Faculty Bibliography

OBJECTIVE: The role of percutaneous angioplasty and stenting of carotid bifurcation lesions has been limited by its potential for producing embolic debris. We evaluated the efficacy of a proximal occlusion catheter (POC) in the prevention of embolic events during carotid artery stenting. In addition, pressure measurements relevant to the clinical application of this device were obtained from 10 patients undergoing carotid endarterectomy. METHODS: The POC is a guiding catheter with an occlusion balloon attached on the outside of the catheter at its distal end. Occlusion of the common carotid artery (CCA) was achieved by inflating the balloon while access to carotid bifurcation lesions was obtained through the inner lumen. The POC was inserted in the CCA of 10 dogs via the femoral artery. The side port of the POC was connected to a sheath placed in the femoral vein, thereby creating an external arteriovenous shunt. Ten artificial radiopaque particles simulating embolic particles and contrast agent were introduced in the CCA and monitored fluoroscopically. As a control, the same procedure was performed with a standard guiding catheter without an occlusion balloon. In 10 patients undergoing carotid endarterectomy, the internal carotid artery (ICA) and external carotid artery stump pressures and the pressure in the internal jugular vein were measured. RESULTS: Without the external arteriovenous shunt, in all animals there was prograde flow in the distal CCA despite CCA occlusion. This flow was derived from the thyroid artery. However, once the arteriovenous shunt was activated, reversal of flow in the distal CCA was achieved in each animal, and all the artificial particles were recovered from the side port of the POC. In the control group, each particle embolized to the brain (100%, P <.01). In the patients, the mean stump pressures in the ICA and external carotid artery and the jugular vein pressure were 51.8 +/- 14.2, 62.2 +/- 15.1, and 6.5 +/- 3.5 mm Hg, respectively. In each case, the jugular vein pressure was the lowest among the three. CONCLUSIONS: Obtaining proximal CCA control by inflating the POC does not sufficiently prevent embolization. However, reversal of flow in the ICA can always be created with the external shunt, which effectively prevents embolization. Thus, POC may markedly lower procedural stroke rates during carotid artery stenting. The ability of POC to prevent embolization before crossing the lesion with a guidewire may be an important advantage over other distal protection devices

OBJECTIVE: Carotid bifurcation angioplasty and stenting (CBAS) has generated controversy and widely divergent opinions about its current therapeutic role. To resolve differences and establish a unified view of CBAS' present role, a consensus conference of 17 experts, world opinion leaders from five countries, was held on November 21, 1999. METHODS: These 17 participants had previously answered 18 key questions on current CBAS issues. At the conference these 18 questions and participants' answers were discussed and in some cases modified to determine points of agreement (consensus), near consensus, (prevailing opinion), or divided opinion (disagreement). RESULTS: Conference discussion added two modified questions, placing a total of 20 key questions before the participants, representing four specialties (interventional radiology, seven; vascular surgery, six; interventional cardiology, three; neurosurgery, one). It is interesting that consensus was reached on the answers to 11 (55%) of 20 of the questions, and near consensus was reached on answers to 6 (30%) of 20 of the questions. Only with the answers to three (15%) of the questions was there persisting controversy. Moreover, both these differences and areas of agreement crossed specialty lines.Consensus Conclusions: CBAS should not currently undergo widespread practice, which should await results of randomized trials. CBAS is currently appropriate treatment for patients at high risk in experienced centers. CBAS is not generally appropriate for patients at low risk. Neurorescue skills should be available if CBAS is performed. When cerebral protection devices are available, they should be used for CBAS. Adequate stents and technology for performing CBAS currently exist. There were divergent opinions regarding the proportions of patients presently acceptable for CBAS treatment (<5% to 100%, mean 44%) and best treated by CBAS (<3% to 100%, mean 34%). These and other consensus conclusions will help physicians in all specialties deal with CBAS in a rational way rather than by being guided by unsubstantiated claims

OBJECTIVE: Hypogastric artery (HA) occlusion during aortic aneurysm repair has been associated with considerable morbidity. We analyzed the consequences of interrupting one or both HAs in the standard surgical or endovascular treatment of aortoiliac aneurysms (AIAs). METHODS: From 1992 to 2000, 154 patients with abdominal aortic aneurysms (n = 66), iliac aneurysms (n = 28), or AIAs (n = 60) required interruption of one (n = 134) or both (n = 20) HAs as part of their endovascular (n = 107) or open repair (n = 47). Endovascular treatment was performed with a variety of industry- or surgeon-made grafts in combination with coil embolization of the HAs. The standard surgical techniques included oversewing or excluding the origins of the HAs and extending the prosthetic graft to the external iliac or femoral artery. RESULTS: There were no cases of buttock necrosis, ischemic colitis requiring laparotomy, or death when one or both HAs were interrupted. Persistent buttock claudication occurred after 16 (12%) of the unilateral and 2 (11%) of the bilateral HA interruptions. Impotence occurred in 7 (9%) of the unilateral and 2 (13%) of the bilateral HA interruptions. Minor neurologic deficits of the lower extremity were observed in 2 (1.5%) of the patients with unilateral HA interruption. CONCLUSIONS: Although HA flow should be preserved if possible, selective interruption of one or both HAs can usually be accomplished safely during endovascular and open repair of anatomically challenging AIAs. We believe other comorbid factors such as shock, distal embolization, or the failure to preserve collateral branches from the external iliac and femoral arteries may have contributed to the morbidity in other reports of HA interruption

OBJECTIVE: Precise diameter changes in iliac artery aneurysms (IAAs) after endovascular graft (EVG) repair are yet to be determined. This report describes the midterm size changes in isolated IAAs 13 to 72 months after treatment with an EVG. METHODS: From January 1993 to April 1999, 31 patients with 35 true isolated IAAs (32 common iliac and 3 hypogastric) had these lesions treated with EVGs and coil embolization of the hypogastric artery or its branches. The EVG used in this study consisted of a balloon-expandable stent attached to a polytetrafluoroethylene graft. Contrast-enhanced spiral computed tomographic scans were performed at 3- to 6-month intervals to follow the aneurysms for change in diameter and endoleaks. RESULTS: Thirty patients had a decrease in the size of their iliac aneurysms with EVG repair. All EVGs remained patent. All patients, except for one, were followed up for 13 to 72 months (mean, 31 months). The pretreatment aneurysm size ranged from 2.5 to 11.0 cm in diameter (mean, 4.6 +/- 1.62 cm). After EVG treatment, the aneurysms ranged from 2.0 to 8.0 cm in diameter (mean, 3.8 +/- 1.36 cm). The change in aneurysm diameter ranged from 0.5 to 3.1 cm (mean, 1.1 +/- 0.62 cm) with an average change of -0.516 +/- 0.01 cm/y for the first year. Five patients died of their intercurrent medical conditions during the follow-up period. One of the patients had a new endoleak and an increase in common iliac aneurysm size 18 months after EVG treatment, despite an early contrast-enhanced computed tomographic scan that showed no endoleak. This patient's aneurysm ruptured, and a standard open surgical repair was successfully performed. Another patient had a decrease in hypogastric aneurysm size after EVG treatment and no radiographic evidence of an endoleak, but eventually the aneurysm ruptured. He was successfully treated with a standard open surgical repair. CONCLUSIONS: EVGs can be an effective treatment for isolated IAAs. Properly treated with EVGs, IAAs decrease in size. The enlargement of an IAA, even if no endoleak can be detected, appears to be an ominous sign suggestive of an impending rupture. IAAs that enlarge should be closely evaluated for an endoleak. If an endoleak is detected, it should be eliminated if possible. If an endoleak cannot be found, open surgical repair should be considered

Neurologic deficits secondary to embolic events have been the most significant concern regarding carotid bifurcation stenting. Experimental studies utilizing human carotid plaques have shown that embolic particles were released from all specimens. In addition, transcranial Doppler studies have confirmed the fact that multiple emboli are released during each case. Preliminary experiences with the use of cerebral protection devices for carotid stenting have shown encouraging results with embolic particles recovered from each case, although these experiences have also revealed some of the down sides of its use. The present article provides the rationale for routine use of these protection devices and also reviews various protection devices, some of which are currently undergoing clinical trials

BACKGROUND: This article described a 7-year experience with endovascular graft for the tratment of aortoiliac aneurysms and other arterial lesions. METHODS: Four hundred and seventy-two grafts of various types have been placed in 283 patients. RESULTS: Short and mid-term results in these patients suggest that endovascular grafts may provide better treatment for central artery injuries and some iliac and aortoiliac aneurysms, particularly in high-risk patients and those with previous aortoiliac surgery. CONCLUSIONS: In other circumstance, long-term evaluation will be required to determine the effectiveness and limitations of these endovascular grafts

OBJECTIVE: To report a new management approach for the treatment of ruptured aortoiliac aneurysms. METHODS: This approach includes hypotensive hemostasis, minimizing fluid resuscitation, and allowing the systolic blood pressure to fall to 50 mmHg. Under local anesthesia, a transbrachial guidewire was placed under fluoroscopic control in the supraceliac aorta. A 40-mm balloon catheter was inserted over this guidewire and inflated only if the blood pressure was less than 50 mmHg, before or after the induction of anesthesia. Fluoroscopic angiography was used to determine the suitability for endovascular graft repair. When possible, a prepared, 'one-size-fits-most' endovascular aortounifemoral stented PTFE graft was used, combined with occlusion of the contralateral common iliac artery and femorofemoral bypass. If the patient's anatomy was unsuitable for endovascular graft repair, standard open repair was performed using proximal balloon control as needed. RESULTS: Twenty-five patients with ruptured aortoiliac aneurysms (18 aortic, 7 iliac) were managed using this approach. Balloon inflation for proximal control was required in nine of the 25 patients. Twenty patients were treated with endovascular grafts. Five patients required open repair. The ruptured aneurysm was excluded in all 25 patients; 23 survived. Two deaths occurred in patients who received endovascular grafts with serious comorbidities. The surviving patients who received endovascular grafts had a median hospital stay of 6 days, and the preoperative symptoms resolved in all patients. CONCLUSIONS: Hypotensive hemostasis is usually an effective means to provide time for balloon placement and often for endovascular graft insertion. With appropriate preparation and planning, many if not most patients with ruptured aneurysms can be treated by endovascular grafts. Proximal balloon control is not required often but may, when needed, be an invaluable adjunct to both endovascular graft and open repairs. The use of endovascular grafts and this approach using other image-guided catheter-based adjuncts appear to improve treatment outcomes for patients with ruptured aortoiliac aneurysms