Intraluminal vascular ultrasound: Preliminary report of dimensional and morphologic accuracy

The role of intraluminal ultrasound for diagnosis and monitoring treatment of vascular disease has yet to be defined. This study evaluated the dimensional precision and morphologic accuracy of an intraluminal ultrasound system which consists of a 5.5 French external diameter ultrasonic catheter with a central lumen for passage of a guidewire. Ultrasound images from five in-vitro human and three porcine arterial segments and two in-vivo arteriosclerotic canine arteries were compared to dimensions obtained from arteriograms and from sections of the specimens. Each gross and histological specimen and ultrasound image was scaled, photographed and enlarged up to 20 times and measured for vessel intraluminal and adventitial or outer diameter and wall thickness. Intraluminal and outer diameters and wall thickness from normal in-vitro specimens correlated significantly with dimensions obtained from histologic specimens (r=0.99, p<0.005 for internal and outer diameters and r=0.73, p<0.005 for wall thickness). The mean differences of luminal diameters measured from the vessels supported within a silicone rubber mold was 0.05±0.09 mm (n=20). Diameters of outer diameter and wall thickness were less reliably defined, the average margin of error being 0.49±0.39 mm and 0.29±0.26 mm, respectively. The mean difference between in-vivo ultrasound and arteriographic diameters was 0.61±0.38 mm (n=12). Correlation of luminal diameters between ultrasound and arteriogram was significant (r=0.76, p<0.02). The ultrasound images also differentiated a laminated appearance of normal vessel anatomy from non-uniform or dense signals seen in atherosclerotic lesions. We conclude that the definition of arterial wall morphology and accuracy of dimensions obtained using intraluminal ultrasound compared favorably to those obtained by histology and arteriography. This technology may be valuable for precise intraluminal guidance of angioplasty devices by identifying the location and consistency of atherosclerotic lesions.     

The peripheral vascular consequences of smoking

Cigarette smoking is associated with an increased risk and extent of advanced atherosclerotic vascular disease in peripheral as well as coronary arteries. The likelihood of claudication, amputation, stroke, abdominal aortic aneurysm, and failure of vascular reconstruction is higher in smokers than nonsmokers. Smoking exerts its deleterious effects through many interactive mechanisms. Nicotine and carbon monoxide produce acute cardiovascular consequences, including altered myocardial performance, tachycardia, hypertension, and vasoconstriction. Smoking injures blood vessel walls by damaging endothelial cells, thus increasing permeability to lipids and other blood components. Among metabolic and biochemical changes induced by smoking are elevated plasma, free fatty acids, elevated vasopressin, and a thrombogenic balance of prostacyclin and thromboxane A ₂.Chronic smoking is associated with a tendency for increased serum cholesterol, reduced high density lipoprotein, and other lipid effects that contribute to atherosclerosis. In addition to rheologic and hematologic changes from increased erythrocytes, leukocytes, and fibrinogen, smokers have alterations in platelet aggregation and survival that produce thrombosis. Considering the ubiquitous repercussions of this menace, vascular surgeons should play an active role in motivating their patients to quit smoking.     

Percutaneous transluminal angioplasty of the lower extremities by the vascular surgeon

As vascular surgeons, we performed 376 percutaneous transluminal angioplasties as follows: aorta and iliac arteries (148), infrainguinal arteries (191), and bypass grafts (21). Sixteen procedures were attempted but not completed. Neodymiumyttrium-aluminum-garnet laser thermoprobe was successfully used prior to balloon dilatations in 49 procedures. In contrast to our experience with operative intervention, percutaneous transluminal angioplasty was performed more frequently for claudication (75%), nondiabetics (72%), and women (45%). Median age was 71 years. Percutaneous transluminal angioplasty either preceded or followed proximal or distal open reconstruction in 58 extremities. Primary patency rates for iliac percutaneous transluminal angioplasties were: 94% at one month, 93% at six months, and 88% at one year. For infrainguinal percutaneous transluminal angioplasties they were 95%, 82%, and 70% at 1, 6, and 12 months, respectively. Repeat percutaneous transluminal angioplasty increased the one-year patency rates to 92% and 86% for iliac and infrainguinal percutaneous transluminal angioplasties, respectively. Preliminary data indicate that the six-month secondary patency rates were 82% for laser-assisted percutaneous transluminal angioplasty and 65% for percutaneous transluminal angioplasty of distal bypass grafts. The implementation of balloon angioplasty was facilitated by our 21 years of experience with arteriography. Percutaneous transluminal angioplasty has become a valuable adjunct to the practice of vascular surgery by expanding the therapeutic options for managing peripheral vascular occlusive disease.     

Intraoperative ultrasonography for location of proximal limit of inferior vena caval thrombosis

Appropriate surgical management of inferior vena caval thrombosis is dependent on the proximal limit of the thrombus. Cavograms, computed tomography, or magnetic resonance imaging all have their shortcomings in locating this limit. Intraoperative ultrasonography has allowed us to determine the exact proximal limit of vena caval thrombosis in two patients, one with suprarenal thrombosis, the other with infrarenal thrombosis. In the first patient, caval interruption and clearance of the inferior vena cava was greatly enhanced by the use of this method. Intraoperative sonography is useful in the surgical treatment of thrombosis of the inferior vena cava. (Ann Vasc Surg     

Inhibition of neutrophil superoxide production by adenosine released from vascular endothelial cells

To investigate the inhibitory effect of adenosine released by endothelium on neutrophil Superoxide (O ₂ ^–) production, we treated confluent monolayers of cultured human umbilical vein endothelial cells with the enzyme adenosine deaminase, and then added human neutrophils. Superoxide (O₂ ^–) production by human neutrophils stimulated with 10^–6 M formyl-methionyl-leucyl-phenylalanine was inhibited by 49% in the presence of a confluent monolayer of human umbilical vein endothelial cells (5.1 ± 0.1 versus 2.6 ± 0.3 nmols O₂ ^–/10⁶ neutrophils). Addition of 0.25 U/ml adenosine deaminase to neutrophils plus endothelial cells restored formyl-methionyl-leucyl-phenylalanine-stimulated neutrophil Superoxide production to the level seen with neutrophils alone. Deoxycoformycin (10^–4 M), an inhibitor of adenosine deaminase activity, prevented the increase in Superoxide production associated with adenosine deaminase addition. The adenosine analogue 5-(N-ethylcarboxamido)-adenosine (3 × 10^–4 M) caused increased inhibition of formyl-methionyl-leucylphenylalanine-stimulated superoxide release by neutrophils in the presence of endothelial cells and prevented neutrophil-mediated endothelial cell damage, as measured by release of³H-2-deoxy-D-glucose. Pairing 2-chloroadenosine (10^–5 M) or 5-(N-ethylcarboxamido)-adenosine (3 × 10^–4 M) with a cyclic adenosine monophosphate phosphodiesterase inhibitor, 3-isobutyl-l-methyl-xanthine (10^–4 M), produced greater inhibition of neutrophil superoxide production than occurred with either compound alone. The results support the hypothesis that vascular endothelial cells protect themselves from neutrophil attack by releasing adenosine to inhibit superoxide production.     

Surgical reconstruction of the internal carotid artery with contralateral occlusion without use of shunt

Between 1979 and 1989, 133 carotid artery reconstructions were performed in 130 patients with contralateral internal carotid artery occlusion. These 133 reconstructions represent 7.3% of 1815 revascularizations of the internal carotid artery for atheromatous lesions performed during the same period. There were 113 men (87%) and 17 women (13%) whose mean age was 64.8 years (range 38 to 83 years). Forty-two patients (32%) had coronary artery disease and 77 (59%) were hypertensive. Nineteen patients (14%) were asymptomatic; 16 (12%) had symptoms of isolated vertebrobasilar insufficiency; 19 (14%) had ipsilateral carotid symptoms (on the side of operation); 67 (51%) had contralateral symptoms (on the side of occlusion); and 12 (9%) had bilateral carotid symptoms. All procedures were performed under general anesthesia without the use of a shunt. Nine patients (6.8%) died in the postoperative period (eight of neurologic and one of respiratory causes). Twelve patients (9%) sustained a cerebral vascular accident (eight ipsilateral and four contralateral). Four of these cerebral vascular accidents were diagnosed upon awakening, the remaining eight occurred after an initial uneventful recovery. Combined neurologic mortality and morbidity was 9.8%. Patients with occlusive lesions of the contralateral carotid artery undergoing internal carotid artery reconstruction are at high risk for postoperative cerebral vascular accidents. It is in this group of patients that the various methods of monitoring and cerebral protection should be evaluated.Presented at the Annual Meeting of the Société de Chirurgie Vasculaire de Langue Française, May 18–19, 1990, Nancy, France.     

Angioscopic assessment of fibrinolysis for impending in situ saphenous vein graft thrombosis

A failing femorotibial in situ saphenous vein bypass graft was found by angioscopic examination to be lined with white thrombus and was successfully treated by intraoperative lytic therapy rather than by thrombectomy with a balloon catheter. The platelet-fibrin debris was completely cleared by 250,000 units of urokinase. There were no bleeding complications and the potential for mechanical damage to the venous endothelium was prevented. The in vivo angioscopic observations of fibrinolysis are described.     

111Indium is an unreliable in vivo label for vascular endothelial cells

We studied the retention of ¹¹¹Indium-labeled canine endothelial cells on 32 grafts (16 dogs). Canine endothelial cells were harvested from the external jugular veins, grown in culture, and labeled with¹¹¹Indium oxine; 10⁶ factor VIII positive cells were inoculated on fibronectin-coated, 4 mmlD Hytrel grafts and cultured 18 hours to reach confluence. An autologous seeded graft was interposed in each of the common carotid arteries and exposed to flow for six hours.¹¹¹Indium label was measured pre- and postperfusion and corrected for decay. Twenty-five grafts from 13 dogs were available for study. Scanning electron microscopic planimetry was used to determine percent surface coverage by six mutually exclusive surface characteristics: endothelial cells, bare graft, white blood cells on graft, white blood cellson endothelium, white blood cells under endothelium, and thrombus. ¹¹¹Indium retention was compared with percent coverage by scanning electron microscopy using regression analysis.¹¹¹Indium labeling projected an erroneous retention of 41% at zero percent coverage (r=0.67; p<0.01). Multiple regression analysis revealed an equivalent distribution of¹¹¹Indium label over nonendothelial portions of the flow surface and indicated a leak rate into the circulation of 25.6% of the initial¹¹¹Indium label over six hours. We conclude that: 1)¹¹¹Indium labeling data usually overestimates endothelial cell retention; 2) an average of 4.67%/hour is lost into the general circulation; 3)¹¹¹Indium label can be found equally on surfaces of thrombus, white blood cells, and hydrophilic Hytrel graft; and 4)¹¹¹Indium labeling is not a reliable method forin vivo studies of endothelial cell retention.     

Monobloc resection of the upper extremity of the leg for bone tumor with distal vascular reconstruction

A patient with juxtacortical osteosarcoma of the upper extremity of the left tibia which encased the popliteal neurovascular bundle was treated by monobloc resection of the superior extremity of the tibia and the tibial nerve. The knee joint was replaced by a Guepar prosthetic knee. Arterial and venous continuity was reestablished by a double bypass using the contralateral greater saphenous vein. One year later the patient had good lower limb function and was free of local or general disease. This observation confirms that preservation of lower limb function is possible using reconstruction techniques of bone, nerves, and vessels in sarcoma of the musculoskeletal system.     

Prevention of vascular graft infection by rifampin bonding to a gelatin-sealed dacron graft

This study examines the efficacy of rifampin bonding to a gelatin-sealed knitted Dacron graft to prevent perioperative bacteremic vascular graft infection. Antibiotic bonding was obtained by soaking grafts for 15 minutes in a 1 mg/ml saline solution of rifampin at 37°C. Nineteen dogs had thoracoabdominal aortic bypass: seven (group I) received a rifampin treated graft; six (group II) received an untreated gelatin-coated graft; and six (group III) received an uncoated Dacron graft. Two days later bacteremic challenge was produced by rapid intravenous injection of 5×10 ⁵ colony forming units of methicillin resistantStaphylococcus aureus.Grafts were harvested five days after this challenge and cut into 10 fragments, each submitted to bacterial counts. Results were expressed as CFU/cm ² of graft material. In group I, no graft was infected, whereas all grafts in groups II and III were infected (p<0.05). Median bacterial counts from the infected fragments (median±SD) were similar in groups II (2.5×10⁵ CFU/cm²) and III (4×10⁴ CFU/cm²). Blood cultures at time of sacrifice were negative in all dogs in group I and positive in five of six dogs in groups II and III. Cultures of liver, spleen, kidney, and lung specimens were always negative in group I and positive in 22 of 24 specimens in group II and 23 of 24 specimens in group III. Soaking a gelatin-sealed Dacron graft in rifampin solution evidently prevents early bacteremic graft infection and secondary foci of infection in this model.Presented at the Annual Meeting of the French Vascular Surgery Society, Nancy, France, May 18–19, 1990.     

Mechanisms of ceftriaxone prophylaxis against late bacteremic vascular graft infection caused byStaphylococcus aureus in a dog model

Possible mechanisms of the prophylactic effect of ceftriaxone against late bacteremic vascular graft infection in dogs were investigated. Dogs bearing an expanded polytetrafluoroethylene graft implanted as thoracoabdominal aortic bypass for one month were exposed to transient bacteremia produced by intravenous injection of 2.6±1.8 × 10⁸ colony forming unitsStaphylococcus aureus 209P-R. To assess the effect of the antibiotic on bacteria already adherent onto the grafts, we compared the results from six untreated dogs used as controls and six dogs receiving ceftriaxone (0.5 g, intramuscularly) 90 minutes after the bacteremic challenge. The grafts were removed one week after the bacteremic challenge and cut into 10 to 15 fragments, each submitted to viable bacterial counts. The number of grafts and the number of fragments yielding bacterial growth were the same in the two groups. However, the median density of bacteria was lower (p< 0.01) in the dogs given ceftriaxone, 64 colony forming units/cm (range: 3–8,700), than in the control dogs, 585 colony forming units/cm (range: 12–64,000), suggesting that ceftriaxone had an effect on the postadherence phase of the development of infection. To assess the effect of ceftriaxone on the adherence phase we compared the results from seven untreated dogs and seven dogs receiving ceftriaxone (0.5 g intramuscularly) 90 minutes before the bacteremic challenge. The grafts were removed two hours after the bacteremic challenge. Though all the seven grafts were colonized in each group, the number of fragments yielding bacterial growth was lower (p<0.05) in the dogs given ceftriaxone (59/70) than in the control dogs (90/91). Several mechanisms may be responsible for successful antibiotic prophylaxis of graft infection, involving both early events and postadherence effects. Part of this work was presented at 27th Interscience Conference on Antimicrobial Agents and Chemotherapy, Abstract n 513, October 4–7, 1987, New York, New York.     

The assessment of P-wave dispersion and myocardial repolarization parameters in patients with chronic kidney disease

Objective: The risks of sudden death and cardiac arrhythmia are increased in patients with chronic kidney disease (CKD). Here, we aimed to evaluate the indicators of arrhythmias, such as p-wave dispersion (P-WD), QTc dispersion, Tp-e and Tp-e/QT ratio in patients with CKD stages 3–5 on no renal replacement therapy (RRT).

Material and methods: One-hundred and thirty three patients with CKD stages 3–5 and 32 healthy controls were enrolled into the study. No patients received RRT. QTc dispersion, P-WD and Tp-e interval were measured using electrocardiogram and Tp-e/QT ratio was also calculated.

Results: Mean age rates were found similar in patients and controls (60.8?±?14.2 and 61?±?12.9?y, p?=?.937, respectively). Compared patients with controls, P-WD (45.85?±?12.42 vs. 21.17?±?6.6?msec, p?p?p?p?p?p?=?.001) were found to be different. QTc-max and Tp-e interval were found to be similar in both groups.

Conclusion: P-WD and QTc dispersion, Tp-e interval and Tp-e/QTc ratio were found to be increased in with CKD stages 3–5 on no RRT.     

Transfemoral intraluminal graft implantation for abdominal aortic aneurysms

This study reports on animal experimentation and initial clinical trials exploring the feasibility of exclusion of an abdominal aortic aneurysm by placement of an intraluminal, stent-anchored, Dacron prosthetic graft using retrograde cannulation of the common femoral artery under local or regional anesthesia. Experiments showed that when a balloon-expandable stent was sutured to the partially overlapping ends of a tubular, knitted Dacron graft, friction seals were created which fixed the ends of the graft to the vessel wall. This excludes the aneurysm from circulation and allows normal flow through the graft lumen. Initial treatment in five patients with serious co-morbidities is described. Each patient had an individually tailored balloon diameter and diameter and length of their Dacron graft. Standard stents were used and the diameter of the stent-graft was determined by sonography, computed tomography, and arteriography. In three of them a cephalic stent was used without a distal stent. In two other patients both ends of the Dacron tubular stent were attached to stents using a one-third stent overlap. In these latter two, once the proximal neck of the aneurysm was reached, the sheath was withdrawn and the cephalic balloon inflated with a saline/contrast solution. The catheter was gently removed caudally towards the arterial entry site in the groin to keep tension on the graft, and the second balloon inflated so as to deploy the second stent. Four of the five patients had heparin reversal at the end of the procedure. We are encouraged by this early experience, but believe that further developments and more clinical trials are needed before this technique becomes widely used.     

Intravenous digital subtraction arteriography in the evaluation of vascular grafts

Between 1982 and 1986 intravenous digital subtraction arteriography was used to evaluate vascular grafts in 97 patients (54 males, 43 females). Indications included recurrent symptoms, absent or diminished pulses, a drop in Doppler pressure measurements, and clinical uncertainty with respect to graft patency. Problems identified included graft stenosis, stenosis of the anastomosis or its distal vessels, false aneurysm, arteriovenous fistula and emboli. Forty-eight operations were carried out following intravenous digital subtraction arteriography, and radiographic findings were verified surgically. Twice, intravenous digital subtraction arteriography did not show significant graft findings which were discovered at surgery. Thus intravenous digital subtraction arteriography showed a sensitivity of 95.8% and specificity of 100%. Complications following intravenous digital subtraction arteriography were: two patients developed urticaria, and one superficial thrombophlebitis. There were no cases of pulmonary edema or death. In conclusion intravenous digital subtraction arteriography is very useful in the diagnosis of graft-related problems if done on a selective basis looking at graft and anastomosis site only, intravenous digital subtraction arteriography is done on an outpatient basis, has high sensitivity and specificity, good patient acceptance, is safe, fast and is less expensive than conventional arteriography.     

Pre- and intraoperative transcranial doppler: Prediction and surveillance of tolerance to carotid clamping

We report 91 patients (mean age 70 years) operated upon, prospectively for a total of 100 carotid revascularizations (nine bilateral). Eighty-five of these patients had pre-, intra-, and postoperative transcranial Doppler investigations. Preoperatively, these 85 patients (92 procedures) were classified into two groups based on the results of their Doppler examinations: Group A (65 patients, 72 procedures), those who did not require an intraoperative indwelling shunt and Group B (20 patients, 20 procedures), those who did. The shunt was inserted only when the mean stump (back) pressure was less than 50 mmHg after cross-clamping. Group A all had satisfactory collaterality with a functional anterior and one or two posterior communicating arteries. Group B had no communicating arteries (anterior or posterior) identified by transcranial Doppler. In 17 of 20 patients in this group, the stump pressure was less than 50 mmHg and a shunt was placed. The overall prediction based on Doppler examination of whether or not patients would need a shunt during operation for the two groups A and B (i.e., 92 procedures) was correct in 95.6% (88/92) of cases. Moreover, six hemodynamically significant stenoses (four in the cavernous portion, two in the middle cerebral artery) were disclosed. Sensitivity and specificity of transcranial Doppler as correlated with arteriographic findings were 70 and 90%. Preoperative transcranial Doppler can measure the velocities of the principal cerebral arteries and the collateral capacity of the circle of Willis, and can forecast tolerance to carotid cross-clamping. Intraoperatively, the velocity of flow in the middle carotid artery was correlated with stump pressure, which allowed for surveillance of the shunt.Presented at the Annual Meeting of the Société de Chirurgie Vasculaire de Langue Française, May 18–19, 1990, Nancy, France.     

Long-term results of thrombectomy for late occlusions of aortofemoral bypass

Sixty-two first episodes of aortofemoral (eight patients) or aortobifemoral (42 patients) bypass thrombosis were operated upon in 50 patients between 1980 and 1985. There were 47 men and three women whose mean age was 58 years. Retrograde thrombectomy through the distal anastomosis was achieved in all cases by using either a balloon catheter or Vollmar rings. If thrombectomy was impossible, revascularization was ensured by an extraanatomic bypass or complete replacement of the graft. Angioplasty, repeat distal anastomosis or femoropopliteal bypass of the native runoff artery were done in 55 (89%) operations. The cause of thrombosis was elucidated in 45 cases. Suture line stenosis and atheromatous stenosis of the native runoff artery were the two most common causes. Three patients died and two required above-knee amputation in the immediate postoperative period. Contralateral embolism occurred in two patients undergoing retrograde thrombectomy. Mean follow-up was 47 months. Thrombectomy was possible in 51 of 62 prosthetic thromboses (Group I). Thirty-nine of these grafts have remained patent. Twelve instances of repeat thrombosis occurred, requiring either repeat thrombectomy or a new bypass. Primary patency in group I was 97.8%, 81.2%, and 71.3% at one, three, and five years, respectively. Thrombectomy was impossible in 11 graft thromboses (Group II). A new bypass was performed in all 11 cases. Primary patency in Group II was 100%, 75% and 50% at one, three, and five years, respectively. Retrograde thrombectomy combined with treatment of native runoff artery anomalies can restore long-term patency when thrombosis occurs late after aortofemoral bypass and is associated with low mortality and morbidity.Presented at the Annual Meeting of the Société de Chirurgie Vasculaire de Langue Française, May 18–19, 1990, Nancy, France.     

Spontaneous dissecting aneurysm of the common iliac artery

A 52-year-old man sought medical advice for sudden onset of intermittent claudication of the left lower limb after 50 meters walking. Aortography documented a dissecting aneurysm limited to the left common iliac artery. After resection, a prosthetic graft was inserted. Pathology showed that the cause of the dissection was atheroma. Spontaneous dissecting aneurysm of the common iliac artery is rare. Rupture represents the principal hazard. A high index of suspicion should lead to diagnosis as soon as signs of lower limb ischemia, occasionally transient, appear.     

Acute arterial insufficiency of the male genitalia

Three patients developed severe ischemia of the penis or scrotum from acute arterial occlusion. In one case, nonhealing ulceration of the glans developed after atheroembolism to the dorsal penile artery. One patient had penile ischemia after ligation of pelvic and femoral collateral circulation during repair of an aorto-bilateral-iliac artery aneurysm. A third patient had ischemia of the penis and scrotum from thromboembolism to the iliac arteries during repair of an aortoenteric fistula. Only seven patients have been described with acute arterial occlusion and severe ischemia of the male genitalia. A rare phenomenon because of rich collateral circulation, acute ischemia of the genitalia nevertheless must be recognized as a sign of severe vascular disease and a consequence of major arterial ligation or occlusion in the pelvis and groins.     

Hyperparathyroidism presenting as an unusual cause of lower extremity gangrene

Vascular surgeons are often consulted on the management of lower extremity ulcerations and gangrene which are commonly due to atherosclerotic arterial occlusive disease or to chronic venous insufficiency. The following report describes an unusual case of severe lower extremity cutaneous gangrene associated with secondary hyperparathyroidism and a review of the literature.     

Pentoxifylline in the nonoperative management of intermittent claudication

To assess the clinical effectiveness of pentoxifylline (Trental) in the treatment of intermittent claudication and ischemic rest pain, 129 patients were retrospectively interviewed with respect to compliance and improvement of symptoms. Risk factors for the development of atherosclerosis were tabulated, as was the severity of symptomatic lower extremity peripheral vascular insufficiency. The duration of pentoxifylline treatment was 35.8±45.0 weeks (mean±1 S.D.). Forty-eight percent of the patients discontinued pentoxifylline on their own, most commonly because of side effects (13%) or perceived lack of improvement (23%). Of those patients taking pentoxifylline for eight weeks or more (n=110), 64% noted some improvement, with 31% reporting increased claudication distance and 52% reduced claudication pain. Pentoxifylline provided pain relief in 52% of patients with ischemic rest pain (n=27). Neither diabetes, hypertension, concomitant antiplatelet therapy, the severity of claudication, nor pretreatment ankle-brachial Doppler pressures were related to treatment outcome. Increased daily walking exercise during treatment was associated with successful outcome (p=0.04). Clinical response to pentoxifylline was inversely related to the number of cigarettes smoked daily in those with 1 block claudication (n=71, p=0.05). Pentoxifylline was not very effective in increasing reported claudication distance. This review suggests that pentoxifylline may be of value for patients with ischemic rest pain when arterial reconstruction is not possible. Whether pentoxifylline is useful adjunctive therapy for intermittent claudication requires further scrutiny.