Graham Roche-Nagle

Radiofrequency In Situ Fenestration for Aortic Arch Vessels During Thoracic Endovascular Repair

Purpose: To report the first clinical application of a novel technique using radiofrequency puncture to create retrograde in situ fenestrations during thoracic endovascular aortic repair (TEVAR). Methods: Between June 2011 and December 2013, 40 TEVAR procedures were performed in our facility, including 10 cases in which in situ fenestration was planned. Two thoracic stent-graft models were deployed: the Valiant (n=5) and the Zenith TX2 (n=5). A 0.035-inch PowerWire radiofrequency guidewire delivered from a brachial approach was used to fenestrate the grafts covering a left subclavian artery (LSA) in 9 cases and a left common carotid artery in one. The fenestrations were serially dilated to 6 mm, and self-expanding Advanta V12 covered stents were positioned in the target arteries. Results: Technical success was achieved in 6 of the 10 planned cases. Of the remaining 4 cases, stent-grafts were deployed in zone 3 in 2 cases (one received a chimney to the LSA). Another stent-graft was deployed in zone 2 without endoleak after fenestration was abandoned (the LSA had good filling via the vertebral artery). In the last case, the fenestration was unsuccessful in double-layered (proximal extension overlap) stent-grafts; a carotid-axillary bypass was required. There were no fenestration-related complications, but overall surgical complications included a case of paraparesis that resolved following spinal drainage and a death from a preexisting aortoesophageal fistula. There were no postoperative strokes. All fenestrations remained patent, and there were no endoleaks at a mean 12-month follow-up (range 1–33). Conclusion: Radiofrequency puncture is a viable alternative to needle or laser punctures for in situ fenestration during TEVAR. Early clinical results suggest technical feasibility and acceptable early outcomes.

Acute thrombosis of an abdominal aortic aneurysm presenting as cauda equina syndrome

Acute aortic occlusion is an uncommon vascular emergency that can present with predominantly neurologic symptoms owing to spinal cord ischemia. We describe a 62-year-old woman who experienced acute thrombosis of an abdominal aortic aneurysm that initially presented as cauda equina syndrome. She was treated operatively with an axillary bifemoral bypass. Our case report is followed by a discussion of acute aortic occlusion.

Neoadjuvant Aortic Endografting

The advent and success of endovascular repair of abdominal aneurysms led to the development of catheter-based techniques to treat thoracic aortic pathology. Such diseases, including thoracic aortic aneurysms, acute and chronic type B dissections, penetrating aortic ulcers, and traumatic aortic transection, challenge surgeons to perform complex open operative repairs in high-risk patients. The minimally invasive nature of thoracic endografting provides an attractive alternative therapy. We present two cases of covered stent grafts deployed in the thoracic aorta to perform resection of the aortic wall infiltrated by malignancy in order to avoid a major vascular intervention and a traditional vascular graft interposition. This may become a potential new utility for aortic endografts.

Endovascular treatment of a bleeding secondary aortoenteric fistula in a high-risk patient.

We report a patient with life-threatening gastrointestinal bleeding caused by a secondary aortoenteric fistula (AEF). Because the patient had severe medical comorbidities, an endovascular approach was chosen for hemorrhage control. Endovascular treatment of aortoenteric fistula provides another treatment option that may be particularly valuable in patients whose comorbidities would preclude open repair.

Increasing angulation decreases measured aortic stent graft pullout forces

OBJECTIVE Experimentally measured pullout forces for stent grafts (SGs) are used in clinical discussions and as reference values in bench studies and computer simulations. Previous values of these forces are available from studies in which the SG was pulled out in the straight caudal direction. However, clinical and numerical studies have suggested that displacement forces acting on SGs are directed more anteriorly. The objective of this study was to measure pullout forces as a function of angulation and to test the hypothesis that pullout forces decrease with increasing angulation. METHODS Six different SGs (Bolton Treovance, Cook Zenith Flex, Cook Zenith LP, Medtronic Endurant, Medtronic Talent, and Vascutek Anaconda) were deployed in fresh bovine aortas, then pulled out by an electronic motor at 1 mm/s, while tension force was measured continuously with a digital load cell. The SG off-axis angulation was changed from 0 to 90 degrees in increments of 10 degrees. The test system was submerged in a custom-built temperature-controlled saline bath at 37°C. At least three tests were performed for each device at each angle (with the exception of the Cook Zenith Flex, which experienced plastic deformation of its barbs after a single test per device). Each aortic specimen was used only once and then discarded. Hand-sutured graft anastomoses were also tested at 0 degrees to provide a reference value. RESULTS A total of 374 pullout tests were performed for the SGs and anastomoses. Sixty-four tests were excluded because of failure of the aorta or apparatus before device pullout. The remaining 310 tests showed pullout forces that demonstrated a decrease in the average pullout force for all six devices from 0 to 90 degrees (Bolton Treovance from 39.3 N to 23.9 N; Cook Zenith Flex from 59.8 N to 48.9 N; Cook Zenith LP from 50.3 N to 41.8 N; Medtronic Endurant from 29.9 N to 25.8 N; Medtronic Talent from 6.0 N to 5.5 N; and Vascutek Anaconda from 37.0 N to 30.3 N). For reference, the mean pullout force for the hand-sutured anastomoses was 63 N. CONCLUSIONS This study reports for the first time the change in pullout force with angulation, showing a general pullout force decrease with increasing angle. With a larger number of samples than in previous studies, our results provide updated benchmark data that can be used for clinical discussions, computational and experimental studies, and future device design.

Popliteal vein aneurysm.

Although popliteal venous aneurysms are uncommon, they are also potentially fatal because they can cause a pulmonary embolism. The authors report a case of a popliteal vein aneurysm in a healthy, asymptomatic 32-year-old patient as well as a review of the literature. Popliteal venous aneurysms are a rare but treatable cause of recurrent pulmonary embolism, with their true incidence probably being underestimated. Whenever possible, we recommend early surgical repair of both symptomatic and asymptomatic popliteal venous aneurysms because they are associated with an ill-defined risk of pulmonary embolism and death if left untreated.

Pseudoaneurysm of the Brachial Artery Following Humeral Fracture

The frequency of peripheral artery aneurysms in the upper extremities is less than in the lower extremities. Diagnosis and surgical treatment are important because upper extremity aneurysms can severely compromise the function of a limb and possibly lead to the loss of an arm or fingers. Very rarely, posttraumatic upper extremity pseudoaneurysms show symptoms after a long period of time. Diagnosis can be made on review of the patients history and a physical examination. Surgical reconstruction is the preferred treatment for such patients. We present a case of a brachial artery pseudoaneurysm following humeral fracture.

Heparin-induced thrombocytopenia in the presence of a heparin-bonded bypass graft.

The use of prosthetic grafts in below-knee bypasses may be necessary in patients with no available autologous vein and critical limb ischemia not amenable to angioplasty. Such conduits, however, have generally yielded disappointing results. A new, heparin-bonded, expanded polytetrafluoroethylene graft (Gore Propaten vascular graft) designed to provide resistance to thrombosis may be associated with decreased early graft failure and increased patency. A concern with exposure to heparin, and therefore heparin-bonded prostheses, is the development of heparin-induced thrombocytopenia (HIT). Although rare, this requires prompt graft removal. We present a case to highlight this serious complication and review the literature on this topic.

Symptomatic Thoracic Aorta Mural Thrombus

Cases of mural aortic arch thromboses are generally associated with diffuse atherosclerosis of the aortic arch and have primarily been detected in elderly patients. However, the presence of mural thrombi in the aortic arch in young patients without diffuse atherosclerosis has rarely been reported. We describe a case of a hypercoagulable young patient with arterial embolism in whom investigations revealed a mural pedunculated aortic arch thrombosis without clear diffuse atherosclerotic lesions.

Predictors of hospital readmissions after lower extremity amputations in Canada.

OBJECTIVE To describe the factors associated with early (≤30 days) and late (31-365 days) hospital readmissions after lower extremity amputations in Canada. METHODS A retrospective cohort study was carried out for all Canadian adults who underwent elective lower extremity amputations in the years 2006 to 2008 for nontraumatic indications. Patients were identified from the Canadian Institute for Health Informations Discharge Abstract Database, which includes all hospital admissions across Canada, with the exception of the Province of Quebec. RESULTS During the study period, 3823 patients underwent lower limb amputations (major amputations = 95%) and 2116 were readmitted at least once (55.4%). Of those patients, 1112 (29.1%) were readmitted within 30 days (mean = 5.0 ± 8.3 days after discharge) and 1004 (26.3%) were readmitted between 31 and 365 days (mean = 151.4 ± 95.9 days after discharge). Stump complications accounted for 13% and 10% of early and late readmissions, respectively. Stump revision surgery was performed in 301 readmitted patients (7.9%). Predictors of early readmission included amputation by a vascular surgeon (odds ratio, 1.6; 95% confidence interval, 1.3-1.9), female sex (odds ratio, 1.2; 95% confidence interval, 1.1-1.5), and a short (<7 day) admission (odds ratio, 1.7; 95% confidence interval, 1.4-2.1). Predictors of late readmission included a longer (≥7 days) admission (odds ratio, 1.5; 95% confidence interval, 1.2-1.8), discharge to a long-term care facility (odds ratio, 3.3; 95% confidence interval, 2.7-3.9), and home discharge with community support (odds ratio, 2.3; 95% confidence interval, 1.8-2.9). CONCLUSIONS Half of patients who underwent lower extremity amputations were readmitted to the hospital within 1 year. Markers of patient dependence (long hospitalization, discharge to long-term care facility) predict late readmission.