Enrique Criado

The role of air plethysmography in the diagnosis of chronic venous insufficiency

PURPOSEnThe role of air plethysmography (APG) in the diagnosis of venous disease is not well defined. We conducted this study to investigate the value of APG in the diagnosis of chronic venous insufficiency and to determine its correlation with the clinical severity of disease and the anatomic distribution of reflux.nnnMETHODSnWe studied 186 lower extremities with duplex scanning and venography and measured the venous volume, venous filling index (VFI), ejection fraction, and residual volume fraction with APG. Limbs were categorized according to the Society for Vascular Surgery and International Society for Cardiovascular Surgery classification of clinical severity of disease and according to the anatomic distribution of valvular incompetence.nnnRESULTSnSixty-one limbs had no evidence of disease (class 0), 60 limbs had mild disease (classes 1, 2, and 3), and 65 limbs had severe disease (classes 4, 5, and 6). According to the results of duplex scanning and venography, there was no evidence of reflux in 56 limbs. Isolated superficial venous reflux occurred in 52 limbs, and perforator reflux, alone or in conjunction with superficial reflux, occurred in 30. Deep reflux, with or without superficial reflux, was found in 25 limbs. Deep and perforator reflux, with or without superficial reflux, was found in 19 limbs. The VFI had a sensitivity of 80% and 99% positive predictive value for any type of reflux. The VFI was significantly different between groups of limbs with different clinical severities of disease or different types of reflux. The incidence of deep or perforator reflux in limbs with a normal VFI value was 7%, and it was 82% in limbs with a VFI of more than 5. Among 86 limbs with VFI values not corrected with use of a thigh tourniquet, 28% did not have evidence of deep or perforator reflux, and among 15 limbs with VFI values corrected with the use of a tourniquet, 33% had perforator reflux, deep reflux, or both. All APG parameters had low positive predictive values for severe disease or ulceration. The ejection fraction and residual volume fraction did not influence the clinical severity of disease, did not discriminate between types of reflux, and in combination with the VFI did not improve the predictive value of APG.nnnCONCLUSIONSnThe VFI measured by APG is an excellent predictor of venous reflux, provides an estimate of the clinical severity of disease, and at high levels predicts deep reflux, perforator reflux, or both. Correction of an abnormal VFI with a thigh tourniquet is an unreliable predictor of the absence of deep or perforator incompetence. The predictive value of APG for severe disease or ulceration is poor. The ejection fraction and residual volume fraction, individually or in combination with the VFI, add little to the diagnostic value of APG, and their routine performance may not be clinically justified.

Femorofemoral bypass grafts: Analysis of patency and factors influencing long-term outcome

Abstract Purpose: xa0To evaluate the results of femorofemoral bypass graft (FFBPG), we analyzed 110 consecutive FFBPGs performed at our institution during an 11-year period. Methods: xa0In 62 (56%) patients the indication for surgery was claudication and in 48 (44%) patients rest pain or tissue loss. In 42 patients the superficial femoral artery (SFA) was occluded. A preoperative percutaneous transluminal balloon angioplasty (PTA) was performed in 24 (22%) patients to correct a significant donor iliac artery stenosis. In 48 (44%) patients a total of 54 arterial procedures were performed simultaneously with FFBPG. Results: xa0After surgery 75 (68%) patients were moderately or markedly improved, whereas 20 (18%) were minimally improved, unchanged, or worse, including 7 (6%) with hemodynamic failures. The in-hospital mortality rate was 4.5%. Actuarial patient survival rate was 70% ± 8.6% at 6 years. The actuarial primary graft patency rate was 83% ± 4.2% at 1 year, 71% ± 6.9% at 3 years, 60% ± 8.3% at 5 years, and 51% ± 9.6% at 6 years. Age, sex, and race of the patient did not influence graft patency. Grafts placed for limb-threatening ischemia or in patients with SFA occlusion had a similar patency rate compared with those placed for claudication or in patients with patent SFA. The overall limb preservation rate was 83% ± 7.3% at 5 years but was only 64% for patients who underwent operation for limb-threatening ischemia. Conclusions: xa0In conclusion, FFBPG offers moderately low long-term patency in a population with limited survival. Outflow procedures performed concomitantly with FFBPG seemed to compensate for the negative impact on graft patency rate of ipsilateral SFA occlusion and limb-threatening ischemia. Limb-threatening ischemia, however, carried a significantly higher ( p

Proximal venous outflow obstruction in patients with upper extremity arteriovenous dialysis access

To evaluate the impact of central venous obstruction on upper extremity hemodialysis access failure, we retrospectively analyzed our recent experience in managing this problem. We reviewed 158 upper extremity hemodialysis access procedures performed in 122 patients during a 1-year period. Fourteen (11.5%) patients had central vein obstruction as the cause of severe arm swelling, graft thrombosis, or graft malfunction. All 14 patients had had bilateral temporary subclavian vein dialysis catheters and failed upper extremity arteriovenous access. Seventeen lesions were treated in 14 patients including eight subclavian vein occlusions, six subclavian vein stenoses, two internal jugular vein stenoses, and one superior vena cava stenosis. Twenty-one procedures were performed including 17 percutaneous transluminal balloon angioplasties (PTAs) with stent placement in 13, two axillary to innominate vein bypasses, and two axillary to internal jugular vein bypasses. All patients had resolution of symptoms. Thirteen (76%) PTAs were initially successful but in four (24%) cases it was impossible to recanalize the vein. Eight (47%) PTAs provided functional hemodialysis access for 2 to 9 months, two (12%) restenosed at 3 and 10 months and were successfully redilated, two occluded at 2 and 4 months and were unable to be recanalized, and one failed immediately after a successful PTA. Four PTA failures were followed by venous bypass, which remained patent and provided functional access 7 to 13 months after surgery. Of nine stenotic venous lesions six (67%) were successfully dilated without restenosis, whereas of eight occluded veins only two (25%) were successfully treated without recurrence. Temporary central hemodialysis catheters produce a significant number of symptomatic central vein obstructions in patients with upper extremity arteriovenous access. PTA with stenting and venous bypass provides early success in most patients. Transcatheter therapy is less successful in treating complete venous occlusions when compared with stenotic lesions. All effort should focus on preventing this complication by avoiding the use of temporary subclavian vein hemodialysis catheters.

An aortic aneurysm model for the evaluation of endovascular exclusion prostheses

PURPOSEnThe purpose of this study was to develop an aortic aneurysm (AA) model with a predictable tendency for rupture for the evaluation of the efficacy of endovascular prostheses in preventing rupture and their long-term outcome after implantation.nnnMETHODSnAn infrarenal AA measuring two to three times the diameter of the proximal aorta was created in 18 dogs with a full-thickness patch of jejunum. Seven dogs were allowed to survive without aneurysm exclusion. In 11 dogs the aneurysm was immediately excluded with a stented 8 mm Dacron graft mounted in a 14F delivery system introduced through the femoral artery with aortographic guidance. The pressure differential between the aorta and the excluded aneurysm was measured, and angiography, necropsy, and histologic examination were performed at 3- and 6-month survival.nnnRESULTSnAll animals survived aneurysm implantation. Without aneurysm exclusion, six dogs died of rupture within 1 to 6 days of surgery. In three dogs the exclusion failed because of graft-to-aorta size mismatch or misplacement demonstrated on angiography and by a low pressure differential between the aorta and the aneurysm (< 5 mm Hg); all three dogs died of rupture within 4 days. In eight dogs the aneurysm was successfully excluded on the basis of angiography results, with a mean aorta-to-aneurysm pressure differential of 51 mm Hg. Two dogs were killed at 1 and 6 days after surgery because of paraplegia produced by graft thrombosis because of kinking but without evidence of aneurysm rupture. Six dogs survived on a long-term basis, and angiography and necropsy performed at 3 and 6 months revealed patent grafts without migration, reduction in aneurysm size, no flow in the excluded lumbar arteries in five of six animals, and complete incorporation of Dacron graft and stents. No evidence of graft infection was found in any animal. The survival rate was significantly better (p < 0.023) in dogs with successfully excluded aneurysms (n = 6) compared with that in dogs without exclusion or with failed aneurysm exclusion (n = 7).nnnCONCLUSIONnThis aneurysm model demonstrates that without effective aneurysm exclusion all animals die of rupture and that successfully placed endovascular prostheses can prevent AA rupture with long-term graft patency and stability. Endovascular aortic Dacron grafts in dogs undergo complete incorporation at 3 months from implantation. This aneurysm model is useful for the evaluation of endovascular devices designed for the treatment of AAs.

Transbrachial endovascular exclusion of an axillary artery pseudoaneurysm with PTFE-covered stents.

PURPOSEnEndovascular exclusion of arterial injuries associated with arteriovenous fistulas and pseudoaneurysms has only recently been described using various stent-graft prostheses. This report details a transbrachial technique used to exclude an axillary artery pseudoaneurysm developing at the axillary anastomosis of an axillofemoral graft.nnnMETHODS AND RESULTSnThin-walled polytetrafluoroethylene was expanded with an angioplasty balloon catheter and used to cover standard Palmaz stents. Two covered stents were delivered under fluoroscopic guidance via open brachial artery access to the site, resulting in complete exclusion of the pseudoaneurysm. Follow-up duplex scanning confirmed aneurysm exclusion 3 months postprocedure.nnnCONCLUSIONSnThis technique can be applied in arteries of different sizes and lengths, using currently available materials. However, the long-term behavior of these devices in the arterial tree must be determined before their widespread use can be recommended for most indications.

Descending thoracic aorta-to-iliofemoral artery bypass as an alternative to aortoiliac reconstruction

During the last 3 decades subcutaneous extraanatomic bypass, despite its limited durability, has been the favored alternative to infrarenal aortofemoral bypass. Meanwhile, the descending thoracic aorta has been scarcely used as an inflow source for aortoiliac reconstruction. Over the past 8 years we performed 16 bypasses from the descending thoracic aorta to the iliofemoral vessels for occlusive disease. Our experience combined with that found in the English-language literature totaled 141 patients. In 79 patients (56%) the indication for surgery was failure or infection of an abdominal aortofemoral graft. Previous abdominal operations, sepsis, radiation therapy, the presence of abdominal stomas, or an unsuitable infrarenal aorta were the indications in the remaining cases. The combined operative mortality rate was 6.4%. The life-table primary graft patency was 98% at 1 year, 88% at 2 years, and 70.4% at 5 years. Bypass from the descending thoracic aorta to the iliofemoral artery uses an inflow source superior to other extraanatomic reconstructions, does not require aortic cross-clamping, avoids the abdominal cavity, and places the graft remote to the skin and intestine. The operative mortality and patency rates compare favorably to those of other extraanatomic or remedial aortic reconstructions. Descending thoracic aorta to iliofemoral artery bypass is a superb alternative to abdominal aortofemoral bypass, carries a low mortality rate, has an excellent short-term patency, and features unique characteristics for long-term durability.

Management and outcome of chronic atherosclerotic infrarenal aortic occlusion

PURPOSEnTo evaluate the management and outcome of chronic atherosclerotic infrarenal aortic occlusion (IRAO), a review of 48 patients who were treated for angiographically documented IRAO between January 1980 and December 1994 was undertaken. Mean follow-up was 45 months. Mean age was 57 years (range, 33 to 88 years). Forty-seven patients were heavy smokers. Symptoms included claudication in 81%, rest pain in 25%, and tissue loss in 15%. Impotence was documented in 73% of men. Associated arterial disease included inferior mesenteric artery occlusion in 31 patients, renal artery stenosis or occlusion in 12, superior mesenteric artery stenosis in two, and celiac artery stenosis in one.nnnMETHODSnForty inflow procedures were performed, including 17 thoracobifemoral bypass (TBF) procedures, 15 aortobifemoral/iliac bypass (ABFI) procedures, and eight axillobifemoral bypass (AXBF) procedures. Eight patients were managed without surgery. The thoracic aorta was chosen as the inflow source in 17 patients because of previous abdominal aortic surgery in eight, poor status of the abdominal aorta in eight, and horseshoe kidney in one.nnnRESULTSnThe overall operative mortality rate was 5%, and the perioperative morbidity rate was 18%. There was no statistical difference in perioperative mortality and morbidity rates among the operative groups. The five-year survival rate (life-table) for all IRAO patients was 67%. TBF and ABFI revascularization procedures yielded 5-year patency rates of 71% and 79%, respectively (p < 0.05). All eight patients who underwent AXBF died or had occluded grafts at 3 years after surgery. Two-year patency rates (life-table) for TBF, ABFI, and AXBF were 92%, 92%, and 44%, respectively. The AXBF patency rate was significantly inferior to those of TBF and ABFI (p < 0.05). Changes in ankle-brachial indexes after TBF or ABFI were similar, but were significantly greater than changes after AXBF (p < 0.05). Three patients in the nonoperative group died, and two underwent major amputation. Acute renal failure did not occur in our study population. Follow-up creatinine levels > 2.0 mg/dl were documented in three operative patients and in one nonoperative patient, and none required dialysis.nnnCONCLUSIONSnIn patients who have IRAO, aorta-based inflow procedures are superior to AXBF both in hemodynamic outcome and in patency rates. Treatment of IRAO with TBF or ABFI yields similar long-term results; the descending thoracic aorta represents an excellent inflow alternative to the abdominal aorta. Clinically significant renal impairment is rarely associated with IRAO. Nonoperative management of IRAO is associated with an increased mortality rate and a high rate of limb loss.

Results of the ROADSTER multicenter trial of transcarotid stenting with dynamic flow reversal

OBJECTIVEnThis report presents the 30-day results of the Safety and Efficacy Study for Reverse Flow Used During Carotid Artery Stenting Procedure (ROADSTER) multicenter trial and evaluates the safety and efficacy of ENROUTE Transcarotid NPS (Silk Road Medical Inc, Sunnyvale, Calif), a novel transcarotid neuroprotection system that provides direct surgical common carotid access and cerebral embolic protection via high-rate flow reversal during carotid artery stenting (CAS).nnnMETHODSnA prospective, single-arm, multicenter clinical trial was performed to evaluate the use of the ENROUTE Transcarotid NPS during CAS procedures performed in patients considered to be at high risk for complications from carotid endarterectomy. Symptomatic patients with ≥50% stenosis and asymptomatic patients with ≥70% stenosis were eligible to be treated with any U.S. Food and Drug Administration-approved carotid artery stent. The primary end point was the composite of all stroke, myocardial infarction (MI), and death at 30xa0days postprocedure as defined in the Food and Drug Administration-approved study protocol. Secondary end points included cranialxa0nerve injury; 30-day stroke, death, stroke/death, and MI; acute device, technical, and procedural success; and access site complications. All major adverse events were adjudicated by an independent clinical events committee.nnnRESULTSnBetween November 2012 and July 2014, 208 patients were enrolled at 18 sites. Sixty-seven patients were enrolled as lead-in cases, and 141 were enrolled in the pivotal phase. In the pivotal cohort, 26% were symptomatic and 75% were asymptomatic. Acute device and technical success were 99% (140 of 141). By hierarchical analysis, the all-stroke rate in the pivotal group was 1.4% (2 of 141), stroke and death was 2.8% (4 of 141), and stroke, death and MI was 3.5% (5 of 141). One patient (0.7%) experienced postoperative hoarseness from potential Xth cranial nerve injury, which completely resolved at the 6-month follow-up visit.nnnCONCLUSIONSnThe results of the ROADSTER trial demonstrate that the use of the ENROUTE Transcarotid NPS is safe and effective at preventing stroke during CAS. The overall stroke rate of 1.4% is the lowest reported to date for any prospective, multicenter clinical trial of CAS.

Predictive value of clinical criteria for the diagnosis of deep vein thrombosis

BACKGROUNDnThe widespread use of ultrasonography for the diagnosis of deep vein thrombosis (DVT) has led to the overuse of ultrasonography with low diagnostic yield. We conducted this study to investigate the predictive value of clinical features in the diagnosis of DVT and their potential value as clinical guidelines for the use of ultrasonographic testing in the diagnosis of DVT.nnnMETHODSnThe results of lower-extremity duplex ultrasonographic studies and clinical surveys prospectively obtained in 1526 patients suspected of having DVT were analyzed.nnnRESULTSnThere were 916 inpatients and 610 outpatients. Acute DVT was found in 16% of the inpatient duplex scans, and in 12% of the outpatient studies (p < 0.05). The incidence of acute DVT was not different between men and women in inpatient or outpatient populations. Acute DVT was found in the left leg in 60% of the outpatient studies, significantly more often (p < 0.001) than in the inpatients (35%). Bilateral DVT was more common (p < 0.05) in the inpatient population (35%) compared with the outpatient population (20%). No difference in the anatomic distribution of thrombosis was found between inpatients and outpatients. The presence of leg symptoms was associated with a significantly higher rate (p < 0.05) of positive studies compared with those patients without leg symptoms in both the inpatient and the outpatient populations. Individual symptoms, risk factors, and physical findings had low positive predictive value and sensitivity for the presence of acute DVT on duplex scan. A calf circumference discrepancy of less than 2 cm predicted the absence of DVT in 93% of inpatients and 85% of outpatients. The combination of a calf circumference discrepancy of less than 2 cm with the absence of recent operation, trauma, malignancy, previous history of DVT, or hypercoagulable state predicted the absence of DVT in 92% of the inpatients and 97% of the outpatients.nnnCONCLUSIONSnClinical symptoms, risk factors, and physical findings are poor predictors of the presence of acute DVT on duplex scan. However, the absence of a combination of objective clinical factors has high predictive value for the absence of acute DVT on duplex scan. These criteria may be used to establish clinical guidelines to reduce the use of duplex scanning for the diagnosis of DVT.

Trachea-innominate artery fistula: retrospective comparison of treatment methods.

A fistula between the trachea and the innominate artery, a potentially fatal complication of tracheostomy, can be managed successfully. We have derived several guidelines from our experience with one such case and from a review of the 36 cases reported in the literature over the last decade. Diagnosis must be established before exsanguination occurs. Bronchoscopy and angiography are often nondiagnostic. Control of hemorrhage and a patent airway are the initial goals of treatment. Interruption of the innominate artery is the definitive treatment, with a low rebleeding rate (7%, 1/14 cases) and good long-term survival (64%, 9/14 cases). Maintenance of continuity of the innominate artery is contraindicated, because of a high rebleeding rate (60%, 6/10 cases) and poor long-term survival (10%, 1/10 cases). There is no convincing evidence that interruption of the innominate artery causes significant neurologic or vascular compromise.