Theodoros Kostas

Computational Evaluation of Aortic Aneurysm Rupture Risk: What Have We Learned So Far?

In current clinical practice, aneurysm diameter is one of the primary criteria used to decide when to treat a patient with an abdominal aortic aneurysm (AAA). It has been shown that simple association of aneurysm diameter with the probability of rupture is not sufficient, and other parameters may also play a role in causing or predisposing to AAA rupture. Peak wall stress (PWS), intraluminal thrombus (ILT), and AAA wall mechanics are the factors most implicated with rupture risk and have been studied by computational risk evaluation techniques. The objective of this review is to examine these factors that have been found to influence AAA rupture. The prediction rate of rupture among computational models depends on the level of model complexity and the predictive value of the biomechanical parameters used to assess risk, such as PWS, distribution of ILT, wall strength, and the site of rupture. There is a need for simpler geometric analogues, including geometric parameters (e.g., lumen tortuosity and neck length and angulation) that correlate well with PWS, conjugated with clinical risk factors for constructing rupture risk predictive models. Such models should be supported by novel imaging techniques to provide the required patient-specific data and validated through large, prospective clinical trials.

Preliminary experience with cutting balloon angioplasty for iliac artery in-stent restenosis.

Purpose: To report our preliminary experience using cutting balloon angioplasty (CBA) in symptomatic iliac artery in-stent restenosis (ISR). Methods: Fourteen cases of hemodynamically significant iliac artery ISR (4 common and 10 external) were treated in 12 men (mean age 64 years, range 55–75). Of the 14 stents involved, 8 were balloon-expandable models and 6 were self-expanding. All patients had symptomatic deterioration of at least 1 clinical category over an average period of 50.2 months (range 6–120) post stenting. The mean length of ISR was 11.9 mm (range 2–48), and the average stenosis was 75.4% (range 52%–98%). Nine ISR lesions were focal (<10 mm), 4 were diffuse (>10 mm), and 1 extended outside the stent margins. Results: CBA was performed after conventional angioplasty failure in 7 lesions and as a primary treatment method in 7 lesions. Single (9 focal lesions) or multiple overlapping (5 diffuse or proliferative lesions) inflations were performed using 6-×10-mm (1 lesion), 7-×10-mm (3 lesions), and 8-×10-mm (10 lesions) devices. There was 1 contained rupture treated with a covered stent. In the remainder of the cases, the cutting balloons allowed successful treatment without further stent implantation. During a mean follow-up of 23.6 months (range 12–60), no patient showed clinical deterioration, and no recurrent ISR was detected with color duplex. Conclusion: CBA shows high immediate technical and midterm clinical success in symptomatic iliac artery ISR.

Suspected acute deep vein thrombosis of the lower limb in outpatients: considerations for optimal diagnostic approach.

The objective of this study was to review our diagnostic approach using color duplex scanning (CDS) in the management of symptomatic outpatients with suspected lower limb deep venous thrombosis (DVT). CDS was carried out in 315 consecutive outpatients with unilateral symptoms consistent with DVT. Both limbs were assessed in 205 patients. Other pathology was routinely sought when the symptomatic limb was free of thrombosis. Acute DVT was present in 25% (76/315) of the symptomatic limbs, and in only 8% it was confined to calf veins. Other pathology was detected in 90 limbs (28%). Swelling with or without pain was associated with DVT in 44% and 10%, respectively. The time elapsed between the onset of symptoms and CDS was 3 days (range 1–6 days). DVT in the contralateral asymptomatic limb was present in 5 (9%) of the 56 patients with DVT in the symptomatic limb. In the absence of DVT in the symptomatic limb, the contralateral asymptomatic limb was free of thrombosis. Clinical diagnosis of DVT in outpatients was unreliable. CDS revealed that only one-fourth of the symptomatic limbs had DVT, and other pathology mimicking DVT was present in 28%. CDS is a useful tool that offers a prompt, efficient diagnosis. Investigation of the contralateral asymptomatic limb seems to be necessary only when DVT is found in the symptomatic limb.

Vibrational angioplasty in recanalization of chronic femoropopliteal arterial occlusions: single center experience.

PURPOSE This prospective study aims to present the overall success rate, safety and long-term outcome of vibrational angioplasty technique, in the treatment of chronic total femoropopliteal occlusions in our institute. METHODS Between October 2000 and December 2008, patients with chronic total femoropoliteal arterial occlusions, treated with vibrational angioplasty during the same session after a failed attempt with conventional recanalization technique, were included. Patients follow up included serial ankle-brachial index measurements and arterial duplex ultrasound examinations at 1, 3, 6, 12, 24, 36 and 48 months. RESULTS Twenty-seven patients (16 males and 11 females) and twenty-eight lesions were included in our study. Twenty-five lesions (89.3%) were successfully recanalized. Pain relief was noticed in twenty-one cases. From ten lesions with tissue loss (ulcer or gangrene) in successfully recanalized occlusions, six healed without major, or minor amputation. One non-healing amputation stump was healed after recanalization, without further complications. Four limbs underwent amputation (one minor and three major) despite successful recanalization, however all had an excellent healing of the amputation stump without further complications. The Kaplan-Meier test demonstrated 90%, 85% and 70% amputation-free survival rate at 12, 24 and 36 months, respectively. No major or minor complications were encountered. CONCLUSIONS Vibrational angioplasty is a safe, effective and durable endovascular technique for the treatment of chronic total occlusions in patients with limb ischemia that would be difficult to recanalize using conventional intraluminal techniques.

Use of the Trellis™ Peripheral Infusion System for Enhancement of rt-PA Thrombolysis in Acute Lower Limb Ischemia

The Trellis™ Peripheral Infusion System is an over-the-wire 0.035″ guidewire compatible device, designed to isolate a region of the peripheral vasculature to allow for lytic drug infusion and dispersion. We used it successfully through a percutaneous approach in two cases of acute thrombosis of a native lower limb artery. The total amount of rt-PA used was 12 and 9 mg, respectively and was delivered through bolus injections obviating the need for a supplementary continuous infusion of the agent. The time for dissolution of thrombus was 45 and 35 minutes, respectively. No complications were observed.

Venous hypertension due to outflow stenosis in a Gracz arteriovenous fistula: correction with distal cephalic transposition

hypertension. Accordingly, surgical repair was performed under local anesthesia. Since the basilic vein presented no stenosis in the entire upper limb and flow persisted down into the hand via the cephalic vein, we decided to dissect and fully mobilize the cephalic vein in the lower part of the forearm (Fig. 2a, continuous line), so that a sufficient length (Fig. 2a, dotted line and Fig. 2b) could loop back to be anastomosed to the basilic vein in the middle part of the forearm (Fig. 2a), in an end-to-side fashion (Fig. 2c), with subsequent ligation of the peripheral segment of the basilic vein. Immediate post-operative improvement of the hand was noted with normal appearance and absence of heaviness and pain (Fig. 3). The functioning status of the access remains satisfactory after one year. Ligation or use of the PV in a side-to-end anastomosis with the brachial artery has been suggested as a means to avoid steal syndrome and venous hypertension by interrupting the connection between the deep and superficial venous systems of the upper limb, provided that the central outflow tract remains patent and well functioning. In our case, occlusion of the cephalic vein centrally to the AVF caused flow overload in the forearm cephalic vein with resultant peripheral hypertension. The cephalic vein carries only a few valves in the forearm, mainly in the elbow, just before the junction with the median cubital vein (3). Interestingly, 10% of these have been reported as valve preparations and thus incomplete, rendering them amenable to reversal, leading to poor apposition of the leaflets of the already few valves. Furthermore, the cephalic vein in the forearm has very few perforating veins, mostly located in the distal third of the forearm and almost a third of them connected to the muscles (4). Therefore, flow overload in the forearm cephalic vein could alone lead to peripheral venous hypertension as in our case. Small segments of synthetic grafts have been reported to bridge autologous vein segments for the revision of failing or failed AVFs in the upper limb (1,5). In our case, we chose to dissect free an adequate length of the dilated cephalic vein to loop back to the ulnar side for anastomosis with the basilic vein. In this way, a) the flow Venous hypertension due to outflow stenosis in a Gracz arteriovenous fistula: correction with distal cephalic transposition

A delayed diagnosis that altered the professional orientation of an athlete with upper limb chronic arterial embolization

Summary Background Vascular disorders of the upper extremity in young and physically active patients present a complex and challenging problem for the treating physician. Initial presentation may often be subtle and the consequences of misdiagnosis, delayed diagnosis or mistreatment can be severe. Case Report In this report, we discuss a case of a young woman with chronic upper limb ischemia due to an arterial thoracic outlet syndrome in whom even though symptoms persisted over a number of years during which she frequently sought medical consultation, remained undiagnosed until finally presenting with limb-threatening ischemia. Furthermore, due to this delay, the patient was forced to withdraw from her professional carrier in athletics. Conclusions A thoughtful and through approach combining the history, physical findings, and use of appropriate diagnostic aids will provide the physician and patient with the greatest opportunity for a satisfactory outcome. Furthermore, a delay in definitive treatment may not only cause health deterioration, but may also incur social, economic and occupational consequences.

Endovascular treatment of a ruptured profunda femoral artery branch after fogarty thrombectomy of a femoro-femoral crossover arterial graft: a case report and review of the literature.

We present a very rare case of a life-threatening rupture of a profunda femoral artery distal branch after a Fogarty thrombectomy of a thrombosed crossover synthetic graft between the ipsilateral common femoral artery and a contralateral iliac-popliteal graft; the bleeding profunda femoral artery branch was successfully embolized with metallic coils through the axillary artery approach.