Steven P. Rivers

Initial experience with transluminally placed endovascular grafts for the treatment of complex vascular lesions.

Objectives Complex arterial occlusive, traumatic, and aneurysmal lesions may be difficult or impossible to treat successfully by standard surgical techniques when severe medical or surgical comorbidities exist. The authors describe a single centers experience over a 2½‐year period with 96 endovascular graft procedures performed to treat 100 arterial lesions in 92 patients. Patients and Methods Thirty‐three patients had 36 large aortic and/or peripheral artery aneurysms, 48 had 53 multilevel limb‐threatening aortoiliac and/or femoropopliteal occlusive lesions, and 11 had traumatic arterial injuries (false aneurysms and arteriovenous fistulas). Endovascular grafts were placed through remote arteriotomies under local (16 [17%]), epidural (42 [43%]), or general (38 [40%]) anesthesia. Results Technical and clinical successes were achieved in 91% of the patients with aneurysms, 91% with occlusive lesions, and 100% with traumatic arterial lesions. These patients and grafts have been followed from 1 to 30 months (mean, 13 months). The primary and secondary patency rates at 18 months for aortoiliac occlusions were 77% and 95%, respectively. The 18‐month limb salvage rate was 98%. Immediately after aortic aneurysm exclusion, a total of 6 (33%) perigraft channels were detected; 3 of these closed within 8 weeks. Endovascular stented graft procedures were associated with a 10% major and a 14% minor complication rate. The overall 30‐day mortality rate for this entire series was 6%. Conclusions This initial experience with endovascular graft repair of complex arterial lesions justifies further use and careful evaluation of this technique for major arterial reconstruction.

Changing arteriosclerotic disease patterns and management strategies in lower-limb-threatening ischemia.

From January 1, 1974 to December 31, 1989, we treated 2829 patients with critical lower-extremity ischemia. In the last 5 years, 13% of patients had therapeutically significant stenoses or occlusions above and below the groin, while 35% had them at two or three levels below the inguinal ligament. Unobstructed arterial flow to the distal half of the thigh was present in 26% of patients, and 16% had unobstructed flow to the upper third of the leg with occlusions of all three leg arteries distal to this point and reconstitution of some patent named artery in the lower leg or foot. In the last 2 years, 99% of all patients with a threatened limb and without severe organic mental syndrome or midfoot gangrene were amenable to revascularization by percutaneous transluminal angioplasty (PTA), arterial bypass, or a combination of the two, although some distal arteries used for bypass insertion were heavily diseased or isolated segments without an intact plantar arch. Limb salvage was achieved and maintained in more than 90% of recent patient cohorts, with a mean procedural mortality rate of 3.3%. Recent strategies that contributed to these results include (1) distal origin short vein grafts from the below-knee popliteal or tibial arteries to an ankle or foot artery (291 cases); (2) combined PTA and bypass (245 cases); (3) more distal PTA of popliteal and tibial artery stenoses (233 cases); (4) use of in situ or ectopic reversed autogenous vein for infrapopliteal bypasses, even when vein diameter was 3 to 4 mm; (5) composite-sequential femoropopliteal-distal (PTFE/vein) bypasses; (6) reintervention when a procedure thrombosed (637 cases) or was threatened by a hemodynamically significant inflow, outflow, or graft lesion (failing graft, 252 cases); (7) frequent follow-up to detect threatening lesions before graft thrombosis occurred and to permit correction of lesions by PTA (58%) or simple reoperation; and (8) unusual approaches to all infrainguinal arteries to facilitate secondary operations, despite scarring and infection. Primary major amputation rates decreased from 41% to 5% and total amputation rates decreased from 49% to 14%. Aggressive policies to save threatened limbs thus are supported.

Basilic vein transposition: an underused autologous alternative to prosthetic dialysis angioaccess

PURPOSE Provision of lifelong angioaccess for hemodialysis generally requires multiple procedures. To extend the availability of each extremity as an access site, we have used the transposed basilic vein for fistula construction since 1988. Our purpose is to present our initial experience, with follow-up of 30 months. METHODS We have used the transposed proximal basilic vein in 65 procedures to construct an autogenous arteriovenous fistula (AVF) to the brachial artery in 58 patients without suitable superficial venous anatomy. There were 25 males and 33 females, with a mean age of 47 years (range 10 to 77). The basilic vein transposition was the initial angioaccess procedure in only 25% of cases and secondary in 75%. Three additional patients underwent exploration of an inadequate basilic vein with subsequent prosthetic grafting. RESULTS There were no operative deaths. Two postoperative complications included a wound infection and a transient steal syndrome. The actuarial life-table patency rate for all successfully completed AVFs was 49% at 30 months. Late revisions with continued patency were required in 11 cases, including repair of a focal stenosis in six, pseudoaneurysm resection in two, and thrombectomy in one. Sixty-seven percent of patients who required subsequent prosthetic grafting for a failed basilic vein AVF had an ipsilateral procedure. Patient preference for the opposite arm was the usual indication for contralateral grafting in the remainder. CONCLUSIONS The transposed basilic vein AVF was technically feasible in 95% of cases, can frequently be performed in patients with multiple previous access procedures, does not compromise the arm for future prosthetic grafting, and has a long-term patency rate that is comparable to more traditional autologous AVFs. This underused procedure should be considered before placement of polytetrafluoroethylene graft for long-term angioaccess.

Influence of vein size (diameter) on infrapopliteal reversed vein graft patency

We reviewed 239 infrapopliteal reversed greater saphenous vein graft bypasses placed for critical ischemia over a 7-year period to determine the influence of vein diameter on graft patency and limb salvage. Grafts were assigned to four groups based on the minimum external diameter measured during operation: less than 3.0 mm, n = 18; 3.0 mm, n = 59; 3.5 mm, n = 67; and greater than or equal to 4.0 mm, n = 145. A pattern of increasing graft patency and limb salvage among the four groups was noted as the minimum external diameter increased from less than 3.0 mm to greater than or equal to 4.0 mm. When compared to the larger grafts greater than or equal to 4.0 mm, primary graft patency was significantly lower both for less than 3.0 mm grafts (0% for less than 3.0 mm vs 65% for greater than or equal to 4.0 mm at 3 years, p less than 0.001) and for long (greater than 45 cm) 3.0 mm grafts (38% for long 3.0 mm vs 75% for greater than or equal to 4.0 mm at 2 years, p less than 0.005). All 3.5 mm and short (less than 45 cm) 3.0 mm grafts had patency rates similar to greater than or equal to 4.0 mm veins. Thus long 3.0 mm and all less than 3.0 mm reversed saphenous vein grafts should be considered at high risk for failure. Veins with fibrotic, thick-walled segments identified during operation (n = 19) had patency rates significantly lower than nonfibrotic veins (n = 270; p less than 0.01), and this may play a role in the failure of some less than 3.0 mm minimum external diameter vein grafts.

Quantitative assessment of outflow resistance in lower extremity arterial reconstructions

Graft patency is thought to correlate with resistance in the runoff bed or outflow resistance. However, accurate measurement of this parameter has been difficult. A simple and reproducible method for direct measurement of outflow resistance following completion of the distal anastomosis of a bypass graft has been developed. This method employs injection of a fixed amount of normal saline through the proximal end of the graft and measurement of the resulting integrated pressure increment by an analog computer. Division of this pressure integral by the volume injected is a measure of the outflow resistance expressed in resistance units (mm Hg/ml/min). The median outflow resistance in 31 femoropopliteal bypasses was 0.29 units with a range of 0.08-1.38 units. The median outflow resistance in 33 femorodistal bypasses was 0.7 units with a range of 0.18-2.34 units. All bypasses with an outflow resistance of 1.1 units or less remained patent for 3 months. There were 51 grafts in this group (30 femoropopliteal; 21 femorodistal) and their outflow resistance ranged from 0.08 to 1.1 units. All bypasses with an outflow resistance of 1.2 units or higher thrombosed within the first postoperative month. There were 13 grafts in this group (1 femoropopliteal; 12 femorodistal) and their outflow resistance ranged from 1.2 to 2.38 units. Eight of the 13 grafts that failed originally were subjected to thrombectomy, which was uniformly unsuccessful. Although this method does not yet allow bypass surgery to be denied to any patient, it does define a group of patients in whom thrombectomy will not be effective and should not be attempted.(ABSTRACT TRUNCATED AT 250 WORDS)

Limited role of arteriography in penetrating neck trauma

Of the patients with penetrating neck wounds treated between 1979 and 1986, 61 patients with 65 injuries had arteriography during their evaluation. Twenty-seven patients had stab wounds and 34 had gunshot wounds, with a relatively equal distribution between the zones of injury. Fifty-seven arteriograms were normal and six were abnormal. Of the six arteriographic defects, three were thought to be spurious on subsequent review, two were clinically insignificant, and one required surgery. No significant arterial injuries were identified by arteriography in the absence of suggestive physical findings. No major arterial injuries were discovered during neck surgery that were missed preoperatively. Neither abnormal nor normal angiograms significantly altered the course of management, including the approach to neck exploration. These data suggest that arteriography for penetrating neck trauma is usually unnecessary for observation of patients in stable condition without suggestive physical findings. Thorough neck exploration with dissection of the carotid sheath in patients with physical diagnostic criteria for surgery eliminates the need for angiography in most cases and avoids the consequences of a possible false-negative study.

Improved Strategies for Secondary Operations on Infrainguinal Arteries

Secondary interventions play an important role in achieving the ultimate goal of limb salvage after primary infrainguinal interventions fail. By employing the described strategies and principles for secondary arterial reconstructions below the inguinal ligament, good results in terms of patency of the reoperated primary reconstruction or the secondary reconstruction can be obtained with significantly augmented limb salvage at a low cost in operative morbidity and mortality. These results mandate that vascular surgeons maintain an aggressive attitude toward the use of these secondary operations when a primary procedure fails to achieve or maintain its intended goal and a patient is faced with imminent limb loss because of distal ischemia.

Successful Conservative Management of Iatrogenic Femoral Arterial Trauma

We have developed a protocol for nonoperative management of pseudoaneurysms and arteriovenous fistulas secondary to cardiac catheterization. Hemodynamically stable patients were placed at bed rest and underwent serial physical examination, hematocrit, and duplex ultrasonography for a minimum of three days prior to discharge and subsequently as outpatients. Sixteen initially stable patients out of 56 with femoral artery catheter trauma managed over a four-year period underwent deliberate conservative management. Their lesions included six arteriovenous fistulas, seven pseudoaneurysms, and three patients with both complications. All but one of the pseudoaneurysms resolved spontaneously within four weeks regardless of initial size or associated arteriovenous fistula. One patient receiving anticoagulant therapy required surgery for bleeding after a three-day period of observation of a pseudoaneurysm. Six of the nine arteriovenous fistulas also resolved within the initial period of observation. The remaining three have been followed for four to 20 months and have remained asymptomatic. Nonoperative therapy of catheter-related femoral artery trauma is both safe and effective. Conservative management avoids potential wound complications associated with dissection through surrounding hematoma as well as the additional hospitalization required for postoperative care. We recommend a period of observation for all hemodynamically stable patients with catheter-induced pseudoaneurysms and arteriovenous fistulas of the femoral vessels, with surgery reserved for hemorrhage, expanding masses, or compromised cardiac output.

Safety of peripheral vascular surgery after recent acute myocardial infarction

We have treated 30 patients requiring urgent or emergent vascular procedures in the first 6 weeks after a myocardial infarction (median 11 days) from 1977 through 1989. Forty operations were performed, including 28 lower extremity revascularizations, 10 major amputations and revisions, and two carotid endarterectomies. There were four postoperative deaths (three cardiac related) and two nonfatal reinfarctions. Cardiac complications did not correlate with age, interval from myocardial infarction to surgery within the initial 6 weeks, type of anesthesia, or complexity of operation. Twenty of 24 patients survived attempts at leg revascularization, with ultimate limb salvage in 16. Our cardiac complication rate of 17% (5/30 patients) was reasonably close to that predicted by the Goldman risk scale for classes II and III and significantly better than class IV and also better than that predicted by the Cooperman risk scale for vascular surgery, despite the more recent preoperative myocardial infarctions in our patients. We attribute our low morbidity and mortality to the extracavitary nature of the procedures and possibly to improvements in anesthetic and perioperative management. Patients requiring urgent revascularization for limb salvage should not be denied surgery on the basis of a recent myocardial infarction.

Endovascular aortounifemoral grafts and femorofemoral bypass for bilateral limb-threatening ischemia

PURPOSE Although axillobifemoral bypass procedures have a lower mortality rate than aortobifemoral bypass procedures, they are limited by decreased patency, moderate hemodynamic improvement, and the need for general anesthesia. This report describes an alternative approach to bilateral aortoiliac occlusive disease using unilateral endovascular aortofemoral bypass procedures in combination with standard femorofemoral reconstructions. METHODS Seven patients who had bilateral critical ischemia and tissue necrosis in association with severe comorbid medical illnesses underwent implantation of unilateral aortofemoral endovascular grafts, which were inserted into predilated, recanalized iliac arteries. The proximal end of the endovascular graft was fixed to the distal aorta or common iliac artery with a Palmaz stent. The distal end of the graft was suture-anastomosed to the ipsilateral patent outflow vessel, and a femorofemoral bypass procedure was then performed. RESULTS All endovascular grafts were successfully inserted through five occluded and two diffusely stenotic iliac arteries under either local (1), epidural (5), or general anesthesia (1). The mean thigh pulse volume recording amplitudes increased from 9 +/- 3 mm to 30 +/- 7 mm and from 6 +/- 2 mm to 26 +/- 4 mm ipsilateral and contralateral to the aortofemoral graft insertion, respectively. In all cases the symptoms completely resolved. Procedural complications were limited to one local wound hematoma. No graft thromboses occurred during follow-up to 28 months (mean, 17 months). CONCLUSIONS Endovascular iliac grafts in combination with standard femorofemoral bypass grafts may be an effective alternative to axillobifemoral bypass in high-risk patients who have diffuse aortoiliac occlusive disease, particularly when bilateral axillary-subclavian disease is present.