This report is one of a series of Reporting Standards generated by an Ad Hoc Committee of the Joint Councils of the Society for Vascular Surgery and International Society for Cardiovascular Surgery, North American Chapter. It is meant to address the needs of vascular surgery practitioners in their assessment of the merits of arterial prostheses, including methods of evaluation and expected performance. Although the standards described here are not mandatory, the Committee urges that at least minimally acceptable criteria be adopted by both manufacturers and regulatory authorities. BACKGROUND AND RATIONALE The rationale for this standard is to provide a document for use and reference by vascular surgeons regarding the evaluation of safety, efficacy, and expected performance of arterial prostheses. It will outline both the minimum expected or acceptable and the optimum possible results. Although there is a parallel effort by the American Association for Medical Instrumentation (AAMI) to generate a vascular prostheses standard, this latter standard is primarily for use by graft manufacturers; this document, as stated above, will be primarily for the vascular surgical community. Currently there is no official document in existence directed to surgeons who use prostheses. It is hoped that by reference to this standard, any potential user will be able to understand more about

Three hundred twenty-five cases of spontaneous aortic dissection seen at two institutions between 1965 and 1986 were reviewed to assess the incidence, morbid sequelae, and specific management of aortic branch compromise. Noncardiac vascular complications occurred in 33% of the study group, and in these patients the overall mortality rate (51%) was significantly (p less than 0.001) higher than in patients without (29%) such complications. Although aortic rupture was the strongest correlate of mortality (90%), death specifically related to vascular occlusion was common when such occlusion occurred in the carotid, mesenteric, and renal circulation. There was a strong correlation between stroke and carotid occlusion (22/26 cases), yet specific carotid revascularization was only used during the chronic phase of the disease. Similarly, peripheral operation was ineffective in reducing the mortality rate in the setting of mesenteric (87%) and renal (50%) ischemia. Fifteen patients required either fenestration or graft replacement of the abdominal aorta for acute obstruction, rupture, or chronic aneurysm development. Thirty-eight patients (12%) demonstrated some degree of lower extremity ischemia, and one third of these required a direct approach on the abdominal aorta or iliofemoral segments to restore circulation. Selected patients with acute aortic dissection may require peripheral vascular operation in accordance with a treatment strategy that directs initial attention to the immediate life-threatening complications.

The hypothesis that a mismatch in compliance between a vascular graft and its host artery is detrimental to graft patency was tested by implanting paired arterial autografts, prepared with differential glutaraldehyde fixation of carotid arteries in the femoral arteries of dogs. These grafts differed only in circumferential compliance: they were 100% (compliant) vs. 40% (stiff) as compliant as the host artery. Their flow surfaces were equivalent, as determined by physicochemical measurements and scanning electron microscopy; both lacked viable cells, as determined by in vitro cell culture. In 14 dogs, eight stiff and two compliant grafts became occluded within 3 months, the latter doing so within 24 hours after their contralateral counterparts. Cumulative patencies were 85% and 37% for compliant and stiff grafts, respectively (p less than 0.05) and 100% and 43%, excluding the two dogs with bilateral graft failures (p less than 0.01). We conclude that even with near optimal flow surfaces, compliance mismatch is deleterious to graft patency.

Although an aberrant right subclavian artery arising from the proximal portion of the descending thoracic aorta is the most common aortic arch anomaly, few patients have clinical symptoms directly attributable to it. When symptoms do occur they are usually causally related to aneurysmal or occlusive sequelae of atherosclerotic disease of the anomalous vessel. More unusual manifestations peculiar to the anomalous artery include aneurysmal degeneration of the origin of the vessel from the aortic arch, with its inherent risk of rupture, or symptoms of compression of the trachea or more commonly the esophagus by the anomalous vessel as it traverses the superior mediastinum. In patients with symptoms a variety of operative approaches and management strategies have been used. Our recent experience with treatment of two patients with clinical symptoms caused by an aberrant right subclavian artery illustrate the varied surgical options and prompted a review of the surgical management of this unusual anomaly.

Although unusual, innominate artery lesions may present challenging problems. To classify the wide spectrum of problems requiring operation and elucidate certain principles of management, a series of 71 patients undergoing operation for innominate artery problems over a 20-year period was reviewed retrospectively. Occlusive disease (37 patients) was most common, usually presenting with neurologic or ocular symptoms. Other lesions included innominate aneurysm (three), aortic dissection involving the innominate artery (three), traumatic injuries (five), tracheoinnominate fistula (10), anomalous origin or tortuosity causing tracheal compression (six), involvement in mediastinal tumor or scar (six), and thromboembolus (one). The type of operative repair and mortality rate varied with the nature of the lesion. Overall 38 patients underwent transsternal repair, whereas 12 had extrathoracic bypass, 16 resection and oversewing, and five a pexy procedure. For occlusive disease, direct repair via median sternotomy gave best long-term results with an acceptable mortality rate (3.4%). Shunting was not required. Extrathoracic grafting proved safe but less durable and should be reserved for high-risk patients or special circumstances.