Is lower extremity revascularization worthwhile in patients with end-stage renal disease?

BACKGROUND: The purpose of this study was to review the results of lower extremity revascularization in patients with end-stage renal disease and to determine in these patients the functional benefit and cost of an aggressive approach to limb preservation. METHODS: During a 5-year period at our institution, 33 bypass operations were performed on 31 limbs of 23 dialysis-dependent patients. Indications for revascularization were limited (18) or extensive (12) tissue loss or ischemia without tissue loss (3). Procedures included aortobifemoral bypass (1), femoropopliteal bypass (10), and femorotibial/pedal bypass (22). A digital or transmetatarsal amputation was performed in 57% of limbs. RESULTS: The 30-day primary patency was 100%. Cumulative primary and secondary patency rates at 2 years were 65% and 79%, respectively. Limb salvage was 67% and 59% at 1 and 2 years, respectively. Patient survival was poor (47% at 2 years). Peritoneal dialysis was predictive of poor survival (P <.001). Four of 5 patients on peritoneal dialysis died within 3 months of intervention. Extensive tissue loss was predictive of a diminished rate of limb salvage (P =.027). Only 39% of limbs with extensive tissue loss were salvaged at 1 year compared with 78% and 100% of limbs with limited and no tissue loss, respectively. The average hospital cost was $44,308 per year of limb salvage. CONCLUSIONS: Although revascularization of ischemic limbs in dialysis patients can be achieved with an excellent initial graft patency and reasonable limb salvage, patient survival is poor and costs are high. A selective approach to revascularization in these complicated patients may be indicated. For patients treated with peritoneal dialysis and for those with extensive tissue loss, primary amputation may be the preferred approach.

Improving cost efficiency on a vascular surgery service.

BACKGROUND: A vascular task force (VTF) consisting of two vascular surgeons and other key personnel was established to reduce costs and improve efficiency in the management of patients on a vascular surgery service. METHODS: The VTF met monthly beginning in 1994 to study and implement changes in the management of patients with (1) abdominal vascular, (2), carotid endarterectomy (3) distal bypass, and (4) other vascular procedures, including amputations. Length of stay, and fixed and variable costs were assessed for change over time using Pearson correlation coefficients. RESULTS: Improvements in efficiency (length of stay) and decreases in costs (fixed and variable costs) from fiscal year 1993 to fiscal year 1996 were significant for the total group of vascular patients (P

Duplex ultrasound criteria for the identification of carotid stenosis should be laboratory specific.

BACKGROUND AND PURPOSE: Published criteria for the determination of carotid stenosis have been widely applied by vascular laboratories. We compared two vascular laboratories and their duplex ultrasound (DU) machines in terms of their overall diagnostic performance and the optimal criteria to identify patients who have a 70% to 99% stenosis of the internal carotid artery. METHODS: Measurements of stenosis by DU and angiography were compared for 123 carotid arteries (60 arteries, laboratory A; 63 arteries, laboratory B). Receiver operating characteristic (ROC) curves were created, and the areas under the ROC curves and the optimal criteria for determining a 70% to 99% stenosis were compared. Multiple regression analysis was used to measure the effect of laboratory on the relationship between angiographic stenosis and DU velocity parameters. RESULTS: Areas under the ROC curves were similar for both laboratories (0.89 to 0.90, laboratory A; 0.90 to 0.92, laboratory B). However, the optimal criterion for the identification of a 70% to 99% carotid stenosis was different for each laboratory. For most velocity parameters, based on regression analyses, the predicted percent angiographic stenosis for laboratory A was significantly greater than that for laboratory B. In addition, performance differed between the laboratories when established criteria from the literature were applied. CONCLUSIONS: Two vascular laboratories with similar diagnostic accuracy by ROC analysis have markedly different "optimal" DU criteria. For a given angiographic stenosis, velocities in one laboratory were consistently greater than those in the other laboratory. Laboratory-specific criteria rather than published criteria should be used to identify patients with internal carotid artery stenoses.

Mid-term and long-term results with directional atherectomy of vein graft stenoses.

PURPOSE: The purpose of this study was to evaluate the outcomes of our 6-year experience with directional atherectomy used for treatment of stenoses in infrainguinal vein grafts. METHODS: From March 1988 to April 1994, 52 directional atherectomy procedures were undertaken in 42 patients to treat 67 stenoses in 44 vein grafts. Follow-up consisted of periodic physical examinations and graft surveillance; ankle/brachial indexes, pulse volume recordings, and color-flow duplex ultrasonography. Follow-up angiography (n = 18) was performed for recurrent symptoms, reproducible drop in ankle/brachial index of greater than 0.15, a twofold to threefold focal increase in peak systolic velocity, or incidentally during evaluation of the opposite leg. RESULTS: Forty-nine of 52 (94%) procedures were technically successful. In two the residual diameter stenosis was greater than 30%, and in one atherectomy could not be performed. Complications were minor in six (11%) and major in three (6%): two acute graft occlusions and one delayed pseudoaneurysm at the atherectomy site. There were no deaths at 30 days. With a mean follow-up of 21 +/- 18 months, 36 of 44 grafts (82%) remained patent without restenosis; 6 others were patent but considered "failed"--5 (11%) with restenosis, 1 with a pseudoaneurysm; and 2 grafts (5%) occluded. Clinically 33 of 44 extremities (75%) were asymptomatic during follow-up. Claudication improved in five, recurred in three, and was unchanged in one. There was one below-knee amputation. Life-table analysis including all 52 procedures reveals cumulative primary atherectomy patency rates for the 44 grafts of 82%, 78%, and 78%, respectively, at 1, 2, and 3 years after atherectomy, and 86%, 83%, and 83% for the 67 individual stenoses treated. CONCLUSIONS: Directional atherectomy of vein graft stenoses has high technical and clinical success rates, acceptably low morbidity rates, and offers better sustained patency rates than balloon angioplasty. Its long-term patency rate seems to approach that of surgical vein patch angioplasty.

Prospective study of wound complications in continuous infrainguinal incisions after lower limb arterial reconstruction: incidence, risk factors, and cost.

BACKGROUND: Wound complications after lower extremity arterial reconstruction can range from a minor lymphatic leak that causes minimal disability to a severe infection that jeopardizes the limb and life of the affected patient. This study was designed to define more clearly the incidence, severity, and the cost of these complications. METHODS: During a 1-year period the infrainguinal incisions of all patients undergoing lower limb arterial reconstruction were evaluated prospectively. One hundred fifty-six infrainguinal incisions were monitored serially for the presence of infection, hematoma, seroma, serous leak, necrosis, or wound dehiscence. The need for additional treatment or services related to these complications and the cost of these services were determined. RESULTS: Complications occurred in 10% of 77 infrainguinal incisions that were isolated to the groin (groin incisions) e.g., after aortobifemoral bypass, femoral endarterectomy). In only one of these patients was significant cost related to treatment of a complication. Complications occurred in 44% of 79 incisions used for femoral popliteal/tibial and pedal bypasses (distal incisions). In this latter group independent predictors of any complication were age (p=0.02) and obesity (p=0.05); predictors of in-hospital infection were preoperative evidence of venous stasis (p=0.01) and preoperative infection in the same extremity (p=0.08). Fifteen distal wound complications provided additional expense related to reoperation, extended hospitalization or rehospitalization, and rehabilitation or visiting nurse services, with a mean cost per patient undergoing reconstruction of $688. CONCLUSIONS: After lower limb arterial reconstruction, infrainguinal wound complications in isolated groin incisions produce minimal morbidity and cost, whereas complications in incisions after distal bypass are both frequent and associated with significant additional expense.

Carotid endarterectomy in asymptomatic patients--is contrast angiography necessary? A morbidity analysis.

PURPOSE: Findings from the Asymptomatic Carotid Atherosclerosis Study (ACAS) indicate that carotid endarterectomy can be beneficial in symptom-free patients with 60% to 99% carotid artery stenosis. However, patients in ACAS who underwent contrast angiography (CA) before carotid endarterectomy were exposed to an additional 1.2% risk of stroke. METHODS: We used the methods of decision analysis to assess whether the overall 5-year stroke risk in symptom-free patients with suspected carotid artery disease can be reduced by preoperative imaging with magnetic resonance angiography (MRA) or duplex ultrasonography (DU). We compared four strategies for the preoperative evaluation of carotid artery stenosis in symptom-free patients: 1) CA alone, 2) MRA alone, 3) DU alone, and 4) MRA and DU with CA when the results of these tests disagree. Accuracies of MRA and DU were estimated from 81 patients exposed to all three procedures; stroke risks for patients with 60% to 99% carotid artery stenosis were obtained from ACAS. RESULTS: For predicting 60% to 99% carotid stenoses, sensitivity and specificity for noninvasive tests, optimized to reduce morbidity, were as follows: DU (0.96, 0.66), MRA (1.00, 0.76), DU/MRA (1.00, 0.86; 26% would require CA). The 5-year stroke risk of these four strategies in order of decreasing benefit was MRA, 6.17%; MRA/DU, 6.34%; DU, 6.35%; and CA, 7.12%. In sensitivity analyses, noninvasive tests were advantageous even if the stroke rate with CA diminished to 0.4%, or if the sensitivity and specificity of noninvasive tests fell to 70%. CONCLUSION: The preoperative use of noninvasive tests resulted in a lower 5-year stroke risk compared with CA in symptom-free patients with suspected carotid artery stenosis.

Preoperative assessment of the carotid bifurcation. Can magnetic resonance angiography and duplex ultrasonography replace contrast arteriography?

BACKGROUND AND PURPOSE: Noninvasive studies are used with increasing frequency to assess the carotid bifurcation before endarterectomy. Therefore, assessment of their diagnostic accuracies is essential for appropriate patient management. We prospectively evaluate two noninvasive tests, magnetic resonance angiography (MRA) and duplex ultrasonography (DU), as potential replacements for contrast arteriography (CA). METHODS: A blinded comparison of three-dimensional time-of-flight (TOF) MRA, two-dimensional TOF MRA, and DU in 176 arteries was performed. CA was used as the standard of comparison. RESULTS: Three-dimensional TOF MRA had a sensitivity of 94%, a specificity of 85%, and an accuracy of 88% for the identification of 70% to 99% stenosis; two-dimensional TOF MRA had a sensitivity and specificity that were approximately 10% lower than those of three-dimensional TOF MRA. DU resulted in a sensitivity of 94%, a specificity of 83%, and an accuracy of 86%. Combining data from three-dimensional TOF MRA and DU, allowing for CA only for disparate results, yielded a sensitivity of 100%, a specificity of 91%, and an accuracy of 94% among concordant noninvasive tests, with CA required in 16% of arteries. MRA accurately differentiated 17 carotid occlusions from 16 high-grade (90% to 99%) stenoses, whereas with DU two patent arteries were identified as occluded and one occluded artery was identified as patent. CONCLUSIONS: Three-dimensional TOF MRA is the most accurate noninvasive test. Combined use of MRA and DU results in a marked increase in accuracy to a level that obviates the need for CA in a majority of patients.

Perioperative imaging strategies for carotid endarterectomy. An analysis of morbidity and cost-effectiveness in symptomatic patients.

OBJECTIVE: To assess the cost-effectiveness of four diagnostic strategies for the preoperative evaluation of symptomatic patients who are potential candidates for carotid endarterectomy (ie, 70% to 99% stenosis): (1) duplex sonography (DS), (2) magnetic resonance angiography (MRA), (3) contrast angiography (CA), and (4) the combination of DS and MRA supplemented by CA for disparate results. METHODS: Cost-effectiveness analysis based largely on published clinical trial data. Sensitivities and specificities of noninvasive tests were estimated from 81 patients undergoing prospective evaluation with DS, MRA, and CA. OUTCOME MEASURE: Incremental cost per quality-adjusted year of life gained. RESULTS: For a hypothetical cohort of symptomatic patients undergoing evaluation for carotid endarterectomy, the combination of tests resulted in the greatest quality-adjusted life expectancy of the four options considered. After incorporating the costs of testing, surgery, and stroke, we found that neither the MRA nor the CA strategy was cost-effective. The combination of tests was more effective but more costly than DS, resulting in an additional cost of $22,400 per quality-adjusted year of life gained. For centers that do not have adequate MRA, CA resulted in an additional cost of $99,200 per quality-adjusted year of life saved compared with DS. CONCLUSIONS: Our results suggest that for the preoperative detection of a 70% to 99% carotid stenosis, the combination of DS and MRA, supplemented by CA for disparate results, is associated with the lowest long-term morbidity and mortality and has a favorable cost-effectiveness ratio. The combination of tests, or DS alone when MRA is not available, could potentially replace the current practice of using CA alone in the preoperative evaluation of patients with symptomatic carotid stenosis.

Platelet attachment stimulates endothelial cell regeneration after arterial injury.

BACKGROUND: Arterial injury is associated with endothelial disruption and attachment of platelets to an exposed subintimal layer. A variety of factors released by platelets may affect the ability of endothelial cells bordering an injury to regenerate. In this study an organ culture model of arterial injury was used to investigate the relationship between attachment of platelets to a superficial arterial injury and endothelial regeneration. METHODS: A defined superficial endothelial injury was made in whole vessel wall explants of rabbit thoracic aorta. Injured explants were treated with either fresh whole platelets, the supernatant of platelets aggregated by collagen, or basic fibroblast growth factor. Four days after injury and treatment, the average distance of endothelial regeneration was determined. RESULTS: A dramatic increase in the rate of endothelial cell regeneration was observed when injured vessels were exposed to fresh whole platelets (p = 0.003). This increase in regeneration was comparable to that observed with fibroblast growth factor. No increase in the regenerative rate was found after exposure of explants to the supernatant of aggregated platelets (p = 0.69). CONCLUSIONS: Platelets stimulate endothelial regeneration at a rate equal to that observed with the potent endothelial mitogen basic fibroblast growth factor. Because this effect was not demonstrated with the supernatant of aggregated platelets, endothelial regeneration may be dependent on attachment of the platelets to the area of injury.

Retroperitoneal hematoma after cardiac catheterization: prevalence, risk factors, and optimal management.

PURPOSE: Retroperitoneal hematoma is an unusual, but potentially serious, complication after cardiac catheterization. The predisposing factors, typical presentation, and clinical course of this iatrogenic complication are identified, and the role of surgery in its treatment is defined. METHODS: A retrospective review of 9585 femoral artery catheterizations over a 5-year period allowed identification and evaluation of all patients with retroperitoneal hemorrhage. RESULTS: Retroperitoneal hematoma developed in 45 patients (overall prevalence 0.5%), with the highest frequency after coronary artery stenting (3%). In the group of patients who underwent coronary artery stenting, statistically significant predictors of this complication included protocol for sheath removal, female sex, nadir platelet count, and excessive anticoagulation. Signs and symptoms included suprainguinal tenderness and fullness in 100%, severe back and lower quadrant pain in 64%, and femoral neuropathy in 36%. Most patients were treated successfully with transfusion alone. Seven patients (16%) required operation; in four, hypotension unresponsive to volume resuscitation developed early after catheterization; and, in three, a progressive fall in hematocrit level led to surgery 24 to 72 hours after catheterization. CONCLUSIONS: Retroperitoneal hematoma after cardiac catheterization can usually be treated by transfusion alone. A small subset of patients who have development of hypotension unresponsive to volume resuscitation require urgent operation.

Do neck incisions influence nerve deficits after carotid endarterectomy?

OBJECTIVES: To determine whether transverse neck incisions for carotid endarterectomy were associated with a similar or greater incidence of cranial nerve complications when compared with vertical skin incisions, and to assess the patient's perception of the appearance of the incision. DESIGN: Prospective, but not randomized. SETTING: A university-affiliated tertiary care hospital. PATIENTS/INTERVENTIONS: Eighty-five consecutive carotid endarterectomy procedures were evaluated prospectively in 80 patients. Although patients were not randomly assigned, consideration was given to having approximately the same number of patients who had carotid endarterectomy performed through transverse neck incision as through vertical neck incision. Forty-four carotid endarterectomies were performed with a vertical incision and 41 procedures were performed with a transverse incision. MAIN OUTCOME MEASURE: To determine the incidence of cranial nerve dysfunction (primarily nerves VII and XII) after operation. RESULTS: The incidence of palsies of cranial nerves VII and XII in the two groups was similar; there was no statistical significance (the seventh nerve palsy, 32% transverse vs 25% vertical; the 12th nerve palsy, 15% transverse vs 20% vertical). Seventy-two percent of the deficits had disappeared by the 3- to 6-month follow-up. Patients expressed a clear preference for the transverse incision (P = .04). CONCLUSIONS: Although surgical exposure was simpler with the vertical incision, adequate exposure with the transverse incision was always possible. The incidence of mostly temporary deficits of cranial nerves VII and XII was similar. Patients favored the transverse incision.

Neuropathy after cardiac catheterization: incidence, clinical patterns, and long-term outcome.

PURPOSE: Neuropathy is a rare, but potentially morbid, complication of cardiac catheterization. In this study, we report the incidence of this complication and describe its clinical presentation, cause, and natural history. METHODS: Between 1988 and 1993, 9585 cardiac catheterizations were performed at this institution. Patients in whom femoral neuropathy developed were identified through a cardiology registry. Hospital and outpatient records and personal interviews were used to determine the presentation and clinical course of each of these patients. RESULTS: Peripheral neuropathy developed in 20 patients (incidence = 0.21%). Two clinical patterns emerged. In 16 patients, large retroperitoneal hematomas were documented by either computed tomography scanning or by physical examination. These patients were admitted with a lumbar plexopathy involving the femoral, obturator, or lateral femoral cutaneous nerves. Long-term follow-up revealed persistent mild sensory neuropathy in five patients and a mild motor deficit in one. In four patients a groin hematoma or false aneurysm developed which resulted, in paresthesias involving the medial and intermediate cutaneous branches of the femoral nerve. Symptoms completely resolved in all four patients, although false aneurysms were surgically repaired in two. CONCLUSIONS: Neuropathy after cardiac catheterization can be initially disabling, but it is usually completely reversible. Operation is recommended only for coexisting complications.

Accuracy of clinical examination in the evaluation of femoral false aneurysm and arteriovenous fistula.

A prospective study was undertaken to define the comparative value of physical examination versus duplex scanning in the detection of femoral false aneurysm and arteriovenous fistula after percutaneous femoral artery puncture. Fifty-three patients were referred to the vascular surgery service after femoral artery catheterization for evaluation of a groin hematoma or a new femoral bruit. All patients were evaluated initially by a vascular surgeon and then by duplex scan. The results of these evaluations were compared with the findings at operation. Physical examination was 100% sensitive and 100% specific in the diagnosis of arteriovenous fistula, whereas duplex scan achieved a sensitivity of only 58% and a specificity of 100%. Physical examination was 92% sensitive and 93% specific in the detection of femoral false aneurysm compared with a sensitivity of 83% and a specificity of 100% for duplex scanning. Physical examination is the best method for detecting and following patients with arteriovenous fistula. False aneurysms can be detected reliably by physical examination, although evaluation with a duplex scan is necessary to identify the precise size and anatomy of these lesions.

A prospective study of the clinical outcome of femoral pseudoaneurysms and arteriovenous fistulas induced by arterial puncture.

PURPOSE: Although spontaneous thrombosis of femoral false aneurysms (FAs) and arteriovenous fistulas (AVFs) has been reported, the frequency of this occurrence is unknown. This prospective study was designed to establish the natural history of FA and AVF and to evaluate factors that might predict eventual thrombosis of these lesions. METHODS: Twenty-two patients with either femoral FAs (n = 16) or AVFs (n = 6) induced by percutaneous arterial punctures were evaluated prospectively. After an initial duplex scan, all patients were monitored with serial scans, either in hospital or weekly as outpatients, depending on the stability of the process. Operative repair was performed for the following indications: (1) a greater than 100% increase in size of a FA by duplex scan, (2) the development of symptoms, or (3) continued patency of the lesion after 2 months of observation. RESULTS: Nine of 16 FAs and four of six AVFs closed spontaneously; FAs greater than 6 cm3 (1.8 cm in diameter) required repair more often (p = 0.065). However, size was not an absolute predictor of the need for repair because two small aneurysms (1.6 and 0.7 cm3) remained patent, although both patients were discharged safely from the hospital, and two large aneurysms (13.2 and 10.7 cm3) thrombosed spontaneously. Three of seven patients whose aneurysms required repair received anticoagulation continuously from the time of catheterization until repair became necessary. None of the patients whose FAs closed spontaneously were receiving anticoagulants at the time of thrombosis (p = 0.02). Neither length of the FA neck, velocity in the FA cavity, size of original arterial puncture, nor velocity in the AVF correlated with thrombosis. CONCLUSIONS: We conclude that (1) all FAs do not thrombose spontaneously and at least one third require surgical repair, (2) patients receiving continuous anticoagulation should undergo aneurysm repair, (3) discharge of patients with FAs less than 6 cm3 is safe (the majority of these FAs will eventually thrombose spontaneously), and (4) many AVFs close spontaneously and repair is not required unless symptoms or signs of progressive enlargement develop.

Peripheral directional atherectomy: 4-year experience.

Directional atherectomy alone or with supplemental percutaneous transluminal angioplasty was used to treat peripheral vascular lesions in 77 patients (85 procedures). Lesions involved 17 iliac arteries, 45 infrainguinal arteries, and 23 laser extremity vein bypass grafts. Technical success, defined as reduction of stenosis diameter to 30% or less of the normal vessel diameter, was achieved in 78 of 85 (92%) cases. The complication rate was 21% (18 of 85 procedures). Most complications were minor and were related to puncture sites. Patients underwent noninvasive follow-up studies, including measurement of ankle-brachial index and segmental pressures, plethysmography, and clinical examination. The mean follow-up period was 13.5 months. The probability of 1-, 2-, and 3-year patency for lesions treated with atherectomy alone was 92%, 84%, and 84%, respectively. Kaplan-Meier survival analysis revealed no difference in 2- to 3-year patency rate on the basis of lesion location or presence of calcification, eccentricity, or ulceration. Diabetic patients, however, had a higher restenosis rate than did patients who were not diabetic (P less than .03).

Piggy-back mesenteric arterial reconstruction.

Reimplantation of stenotic or occluded visceral arteries into the aorta is one solution to symptomatic chronic visceral ischemia. We report a patient in whom the associated problem of small bowel infarction precluded prosthetic reconstruction and saphenous vein was unavailable. Reimplantation of the celiac artery into the aorta was combined with piggy-back reimplantation of the superior mesenteric artery into the side of the celiac artery to provide successful revascularization of the small bowel. A 16-month angiographic and 5-year clinical follow-up is provided.

Role of superficial femoral artery puncture in the development of pseudoaneurysm and arteriovenous fistula complicating percutaneous transfemoral cardiac catheterization.

Of 13,203 transfemoral diagnostic and therapeutic cardiac catheterization procedures performed between January 1, 1980 and December 31, 1990, 73 (0.55%) were complicated by pseudoaneurysm (PA) formation, and 15 (0.11%) by arteriovenous fistulas (AVF). The rate of PA increased progressively from 0.44% (1980-1987), to 0.59% (1987-1989), to 0.92% (1990), with no corresponding change in the incidence of AVF. The rising incidence of PA complicating transfemoral cardiac catheterization was associated closely with the use of larger diameter catheters and aggressive antiocoagulation during coronary interventions, but findings during surgical repair suggested that puncture of the superficial femoral (SFA), rather than the common femoral artery (CFA), was an important avoidable cause of some PA and AVF. A technique for fluoroscopic localization of the puncture site to avoid inadvertent SFA puncture and the associated increased risk of complication is proposed.