Impact of nonoperative therapy on the clinical management of peripheral arterial disease

Nonoperative therapy includes conservative noninterventional modalities and the endovascular interventional modalities of percutaneous transluminal angioplasty and a variety of laser systems and atherectomy devices. The role and impact of all nonoperative treatments are considered in the perspectives of the natural history of lower-extremity arteriosclerosis and its present surgical (operative) treatment. Nonoperative treatments may replace and/or facilitate surgical treatment in operative candidates. Nonoperative methods may also justify treatment in patients who cannot or should not be subjected to surgery. Facts and opinions relating to these uses of nonoperative treatments are presented, and the qualifications and credentialing of individuals who should be treating patients with lower-extremity ischemia resulting from peripheral arteriosclerosis are discussed.

Analysis of high-frequency rotational angioplasty-induced echo contrast

During high-frequency rotational angioplasty (HFRA), myocardial contrast enhancement (echo contrast) was observed by means of two-dimensional echocardiography. In order to evaluate the echo contrast produced by HFRA, an in vitro experimental model was built using a cylinder with the HFRA catheter scanned in a water bath. The cylinder was filled with blood, mineral water, and distilled water. With a 2.5-MHz transducer, echograms were recorded and analyzed by video intensitometer, and the maximum intensity IUmax and persistence time P were calculated. Rotation frequencies of 20,000-200,000 rpm with 2.0--mm burrs and times of 10 s were tested. In another model, hyperbaric conditions for the same media were produced. The influence of debris from arterioscleroic plaque and of hematocrit on echo contrast intensity were also analyzed. The effect of HFRA on hemolysis (LDH, free hemoglobin) within 10 s and temperature were also measured. The contrast effect was transient, depending on the rotation frequency. In blood, it appeared at 20,000 rpm (IUmax at 200,000 rpm: 237 IU), in mineral water at 40,000 rpm (IUmax 165 IU), and in distilled water at 80,000 rpm (IUmax 72 IU). Persistence time was measured up to about a half-minute. Echo contrast production was reduced at 0.5 bar and fully suppressed at 2.5 bar. Debris increased contrast intensity from about 219 IU to 225 IU (at 160,000 rpm). In blood IUmax decreased from 227 IU to 97 IU by lowering the hematocrit from 44.2% to 3.6%.(ABSTRACT TRUNCATED AT 250 WORDS)

Percutaneous extraction of fractured guidewire from distal right coronary artery

The incidence of retained hardware components in the coronary artery tree is likely to parallel the growing number and types of percutaneous coronary revascularization procedures being performed. Management has extended from the conservative option of simply leaving behind the retained components to the more aggressive approach of surgical removal. A percutaneous method is described herein which offers the interventional cardiologist an alternative method of managing patients with retained wire fragments contained entirely in the coronary artery.

Angiographic follow-up and clinical outcome of 126 patients after percutaneous directional atherectomy (Simpson AtheroCath) for occlusive peripheral vascular disease

Angiographic and clinical follow-up data were obtained in 115/126 patients who underwent directional atherectomy for peripheral vascular disease; of the 126, ten were excluded for appropriate reasons and one was lost to follow-up. Thus, 115/116 successful atherectomy patients (99%) had follow-up of 182/213 lesions (86%): 74 patients (64%) with angiography (mean time 5.4 mon), and 41 patients (36%) clinically. One hundred twenty-eight of 183 lesions (70%) had angiographic follow-up; the lesion recurrence as a stenosis or as an occlusion was 53%. Lesion distribution did not differ between angiography and clinical follow-up groups: nearly 85% were within the superficial femoral or popliteal arteries. Despite data stratification, angiographic follow-up indicated that patients after successful directional atherectomy, at a mean follow-up time of 5 mos, have more than a 50% lesion recurrence rate. Although directional atherectomy (Simpson AtheroCath) utilizing present techniques has excellent primary success and acceptable complication rates, angiographic follow-up statistics are bothersome.

The Simpson atherectomy catheter in the management of complete obstructions

The Simpson atherectomy catheter has been used successfully to recanalise eleven complete occlusions of the iliac and femoropopliteal arteries. Atherectomy and angioplasty were used in combination in 8 cases. Following atherectomy, all patients showed clinical improvement. Distal pulses returned in 7; rest pain and/or claudication disappeared in the other 4. Ischaemic ulcers healed in the 2 affected patients. Overall, ankle-arm indices (AAI) improved by an average of 0.43, with the improvement being greatest (0.55) in patients in whom the lumen was recanalised to within 91-100% of the native luminal diameter. Seven patients have remained with stable AAI values and without change in their clinical status at 18 months follow-up.

[Percutaneous atherectomy of the pelvic and leg arteries]

Percutaneous atherectomy, using a Simpson atherectomy catheter, was performed in 70 patients (43 men, 27 women) whose average age was 72 years (range 42 to 87 years). Between June 1988 and July 1989 all patients with disease in suitable localisations were treated in this way. The Doppler sonographic index before treatment was 0.6 (SD = 0.15), after treatment 0.89 (SD = 0.13). Recurrence was 21% after six months and 29% after twelve months. Atherectomy is superior to balloon dilation in the treatment of solitary eccentric stenoses of the superficial femoral artery and of the popliteal artery.

Thrombectomy for late graft limb occlusion: our experience in 182 consecutive cases

Late occlusion of an aortofemoral bypass graft is usually caused by fibrointimal hyperplasia or progressive atherosclerosis. Several surgical approaches have been advocated in order to minimize the operative risk, to correct the impaired inflow and to provide a satisfactory outflow. In the last 16 years, in the Institute of Vascular Surgery and Angiology of the University of Milan, we have operated upon 182 consecutive thrombosed grafts. Inflow was restored by performing a graft limb thrombectomy using a Fogarty balloon catheter and simultaneously employing an endarterectomy ring stripper to dislodge tenaciously adherent fibrinous material and thrombotic plug. As the superficial femoral artery was generally occluded, usually a good outflow was achieved by profundaplasty in 101 cases (55.5%) or direct bypass (interposition graft), to a more distal segment of the profunda femoris artery in 55 cases (30.2%). Concomitant popliteal or tibial revascularization was done in the remaining 26 cases (14.3%) when pre-operative or intra-operative findings suggested an inadequate collateral network through the profunda femoris artery. Early re-occlusion, which occurred in 14 cases (7.6%), generally due to insufficient outflow, was corrected by additional intervention in 7 cases (3.8%), while 7 legs were amputated for extensive atherosclerotic disease. Six patients died giving a mortality rate of 3.3%. This low rate in a high risk population is probably related to our policy of operating under loco-regional anaesthesia. Long term results, with a patency rate of 62.0% at 3 years and 60.2% at 5 years (life table method), prove that this operation is a durable procedure for correction of graft limb thrombosis.

Directional coronary atherectomy for the treatment of coronary lesions with abnormal contour

Directional coronary atherectomy is a newly developed percutaneous transluminal procedure which excises and removes obstructive tissue from coronary arteries or saphenous vein grafts. This procedure was performed on 47 lesions with abnormal contour; 24 ulcerative lesions, 10 lesions with dissection, 7 flap-like lesions and 6 lesions with aneurysm dilatation. Overall success rate was 89%; 96% in ulcerative lesions, 70% in lesions with dissection, 86% in flap-like lesions and 100% in lesions with aneurysmal dilatation. Complications with this procedure were as follows: Vessel occlusion in 2 patients (4.5%), perforation in 1 patient (2.3%), and guiding catheter induced dissection in 1 patient (2.3%). Coronary artery bypass surgery was required in 4 patients (9.4%) for these complications. Of these, 3 patients had lesions with dissections prior to the atherectomy procedure. The success rate for lesions with abnormal contour was similar to those of 270 lesions with normal contour. In conclusion, directional coronary atherectomy is a safe and effective procedure for lesions with abnormal contour, however, outcome of a lesion with dissection is suboptimal and it needs to be approached cautiously.

Carotid endarterectomy

A technique for carotid endarterectomy done under general anesthesia features the routine use of a straight shunt, precise removal of all plaque and shreds of media, and routine completion angiography done as a means of quality control.

[Experience of carotid endarterectomy]

The clinical course of 45 patients treated by carotid endarterectomy over the past 5 years is described with emphasis on the following three points: 1) Diagnostic methods, namely digital subtraction angiography (DSA) and B-mode Doppler imaging technique; 2) surgical procedure using an improved shunt tube and surgical instruments; and 3) monitoring before and during surgery. All operations were conducted using a shunt. Morbidity and mortality rates were both 0%. Postoperative transient hemiparesis lasting for 6 hours was recognized in only four cases. The total percentage of correct diagnoses using intravenous DSA compared with conventional angiography was approximately 80%. The accuracy of the non-invasive B-mode Doppler technique in measuring the degree of constriction compared with conventional angiography was 84%. The shunt was made of silicone tubing and was based on a tube 30 cm in length and 3.5 mm in diameter which was a T-shaped loop. Different sized bulbs were fixed to each end of the tube to prevent extravascular deviation. Modified bulldog clamps and Sugita clips were used for fixation in the vessel. Regional cerebral blood flow (rCBF) measurement and electroencephalography (EEG) under contralateral Matas procedure were conducted before surgery, and cross circulation during short-term occlusion of the common carotid artery was evaluated. The emergence or increase of delta waves in EEG during occlusion was observed in six cases. The rCBF of the affected middle cerebral artery territory in these patients was lower than that in patients with no increase of delta waves. Furthermore, the mean stump pressure during surgery in cases with preoperative EEG changes was 40 mmHg and that in cases without changes was 63 mmHg; these values were significantly different.(ABSTRACT TRUNCATED AT 250 WORDS)

Semiclosed transfemoral iliac endarterectomy with an oscillating ring stripper

The technique of endarterectomy for the removal of occlusive atherosclerotic lesions of the aorta and iliac arteries has been utilized successfully in the revascularization of ischemic limbs since its introduction in 1951. The oscillating loop endarterectomy device (Amsco-Hall arterial oscillator) has proven to be useful for endarterectomy of segmental occlusive disease as a substitute for bypass with prosthetic graft. For our elderly debilitated patients, we have adopted a new technique of semiclosed transfemoral iliac endarterectomy for management of occlusive external iliac disease with a patent common iliac artery. We report seven patients treated during May 1987 through May 1988 for external iliac artery occlusion by transfemoral oscillating loop endarterectomy. At 12 months for follow-up review, the cumulative limb salvage rate was 80% with no perioperative mortality. One patient required above-knee amputation eight months following endarterectomy to control forefoot sepsis. Two patients required subsequent leg bypass procedures to achieve full healing of foot level amputation. One patient required dilatation of residual stenosis at the iliac bifurcation by percutaneous balloon angioplasty. Semiclosed transfemoral endarterectomy with the Amsco-Hall oscillating loop device remains an attractive option to the vascular surgeon for recanalization of the iliac artery without the need for an extensive retroperitoneal dissection.

[Coronary atherectomy using a Rotablator]

A system or rotary atherectomy (Rotablator) was evaluated on coronary stenoses in Man. This device consists of catheter presenting an abrasive olive-shaped knob at one end, and sliding over a central metallic guide, rotating at more than 150,000 tpm. This drill liquifies the atheroma in small microparticles able to cross the microcirculation. The atherectomy surface is perfectly smooth and the risk of thrombosis is minimum. The atherectomy technique is quite simple, similar to PTCA, the balloon being replaced by a drill with a diameter ranging from 1.25 to 2 mm. 48 stenoses in 45 patients were treated with this technique. Twice, the Rotablator's guide was unable to cross the stenosis. In other cases, the stenosis was decreased, in an average, by 75 p. cent (SD 24%) to 43 p. cent (SD 20%) (p less than 0.001). The segment treated is characterized by smooth, linear edges without parictal minithrombi. Complications are most unusual (no deaths, no extended infarction, no emergency bypass related an early reobstruction). The coronary artery may react to the passage of the Rotablator by a spasm; this coronary spasm disappears (sometimes in a few hours) under nitrates derivatives perfusion. The middle term results are very encouraging; in fact, in 19 patients who underwent a control coronary angiography 3 months later, 3 (15%) presented a stenosis. In conclusion, rotary angioplasty is an easy, effective and harmless technique. The exact percentage of re-stenosis remains to be specified in larger series.

Closed endarterectomy. Preferred operation for aortoiliac occlusive disease

Closed endarterectomy using the LeVeen plaque cracker was performed on isolated, clamped segments of the unopened aorta, iliac, and femoral arteries. The results of this type of endarterectomy have been analyzed for 111 patients who were followed up from 2 1/2 to nine years. The five-year patency rate was 99%. After nine years, 96.5% of the vessels that underwent surgery remained functionally and radiographically patent. Closed endarterectomy is a substantial improvement over conventional open or half-closed endarterectomy. The closed endarterectomy takes less time, entails little or no blood loss, and is accomplished through a retroperitoneal approach. The aortofemoral bypass graft is inferior to the closed endarterectomy in morbidity, mortality, patency, and alleviation of impotence. Late complications with bypass grafts, using synthetic material, are more numerous and life-threatening.

Selective percutaneous "biopsy" of atheromatous plaque tissue for cell culture

The combination of percutaneous atherectomy and angioscopy enabled a selective "biopsy" of protruding atheromatous plaque material from 11 patients with arterial occlusive disease. The removed specimens were cultivated as adhering explants or single cells were obtained by enzymatic disintegration. The vast majority of the cultivated cells resembled fibroblasts, but could be identified as smooth muscle cells by their smooth muscle alpha-actin content. Proliferation rate was slow with 0.1 doublings per day. Endothelial cells were not observed by immunologic criteria. The described biopsy technique and in vitro evaluation of cultured human atheromatous plaque material may be useful for a better understanding of atherogenesis.

Treatment of symptomatic peripheral atherosclerotic disease with a rotational atherectomy device

Narrowings 70 to 90% in diameter in 3 iliac, 4 superficial femoral and 2 popliteal arteries were crossed and atherectomized successfully in 6 patients using the Squibb Rotablator under angiographic guidance during surgical bypass procedures on these arteries. The Rotablator consists of a 1.25 to 4.5 mm diameter oblong burr with tiny diamond blades mounted on a flexible shaft, which tracks over a spring-tip guidewire and rotates at speeds greater than 120,000 rpm. All stenoses were reduced to less than or equal to 50% of the normal luminal diameter. No significant complications occurred. Of the 6 patients having the atherectomy procedure, 5 were reevaluated by duplex Doppler measurements 1.5 to 5.5 (mean 3.5) months after atherectomy and found to be patient with only mild residual flow disturbance. Repeat follow-up by angiography after a mean of 5.2 months, however, showed only 3 (37%) of the atherectomized segments in 3 patients to still be patent. All were symptomatically improved. Of the effluent particles analyzed, 90% were less than 8 microns in size, while only 5% reached 250 microns. With improvements in technique, the largest particles were 150 to 180 microns, constituting only 1.4% of effluent debris. Samples of the effluent from 2 patients were injected in vivo into the left coronary system of 2 pigs. There were no acute hemodynamic or electrocardiographic complications or pathologic evidence of muscle necrosis or vascular thrombosis 18 to 48 hours later. These preliminary results with respect to feasibility and safety of the Rotablator are promising.

[Endarterectomy using a Simpson catheter in arterial insufficiency of the lower limbs]

Treatment of arterial stenoses by the Simpson atherectomy catheter is carried out by resecting the atheroma. A rotating cutter housed in a cylindrical chamber with a lateral opening is applied against the arterial wall by a low-pressure balloon. Several cuts are made until a large enough diameter of arterial lumen is obtained. We report the results in the first 6 patients treated by this technique using 7F and 9F catheters. All had short (less than 2 cm) and narrow (greater than or equal to 70%) stenoses of iliac, superficial femoral or popliteal arteries. To reduce the stenoses to 30% or less, 4 to 11 cuts were necessary. Histological study of the fragments was performed. The result was inadequate in the only case of stenotic iliac artery and we proceeded with balloon dilatation. The small fragments obtained in this particular case were very hard and calcified. 4 patients with claudication (superficial femoral or popliteal stenosis) were asymptomatic after treatment, whereas one patient suffering from Burger's disease with acral necrotic lesions did not benefit from the procedure in spite of a good morphological result. No complication was encountered. This efficient technique is especially indicated in short segmental stenoses of femoro-popliteal or possibly iliac arteries. It avoids the usual intimal cracks associated with balloon angioplasty and produces a smooth surface whose long term benefit has still to be demonstrated.