Saim Yilmaz

Renal colic: comparison of spiral CT, US and IVU in the detection of ureteral calculi

The aim of our study was to compare noncontrast spiral CT, US and intravenous urography (IVU) in the evaluation of patients with renal colic for the diagnosis of ureteral calculi. During a period of 17 months, 112 patients with renal colic were examined with spiral CT, US and IVU. Fifteen patients were lost to follow-up and excluded. The remaining 97 patients were defined to be either true positive or negative for ureterolithiasis based on the follow-up data. Sensitivity, specificity, positive and negative predictive value and accuracy of spiral CT, US and IVU were determined, and secondary signs of ureteral stones and other pathologies causing renal colic detected with these modalities were noted. Of 97 patients, 64 were confirmed to have ureteral calculi based on stone recovery or urological interventions. Thirty-three patients were proved not to have ureteral calculi based on failure to recover a stone and diagnoses unrelated to ureterolithiasis. Spiral CT was found to be the best modality for depicting ureteral stones with a sensitivity of 94 % and a specificity of 97 %. For US and IVU, these figures were 19, 97, 52, and 94 %, respectively. Spiral CT is superior to US and IVU in the demonstration of ureteral calculi in patients with renal colic, but because of its high cost, higher radiation dose and high workload, it should be reserved for cases where US and IVU do not show the cause of symptoms.

Subintimal Recanalization of Long Superficial Femoral Artery Occlusions Through the Retrograde Popliteal Approach

AbstractPurpose: To investigate the value of the retrograde popliteal artery approach for the percutaneous intentional extraluminal recanalization (PIER) of long superficial femoral artery (SFA) occlusions. Methods: During a period of 17 months, PIER through ultrasound-guided retrograde popliteal artery puncture was performed for 39 long SFA occlusions in 37 patients. In six patients, six additional iliac artery stenoses were also treated via the popliteal approach. Results: The procedure was technically successful in 32 (82%) of 39 SFA occlusions; in 29, lesions were treated with balloon angioplasty alone, and in three, stents were also used. Cumulative patency rate was 66% at 6 months, 62% at 1 year, and 59% at 18 months. Additional iliac artery stenoses were successfully treated in the same session. Complications included two minor hematomas and two SFA ruptures, which required no treatment. Conclusion: PIER through retrograde popliteal puncture is a safe and effective method in the treatment of long femoropopliteal occlusions, with a high technical success, low complication rate and a reasonable short-term patency rate. The technique offers an alternative in cases where standard PIER is unsuccessful or contraindicated.

Subintimal Angioplasty of Long Superficial Femoral Artery Occlusions

PURPOSE To investigate the value of subintimal angioplasty (SA) and selective stent placement in the treatment of long (> or =15 cm) superficial femoral artery (SFA) occlusions. MATERIALS AND METHODS During a period of 4.5 years, 67 long SFA occlusions in 61 patients (52 male, 9 female) were intended to be treated with SA, either retrogradely (n = 55) or antegradely (n = 12). Postprocedural medical treatment included aspirin + ticlopidine/clopidogrel (AT/C) combination. In 25 patients warfarin was also given for 3-6 months. Patients were followed up for 1-30 months (mean 12.5 +/- 9.0 months). Hemodynamic patencies were determined with the Kaplan-Meier method, risk factors affecting patency were evaluated with the Cox model, and the patencies of the subgroups were compared with log-rank test. RESULTS Subintimal recanalization was technically successful in 59 of 67 occlusions. Technical success was 83% in the first 30 procedures, 92% in the last 37, and 100% in the last 29. Forty-six occlusions were treated with SA alone and 13 with SA and stent placement. On an intention-to-treat basis, primary patency at 6 and 12 months was 49% and 22%, respectively, and assisted primary patency at 6 and 12 months was 69% and 57%, respectively. Patency rates were not significantly different in patients with claudication versus critical limb ischemia, or in those treated with SA alone versus SA and stent placement. With the multivariate Cox model, medical treatment with AT/C combination was identified as the only significant risk factor for both primary patency and assisted primary patency. With the Kaplan-Meier analysis, primary and assisted primary patencies were significantly higher in the warfarin group than the AT/C group (P =.0002 and.0001, respectively). CONCLUSION SA is a simple and safe method with a high technical success rate in the endovascular treatment of long SFA occlusions. Long-term patency rates, however, seem unsatisfactory, despite early reports. Subintimal stent placement provides cumulative patency at least as good as SA alone. Warfarin may significantly improve both primary patency and assisted primary patency after subintimal recanalization, but even with this treatment patency rates are still lower than those reported for bypass surgery. Therefore, in long SFA occlusions, SA is not recommended for claudicants but may be valuable in patients with critical limb ischemia.

Aortoiliac Kissing Stents: Long-term Results and Analysis of Risk Factors Affecting Patency

Purpose: To present the early and long-term results of aortoiliac kissing stents implantation and evaluate the risk factors affecting patency. Methods: The data were retrospectively reviewed on 68 patients (64 men; mean age 55±11, range 32–77) who underwent kissing stents implantation during a 12-year period. The majority of patients (64, 94%) had claudication; 4 patients had rest pain. All were smokers. There were bilateral or unilateral stenoses in 42 (62%) patients, and unilateral occlusion and contralateral stenosis in 26 (38%). Lesions were treated with simultaneous implantation of self-expanding (n=52) or balloon-expandable (n=16) stents. After the procedure, patency was determined with Doppler ultrasonography or angiography at 1, 3, 6, and 12 months and annually thereafter. Primary, assisted primary, and secondary patency rates were calculated with Kaplan-Meier analysis on an intention-to-treat basis, and risk factors affecting the patency rates were determined with the Cox regression analysis. Results: All procedures were technically and clinically successful. Complications occurred in 12%, but none required surgery. The follow-up period was 35±31 months. Primary, assisted primary, and secondary patency rates, respectively, were 76%, 90%, and 94% at 1 year; 63%, 86%, and 92% at 3 years; and 63%, 64%, and 81% at 5 years. In multivariate analysis, age <50 years and presence of iliac occlusion were identified as risk factors for reduced primary and assisted primary patency; a crossed configuration of kissing stents was identified as a risk factor for reduced primary patency. Conclusion: Implantation of kissing stents is a safe and effective alternative in the treatment of aortoiliac obstructions. However, overall primary and assisted primary patency rates are inferior to those reported for surgery. Long-term patency comparable to surgery may be obtained in patients >50 years and in those without an iliac occlusion, particularly if a favorable stent configuration is achieved.

Ultrasound-Guided Retrograde Popliteal Artery Catheterization: Experience in 174 Consecutive Patients

Purpose: To assess the safety and efficacy of ultrasound (US) guidance during retrograde popliteal artery catheterization (RPAC) and identify the risk factors for late hemostasis and complications. Methods: A retrospective review was undertaken of consecutive patients who underwent grayscale US-guided RPAC during the last 8 years. Chart review identified 174 patients (150 men; mean age 61±10 years, range 37–84) with 247 iliofemoral lesions, which were treated via US-guided RPAC. Complications were classified as puncture-related versus angioplasty-related and major versus minor. Risk factors for complications and late hemostasis were evaluated with logistic and linear regression analyses, respectively. Results: All 234 US-guided RPACs were technically successful. No arteriovenous fistula (AVF) or dissection/thrombosis of the popliteal artery was observed. The mean time to hemostasis was 6.9±2.3 minutes. The presence of femoral stenosis (versus occlusion) and use of large (6 to 7-F) sheaths were significant risk factors for late hemostasis. In 234 procedures, 15 (6.4%) complications developed; 10 (4.3%) were puncture-related (3 major, 7 minor) and 5 (2.1%) were angioplasty-related (3 major, 2 minor). Intra-arterial fibrinolysis was found to be the only significant risk factor for overall and puncture-related complications. Conclusions: Our results suggest that US-guided RPAC is at least as safe as other RPAC methods described in the literature. In contrast to generally held concerns, hemostasis is easy to obtain, and multiple punctures and the use of large sheaths appear safe. These results should be taken into consideration during the selection of an access site for endovascular treatment of superficial femoral artery and tandem iliofemoral lesions.

Primary Stenting of Focal Atherosclerotic Infrarenal Aortic Stenoses: Long-Term Results in 13 Patients and a Literature Review

We conducted this study to investigate the value of primary stent implantation for the endovascular treatment of focal atherosclerotic stenoses of the infrarenal abdominal aorta. The data of 13 patients with a localized complex infrarenal aortic stenosis who underwent primary stenting was retrospectively evaluated. The patients (6 females, 7 males) had a mean age of 57.3 ± 9.1 years (mean ± SD). In all patients, the aortic diameter was measured on CT sections, and a self-expanding endoprosthesis was primarily implanted followed by dilatation with single or double balloons. In 3 patients, additional distal stenoses were also endovascularly treated. The procedure was technically successful in all patients. No complications occurred except for 2 minor groin hematomas. During the 43 ± 23 months (mean ± SD) follow-up (range: 12–96 months), all stented aortic segments remained patent. Clinical patency was lost in 4 patients, which was due to atherosclerosis or restenosis distal to the aorta. In view of the excellent early and long-term results, we believe that primary stenting should be considered the first line treatment in properly selected patients with focal atherosclerotic infrarenal stenoses of the abdominal aorta.

Subintimal versus Intraluminal Recanalization of Chronic Iliac Occlusions

Purpose: To present our experience with subintimal recanalization of chronic iliac occlusions and retrospectively compare the results of this technique with those of standard intraluminal recanalization Methods: A retrospective review was conducted of 98 patients (91 men; mean age 61±10 years, range 37–77) with unilateral chronic iliac occlusions who underwent standard intraluminal recanalization or subintimal recanalization if intraluminal wire passage failed. The technical success, complications, and patency rates were statistically compared between groups. Results: In 59 (60%) of 98 patients, the occlusions were successfully crossed with ipsilateral intraluminal recanalization, while failure of intraluminal recanalization in the remaining 39 led to attempted subintimal recanalization (ipsilateral in 17 and antegrade-retrograde in 22). Overall, ipsilateral intraluminal recanalization was technically successful in 56 (57%) of 98 patients; subintimal recanalization was successful in 35 (90%) of 39 patients. Technical success was only 29% in 17 patients who underwent subintimal recanalization via an ipsilateral retrograde approach. During a follow of 27±16 months, primary and assisted primary patencies were not significantly different between the patients treated with intraluminal versus subintimal recanalization (p = 0.81 and 0.64, respectively). Conclusions: Subintimal recanalization is a safe and effective supplement to standard intraluminal recanalization techniques in the endovascular treatment of chronic iliac occlusions. Because of the poor outcome associated with the ipsilateral route, subintimal recanalization of these lesions should preferably be performed via a combined antegrade-retrograde approach.

Transvenous Embolization and Stent Placement for an Internal Iliac Arteriovenous Fistula with Central Iliac Vein Occlusion

The authors present a case of traumatic arteriovenous fistula of the internal iliac vessels treated with attempted surgical ligation of the common iliac artery and external iliac artery. The fistula persisted after the operation, and because the patient received no further treatment for the following 6 years, a venous outflow occlusion also developed as a result of high-flow angiopathy. Because the arterial route was eliminated at previous surgery, the fistula and venous occlusion were percutaneously treated via a transvenous approach.

Anteroposterior diameter of the vertebral canal in cervical region: Comparison of anatomical, computed tomographic, and plain film measurements

The purpose was to compare the computed tomographic and plain film measurements with those of anatomical specimens to determine the antero‐posterior diameter of the spinal canal in cervical region. Antero‐posterior diameters of 75 cervical vertebral canals (15 sets of C3–C7) were measured anatomically at two different levels. Computed tomographic and plain film measurements were also obtained at the corresponding levels. Considering anatomical measurements as the gold standard, plain film and computed tomographic measurements were statistically compared. Interobserver and intraobserver differences were also evaluated. At the uppermost pedicle levels, there was no statistically significant difference between plain films and anatomical measurements, a good correlation. However, at lowermost pedicle level there was a statistically significant difference between plain films and anatomical measurements but not between tomographic and anatomical measurements. Our results suggest that plain films can accurately estimate cervical spinal canal mid‐sagittal diameter at the uppermost pedicle level and be used as a first step examination for the evaluation of cervical spinal stenoses. Clin. Anat. 14:15–18, 2001.

Bilateral transpopliteal approach for treatment of complex SFA and iliac occlusions

Abstract. We present a successful case of percutaneous intentional extraluminal recanalization (PIER) of bilateral long superficial femoral artery (SFA) occlusions and a long iliac artery occlusion through ultrasound-guided retrograde popliteal artery punctures. To our knowledge, PIER of SFA occlusions via popliteal approach has been reported in only three cases, and subintimal recanalization of combined SFA and iliac occlusions has not been reported.