Faculty Bibliography

In vascular surgery, the gold standard for evaluation of the lower-extremity arterial tree has long been contrast arteriography (CA). Associated risks of CA are well-documented and include severe allergic reactions, arterial injury and/or hemorrhage, and contrast-induced nephropathy. Increasingly, less-invasive techniques, with fewer inherent risks for complication, are being explored as diagnostic alternatives. Magnetic resonance angiography, computed tomography angiography, and duplex arteriography, each offer distinct advantages, though are not without limitation. This review explores the indications, advantages, and disadvantages of these newer technologies and provides a comparison to CA as a means for defining the anatomic features of patients undergoing lower-extremity revascularization. This data suggests that noninvasive imaging technologies may, in the future, play an increasingly important role in the surgical evaluation of the patient with lower-extremity ischemia.

Diagnostic arteriography and balloon angioplasty of failing or nonmaturing arterio-venous (AV) access is based upon using nephrotoxic contrast. Patients not yet on dialysis with borderline renal function with nonmaturing AV accesses or ones with an allergy to contrast media present a therapeutic challenge. We have used duplex scanning as an alternative imaging modality to guide endovascular therapy in 10 cases (9 autologous and 1 prosthetic). Six target AV accesses (60%) were used for dialysis. Number of stenoses ranged from 1 to 5 per AV access. Short access sheath insertion, wire and balloon passage, and inflation were guided by duplex only. Balloon size (5-8 mm in diameter) was chosen based on duplex measurements. Cutting balloons (4 x 20 mm and 5 x 20 mm) were used for dilatation of recoiling lesions in 4 cases. One patient had a self-expanding stent placed under duplex-guidance for recoiling lesion in the junction of the brachial and axillary veins. Angioplasty of failing AV access can be performed under duplex guidance alone. Duplex guidance offers very important advantages of hemodynamic evaluation for recoiling lesions and need for stenting. Avoidance of contrast use for repair of nonfunctioning AV access can be a useful option in patients with renal failure not yet on dialysis or in cases of allergy.

In an effort to explore alternatives to contrast arteriography, we compared computed tomography angiography to contrast arteriography for defining anatomic features of patients undergoing lower extremity revascularization. From November 2003 to March 2004, 36 inpatients with chronic lower extremity ischemia underwent contrast arteriography and computed tomography angiography before undergoing lower extremity revascularization procedures. A Siemens 16 slice multiplanar computed tomography device with bolus tracking was used for these exams. The reports of these tests and images were compared prospectively, and the differences in the aorto-iliac segment, femoral-popliteal, and infrapopliteal segments were noted. The vessels were classified as mild disease (<50%), moderate disease (50%-70%), severe (71%-99%), and occluded. The studies and treatment plans based on these data were compared. The mean age was 76 +/- 12 years (SD). Indications for the procedures included gangrene (45%), ischemic ulcer (32%), rest pain (19%), and severe claudication (3%); 69% were diabetics. Accuracy of computed tomography angiography in the aorto-iliac, femoral-popliteal, and infrapopliteal segments was 100%, 81%, and 59%, respectively. Thirteen of 18 (72%) of these disagreements resulted in a different procedure than that suggested by computed tomography angiography. A review of the data obtained in this series indicated that computed tomography angiography appears to be unable to obtain adequate information in this highly selected population at our institution.

Acute limb-threatening ischemia from thrombosis may be the initial presentation of popliteal artery aneurysms (PAA) and is associated with amputation rates of 20-30%. Since contrast angiography may miss the diagnosis, the authors suspect that thrombosis of PAA may be an underappreciated cause of acute ischemia. Routine use of duplex arteriography (DA) may aid in the diagnosis and may help identify the outflow vessels with improved results. One hundred and nine patients (group 1) from 1994 to 1997 and 201 patients from 1998 to 2001 (group 2) presenting with acute limb-threatening ischemia were studied. None of the group 1 patients underwent preoperative DA and no diagnosis of acute popliteal artery aneurysm thrombosis was made. Ten patients with acute ischemia due to thrombosed popliteal artery aneurysms were identified in group 2 when preoperative DA was routinely performed. Urgent revascularization based on the results from DA was performed with use of autogenous saphenous vein in all patients. Six patients had functioning bypasses with a mean follow-up of 15.6 months. There were 3 deaths, 2 within 30 days and 1 after 2(1/2) years with functioning grafts. One patient was lost to follow-up. No major amputations were performed. Incidence of thrombosed popliteal artery aneurysms as the cause of acute limb-threatening ischemia is probably underestimated. Routine use of DA may provide the diagnosis and identifies the available outflow vessels. Contrary to previously published reports, urgent revascularization of an acutely ischemic extremity from thrombosed popliteal aneurysm can provide excellent rates of limb salvage.

The clinical importance of upper extremity deep venous thrombosis (UEDVT) has been increasingly demonstrated in recent literature. Not only has the risk of pulmonary embolism from isolated upper extremity DVT been demonstrated, but a significant associated mortality has been encountered. Examination of this group of patients has demonstrated the existence of combined upper and lower extremity deep venous thrombosis (DVT) in some patients who exhibit an even higher associated mortality. As a result of this information, it has become the standard practice at this institution to search for lower extremity DVTs in patients found to have acute thrombosis of upper extremity veins. Since January 1999, there have been a total of 227 patients diagnosed with acute UEDVT. Within this group, 211 (93%) patients had lower extremity studies; 45 of these 211 (21%) had acute lower extremity DVTs by duplex examination in addition to the upper extremity DVTs. Overall, there were 145 women, 66 men, and the average age was 70 +/-1.2 (SEM); 22 of these patients had bilateral lower extremity thrombosis (LEDVT), and 8 patients were found to have chronic thrombosis of lower extremity veins. Of the patients with bilateral upper extremity DVTs, there were 3 with bilateral LE acute DVTs. Finally, 8 of the remaining 166 patients (5%) with originally negative lower extremity studies were found to develop a thrombosis at a later date. These data serve to confirm previous studies, on a larger scale, that there should be a high index of suspicion in patients with UEDVT of a coexistent LEDVT.