Should all spontaneous popliteal aneurysms be operated on?

Operative treatment of spontaneous popliteal aneurysms (S.P.As) is occasionally disappointing. In order to determine the criteria for operation we analyzed retrospectively the fate of 77 S.P.As in 52 patients (mean age, 66 +/- 10 years). S.P.As were divided into 3 groups according to initial symptoms: group I, asymptomatic or mild symptoms, group II, rest pain or toe gangrene, group III, severe ischemia or foot gangrene. Patency rate of arterial reconstruction in groups I, II, III were respectively 83%, 43%, 36%. The course of S.P.As of group I that were not initially operated was not significantly different compared to those operated on, as long as they were frequently reviewed and operated on expeditionaly in cases of complications. The nature of the arterial substitute was the second contributing factor. Quality of run-off had no influence in groups I and II, but was determinant in group III. A good general condition was essential for survival. Operative indications of S.P.As is considered according to classification into 3 groups. Group I: bypass is mandatory, except when the general condition of the patient is poor or when a bad run-off is associated with an unavailable vein. Group II: bypass should be attempted whenever a distal arterial segment seems suitable. Otherwise lumbar sympathectomy may sometimes save a limb. Group III: bypass should be attempted only when the run-off is sufficient and when the tissue damage seems reversible. In the other cases, primary amputation is safer.