Castleman's disease (CD) is a lymphoproliferative disorder and the occurrence of CD in the small bowel is rare. In this study, we present one case of CD causing mechanical intestinal obstruction due to involvement of terminal ileum. A 50-year-old man was admitted to the hospital with signs and symptoms of mechanical intestinal obstruction without history previous surgery. After examination and obtaining abdominal computed tomography, diagnosis of mechanical intestinal obstruction was reached and emergency surgery was performed with a median incision. On abdominal exploration a tumor like mass that also held distal small intestine mesentery, and ileocecal valve causing complet intestinal obstruction was observed. Ileocecal resection and ileocolonic anastomosis were performed. CD is a rare entity and should be kept in mind during the differential diagnosis of mechanical intestinal obstruction provided that wall thickening in terminal ileum mimicking mass, and accompanying enlargement mesenteric lymph nodes observed during preoperative investigations or intraoperative exploration.

The feasibility of high-pitch acquisition protocol for imaging of the pediatric abdomen by dual-source CT.

PURPOSE: To investigate feasibility of high-pitch acquisition protocol for imaging of pediatric abdomen. MATERIALS AND METHODS: The study group consisted of 90 patients scanned with high-pitch acquisition protocol (pitch = 3) by 64-slice dual-source CT (DSCT) scanner. Fifty-four patients scanned with standard protocol (pitch = 1.5) by 16-slice single-source CT scanner comprised the control group. Anteroposterior and lateral diameters of abdomen, effective diameter, scan time and length, qualitative and quantitative noise levels, volumetric CT dose index (CTDIvol), dose length product (DLP), and size-specific dose estimations were compared between groups. RESULTS: The mean scan time of high-pitch CT protocol was shorter than control protocol (1.66 ± 0.31 vs. 4.1 ± 0.75 s; p < 0.001). The high-pitch protocol reduced the radiation dose by 48% (CTDIvol and DLP values 0.94 mGy and 32.2 mGy-cm vs. 1.59 mGy and 61.5 mGy-cm; p < 0.001, respectively). Although image noise was higher with high-pitch acquisition, there was no significant effect on diagnostic confidence. Voluntary and involuntary artifacts were less frequent in high-pitch protocol (p < 0.001). Interobserver agreement was moderate in terms of artifact and very good in terms of diagnostic confidence assessment. CONCLUSION: High-pitch acquisition protocol by DSCT yields significant radiation dose reduction without compromising image quality and diagnostic confidence for pediatric abdomen imaging.

Comparison of image quality and radiation dose between prospectively ECG-triggered and retrospectively ECG-gated CT angiography: Establishing heart rate cut-off values in first-generation dual-source CT.

OBJECTIVE: To evaluate radiation dose and image quality of prospectively electrocardiography (ECG)-triggered and retrospectively ECG-gated coronary computed tomography (CT) angiography and to establish cut-off values of heart rates (HRs) for each technique in first-generation dual-source CT. METHODS: A total of 200 consecutive patients with suspected coronary artery disease were accepted into the study. Patients were selected randomly for each technique (prospective triggering group n=99, mean age 55.85±10.74 and retrospective gating group n=101, mean age 53.38±11.58). Two independent radiologists scored coronary artery segments for image quality using a 5-point scale. Also, attenuation values of each coronary artery segment and dose-length product values were measured. For each technique, cut-off HR values were determined for the best image quality. RESULTS: Mean image quality scores and attenuation values were found to be higher in the prospective triggering group (p<0.05). Mean radiation dose was 73% lower for the prospective triggering group (p<0.01). The cut-off HR values for good image quality scores were ≤67 beats per minute (bpm) and ≤80 bpm for the prospective triggering and retrospective gating groups, respectively (p<0.05). Increased HR (≥68 and ≥81 bpm, respectively) had negative effects on image quality (p<0.05). CONCLUSION: The prospective ECG triggering technique has better image quality scores than retrospective ECG gating, particularly in patients who have an HR of less than 68 bpm. Also, a 73% radiation dose reduction can be achieved with prospective ECG triggering. In patients with higher heart rates, retrospective ECG gating is recommended.

Gadolinium leakage into subarachnoid space and cystic metastases.

Subarachnoid space (SAS) and cystic metastatic lesions of brain parenchyma appear hypointense on fluid-attenuated inversion-recovery (FLAIR) and T1-weighted magnetic resonance imaging (MRI) unless there is a hemorrhage or elevated protein content. Otherwise, delayed enhancement and accumulation of contrast media in SAS or cyst of metastases should be considered. We present hyperintense SAS and cystic brain metastases of lung cancer on FLAIR and T1-weighted MRI, respectively, in a patient who had been previously given contrast media for imaging of spinal metastases and had mildly impaired renal functions, and discuss the relevant literature.