Faculty Bibliography

BACKGROUND: To examine the effect of office-based duplex-guided balloon-assisted maturation (DG-BAM) on arteriovenous fistula (AVF), we retrospectively analyzed our experience. METHODS: Over the past 10 months, we performed 185 DG-BAMs (range, 1-8 procedures; mean, 3.7) in 45 patients (29 male, 16 female; mean age, 68.2 +/- 12.8 years) with 31 radial-cephalic, 7 brachial-cephalic, and 7 brachial-basilic AVFs. Balloon sizes (3-10 mm) were chosen based on duplex measurements (1-2 mm larger than minimal vein diameter). Forearm AVFs were dilated to 8 mm, and arm AVFs were dilated to 10 mm. RESULTS: All cases but one (99.5%) were successfully dilated. This exception was a large AVF rupture that required surgical repair. AVFs failed to mature in seven of the remaining 44 patients (16%) despite DG-BAM because of proximal vein stenoses (PVS). Four patients had cephalic arch stenoses, and three had proximal subclavian vein stenoses. Arm AVFs were more commonly associated with PVS (6 of 14 patients, 43%) as compared with the ones placed in the forearm (1 of 30 patients, 3.3%), with a P value of 0.0024. All these seven AVFs subsequently matured after successful balloon angioplasty of the venous outflow. CONCLUSIONS: These data suggest that office-based DG-BAM of AVFs is feasible, safe, and averts nephrotoxic contrast and radiation. PVS appear to be the most common cause of failure for AVFs subjected to BAM. Because arm AVFs are at increased risk of PVS, we suggest that a careful duplex evaluation of the outflow be performed in these cases and in all AVFs that fail to mature.

BACKGROUND: To identify patients with pulmonary embolism (PE) without deep venous thrombosis (DVT), and to compare them with those with an identifiable source on upper (UED) and lower-extremity venous duplex scans (LED). METHODS: We performed a retrospective review of 2700 computed tomography angiograms of the chest between January 2008 and September 2010 and identified 230 patients with PE. We then evaluated the results of UED and LED and divided the patients into four groups based on the results of their duplex studies. We compared patients with PE and DVT with those with PE and no DVT in terms of age, gender, size and location of PE, critical illness, malignancy, and in-hospital mortality. RESULTS: We identified 152 women and 78 men (mean age, 68 years) with PE. One hundred thirty-one patients had a documented source of PE (group 1). Fifty-three patients had negative LED results, but did not undergo UED (group 2). Thirty-one patients did not undergo either LED or UED (group 3). Seven men and eight women had no documented source of PE on UED and LED (group 4). Ten of 15 patients in group 4 had a documented malignancy listed as one of their diagnoses. Because patients in groups 2 and 3 did not undergo complete duplex studies, we excluded them from our analysis. We then reviewed the discharge summaries of patients in groups 1 and 4. There was no statistically significant difference in age and gender distribution, size and location of PE, critical illness, smoking status, cardiovascular disease, trauma, and in-hospital mortality between patients in group 1 and 4. Patients in group 4 had a statistically significant increased prevalence of malignancy (67% vs. 40%, P = 0.046). Patients in group 4 also had a higher percentage of active cancer than those in group 1 (47% vs. 24%, P = 0.084), although not statistically significant. We defined active cancer as either a metastatic disease or a malignancy diagnosed shortly before or after the diagnosis of PE. Patients who were undergoing treatment for cancer at the time of diagnosis of PE were also considered to have active cancer. CONCLUSION: We demonstrated a statistically significant increased prevalence of malignancy in patients with PE without DVT. However, pathophysiology and clinical significance are the aspects that remain to be understood after accrual of more patients and further research. Possibilities such as de novo thrombosis of pulmonary arteries, complete dislodgement of thrombi from peripheral veins, or false-negative venous duplex need to be explored.

In this study, we noted the common risk factors with atherosclerosis and chronic renal disease. We, therefore, hypothesized that the placement of a dialysis catheter would be a useful marker in identifying populations at increased risk of vascular disease (carotid, renal, and aortic). To further explore this issue, we examined the results of duplex scanning of the carotid arteries and aortorenal arteries in patients undergoing dialysis catheter placement. Over 49 months, each of the 123 patients who underwent permanent tunneled dialysis catheter placement received a carotid duplex study. Twelve patients (9.8%) had >/= 60% stenosis and 8 patients (6.5%) had 70% to 99% stenosis. Furthermore, 109 patients who underwent a aortorenal artery duplex study were also analyzed. The study population demonstrated a prevalence rate of 3.7% for abdominal aorta aneurysm (AAA) and 4.6% for renal artery stenosis (RAS). Based upon these data, we suggest performing routine carotid duplex scans in patients who will also receive dialysis catheter placement. However, the data did not support routine screening of AAA or RAS.

BACKGROUND: Radiofrequency ablation (RFA) is a widely accepted alternative to high ligation with proximal stripping of the great saphenous vein (GSV) in the treatment of lower extremity venous insufficiency. This study compared short-term outcomes of two generations of (VNUS Closure) RFA catheters, ClosurePlus (CP) and ClosureFast (CF). METHODS: From February 2005 to April 2009, a total of 667 consecutive office-based RFA procedures were performed in our institution. CP catheters were used in the initial 312 lower extremity cases and CF catheters in the 355 cases that followed. The technique used for both catheters were as per the manufacturer's recommendations. Postoperative duplex scans were completed to document the following endpoints: GSV obliteration; incidence of deep venous thrombosis (DVT); superficial venous thrombosis (SVT); and presence of loose or floating thrombus proximal to the treated GSV segment. RESULTS: Of the 667 cases, 98% had available duplex scan studies within 1 week from completion of the procedure. Complete obliteration of the GSV on duplex scan studies was noted in 98% of 343 cases using the CF catheter and 88% of 312 cases using the CP catheter (P < .001). No case of DVT was detected in those treated with the CF catheter, whereas DVT occurred in 3.5% of cases treated with the CP catheter (P < .001). Incidence of SVT was 10% and 15%, respectively, for CF and CP (P < .08). Loose thrombus proximal to the GSV was identified in 7% of cases using CF and 6% of cases using CP (P = .80). No embolic episodes were observed clinically. CONCLUSIONS: CF catheters are superior to CP catheters in terms of GSV obliteration and nonincidence of postoperative DVT. The absence of DVT may likely be due to the commencement of ablation at 2 cm from the GSV-common femoral vein junction.

BACKGROUND: Venous outflow obstruction may play a role in patients with chronic venous stasis symptoms who fail to improve despite conventional modalities of treatment that focus on the reflux component of the disease with little attention to the possibility of an obstructive component. The introduction of minimally invasive venous stenting using venography and intravenous ultrasonography (IVUS) provides the ability to treat the "obstructive" component of the disease. METHODS: We undertook a retrospective review of 56 limbs in 53 patients with chronic venous stasis symptoms. Initial transcutaneous Doppler ultrasonographic evaluation of the inferior vena cava, iliac, femoral, greater saphenous, and perforator veins was performed looking for any evidence of deep venous thrombosis, superficial venous thrombosis, perforator veins, and reflux (location and degree). Afterword, the patients were managed in the conventional fashion (leg elevation, compression, and great saphenous vein (GSV) and perforator ablation, if present) for a period of 3 months. If ulcer healing was not noted, iliac-femoral venography and IVUS were undertaken. A significant stenosis was defined as a 50% reduction in vein cross-sectional area as measured by IVUS.(1,2,3) Stenotic lesions were managed with stenting followed by balloon angioplasty. Patients were followed up for ulcer healing or improvement of stasis symptoms. RESULTS: Of the 56 limbs, 10 (17.8%) had postthrombotic changes, 7 (12.5%) had incompetent perforators, and 27 (48.2%) had an incompetent superficial venous system. In the stented group (n = 29), 3 limbs had perforator ablation alone, 13 limbs had GSV ablation alone, and 1 limb had both perforator and GSV ablation. In the unstented group (n = 27), 10 limbs had GSV ablation alone, and 3 limbs had both perforator and GSV ablation. The overall incidence of deep reflux was 51.8%; 17 of 29 limbs (58.6%) in the stented group had evidence of deep reflux, and 12 of 27 limbs (44.4%) in the unstented group had deep reflux. All venograms except one (98.2%) were performed under local anesthesia with sedation. The procedure was performed in an ambulatory setting in 69.6% (39 of 56) of the limbs. CEAP clinical severity class distribution was as follows: C2, 4%; C3, 16%; C4, 18%; C5, 5%; C6, 57%. Over half of the limbs (29 of 56) were found to have stenotic lesions and required stenting. Eight patients (11 limbs) did not return for ulcer healing assessment. The majority (19 of 29) of limbs in the stented group had a CEAP of 6. Among the patients with CEAP 6 who returned for follow-up (n = 26), 7 had no evidence of stenosis and required no stenting. Only one of those (14.3%) healed his ulcers after 3 months (average follow-up of 4.8 months). The remainder 19 limbs were found to have stenotic lesions and underwent stenting. The ulcers healed in 11 of those (58%) over a period of 1 week to 8 months (average of 5 months), with average follow-up of 3.6 months (p = 0.08). The cumulative primary and secondary patency rates were 93.1% (27 of 29) and 100% (29 of 29), respectively. Two stent thromboses occurred within 4 weeks of the initial procedure. Both occurred in patients with postthrombotic obstruction. One patient developed a superficial femoral artery pseudoaneurysm. CONCLUSION: Over half of our patients with open ulcers had stenotic lesions. The ulcers healed in 58% of the stented limbs. That indicates that outflow obstruction may play a significant role in patients with chronic venous stasis symptoms, especially those with open ulcers who failed to respond to other treatment modalities. The procedure itself is relatively safe and simple and can be performed on an ambulatory basis.

PURPOSE: To investigate the molecular mechanisms that lead to inhibition of intimal hyperplasia (IH) following p53 gene therapy. METHODS: In vivo p53 gene transfer to balloon injured rat carotid arteries was performed by utilizing adenovirus. The relationship between p53, p21, retinoblastoma protein (Rb), B-cell lymphoma 2 (Bcl-2), Bax, and Bcl-x was examined by immunohistochemistry. Expression of cyclin D1, Fas/CD95, and poly(ADP-ribose)polymerase (PARP) was determined. RESULTS: Our data indicate increased expression of p53 in the nuclei of vascular smooth muscle cells (VSMCs) in the media (P < .01) compared with the controls. In the treated animals, Bax and Bcl-x, p21, and Rb were significantly upregulated (P < .01). Immunoreactivity to Bcl-2 was observed only in the neointima of untreated groups at 14 days. An increased presence of Fas and decreased expression of PARP was observed in the cytoplasm of the VSMCs of p53-treated animals. CONCLUSIONS: P53 gene transfer activated a battery of downstream effector genes whose products are directly involved in cell cycle arrest, DNA repair, and apoptosis.

OBJECTIVES: Despite advances in endovascular therapies, critical limb ischemia (CLI) continues to be associated with high morbidity and mortality. Patients without direct revascularization options have the worst outcomes. We sought to explore the feasibility of conducting a definitive trial of a bone marrow-derived cellular therapy for CLI in this "no option" population. METHODS: A pilot, multicenter, prospective, randomized, double-blind, placebo-controlled trial for "no option" CLI patients was performed. The therapy consisted of bone marrow aspirate concentrate (BMAC), prepared using a point of service centrifugation technique and injected percutaneously in 40 injections to the affected limb. Patients were randomized to BMAC or sham injections (dilute blood). We are reporting the 12-week data. RESULTS: Forty-eight patients were enrolled. The mean age was 69.5 years (range, 42-93 years). Males predominated (68%). Diabetes was present in 50%. Tissue loss (Rutherford 5) was present in 30 patients (62.5%), and 18 (37.5%) had rest pain without tissue loss (Rutherford 4). Patients were deemed unsuitable for conventional revascularization based on multiple prior failed revascularization efforts (24 [50%]), poor distal targets (43 [89.6%]), and medical risk (six [12.5%]). Thirty-four patients were treated with BMAC and 14 with sham injections. There were no adverse events attributed to the injections. Renal function was not affected. Effective blinding was confirmed; blinding index of 61% to 85%. Subjective and objective outcome measures were effectively obtained with the exception of treadmill walking times, which could only be obtained at baseline and follow-up in 15 of 48 subjects. This pilot study was not powered to demonstrate statistical significance but did demonstrate favorable trends for BMAC versus control in major amputations (17.6% vs 28.6%), improved pain (44% vs 25%), improved ankle brachial index (ABI; 32.4% vs 7.1%), improved Rutherford classification (35.3% vs 14.3%), and quality-of-life scoring better for BMAC in six of eight domains. CONCLUSIONS: In this multicenter, randomized, double-blind, placebo-controlled trial of autologous bone marrow cell therapy for CLI, the therapy was well tolerated without significant adverse events. The BMAC group demonstrated trends toward improvement in amputation, pain, quality of life, Rutherford classification, and ABI when compared with controls. This pilot allowed us to identify several areas for improvement for future trials and CLI studies. These recommendations include elimination of treadmill testing, stratification by Rutherford class, and more liberal inclusion of patients with renal insufficiency. Our strongest recommendation is that CLI studies that include Rutherford 4 patients should incorporate a composite endpoint reflecting pain and quality of life.

Popliteal artery aneurysms represent a common pathology that vascular surgeons are often confronted with. However, several issues remain incompletely understood, including indications for intervention and optimal methods of treatment. In the following article, our discussants debate the appropriate management of small popliteal artery aneurysms. Further complicating this discussion is the unclear relationship between popliteal artery aneurysm diameter and subsequent complications. Whereas with abdominal aortic aneurysms diameter is linked to rupture risk, it is less clear with popliteal artery aneurysms where complications are more likely to include thrombosis, embolization, and compression whether aneurysm diameter is accurately predictive. Perhaps other anatomic features should be included in our management algorithms? Regardless, our debaters will try to convince us whether small popliteal artery aneurysms warrant repair or not.