Faculty Bibliography

OBJECTIVE: Following contemporary trend, various vascular interventions being performed in the office. We describe our office experience with radiofrequency ablation (RFA) of incompetent perforating veins (IPV) and duplex-guided balloon angioplasties of failing/nonmaturing arterio-venous fistulas (AVF). DUPLEX-GUIDED BALLOON ANGIOPLASTIES OF AVF: Eighteen patients with 20 failing arterio-venous (AV) fistulas underwent office duplex-guided balloon angioplasties. Thirteen procedures (65%) were on non-maturing fistulas and the remaining 7 (35%)--in dialyzed patients. Sheath insertion, wire and balloon passage and inflation were guided by duplex only. RFA OF IPVS: We performed 25 radiofrequency ablations of 49 IPVs. Early follow-up scan confirmed total occlusion of 45 (92%) treated IPVs. Patients gender, CEAP class, perforator diameter or GSV patency did not correlate with current procedure failure. CONCLUSION: Excellent duplex imaging quality and technical advances in endovascular tools allowed us safely perform AVF balloon angioplasties and RFA of IPVs in the office.

Office-based procedures have witnessed a veritable explosion with more than 10 million procedures being performed in the United States yearly. This is partially because of improvements in technology that allow these procedures to be performed safely in the office. However, as the number of procedures has increased, the reports of significant morbidity and mortality that have been appearing in the media have captured the public's attention. Until recently, this new and growing field has been largely unregulated. This is changing nationwide. The authors review the new regulations in New York State as a model of the future of this rapidly evolving field and their effect on vascular surgery office procedures.

The Society for Vascular Surgery considers the placement and maintenance of arteriovenous hemodialysis access to be an important component of any vascular surgery practice. Therefore, the Society has long been involved in setting the standards for the management of arteriovenous access. Formulating clinical recommendations in this area is the latest effort by the Society to improve the management of arteriovenous access on a national level. To provide an unbiased study of the evidence and to help in formulating the recommendations, the Society used the Knowledge and Encounter Research (KER) Unit of the Mayo Clinic College of Medicine, Rochester, Minn, to review the available evidence and advise a multidisciplinary group of access surgeons and nephrologists in formulating the clinical recommendations. To review the evidence, randomized and observational study designs were both considered. Whenever possible, systematic reviews and meta-analyses of the literature were used because, compared with individual studies, they generate more precise estimates of treatment effects and their results are applicable to a wider range of patients. On behalf of the Society, the group issued its recommendations following the Grading of Recommendations Assessment, Development and Evaluation (GRADE) format; this format disentangles the strength of recommendations from the quality of the evidence and encourages statements about the underlying values and preferences relevant to the particular recommendation. The recommendations are classified as strong (denoted by the phrase "we recommend") or weak (denoted by the phrase "we suggest"); and the quality of evidence is classified as high, moderate, low, or very low. These recommendations are not meant to supersede clinical judgment; rather, they should be used as a guide for the practicing surgeon and nephrologist as the decision is being made for the placement and subsequent procedures and management of arteriovenous hemodialysis access are being considered.

Recognizing the impact of the decision making by the dialysis access surgeon on the successful placement of autogenous arteriovenous hemodialysis access, the Society for Vascular Surgery assembled a multispecialty panel to develop practice guidelines in arteriovenous access placement and maintenance with the aim of maximizing the percentage and functionality of autogenous arteriovenous accesses that are placed. The Society commissioned the Knowledge and Encounter Research Unit of the Mayo Clinic College of Medicine, Rochester, Minnesota, to systematically review the available evidence in three main areas provided by the panel: timing of referral to access surgeons, type of access placed, and effectiveness of surveillance. The panel then formulated practice guidelines in seven areas: timing of referral to the access surgeon, operative strategies to maximize the placement of autogenous arteriovenous accesses, first choice for the autogenous access, choice of arteriovenous access when a patient is not a suitable candidate for a forearm autogenous access, the role of monitoring and surveillance in arteriovenous access management, conversion of a prosthetic arteriovenous access to a secondary autogenous arteriovenous access, and management of the nonfunctional or failed arteriovenous access. For each of the guidelines, the panel stated the recommendation or suggestion, discussed the evidence or opinion upon which the recommendation or suggestion was made, detailed the values and preferences that influenced the group's decision in formulating the relevant guideline, and discussed technical remarks related to the particular guideline. In addition, detailed information is provided on various configurations of autogenous and prosthetic accesses and technical tips related to their placement.

Currently, the value of stenting during femoropopliteal balloon angioplasty (FPBA) remains unclear. Herein we evaluate the patency rates of successful duplex-guided balloon angioplasty (DAGBA) alone versus suboptimal DAGBA followed by stenting and the prestenting dissection versus recoil as potential indicators of stent success or failure. Over a period of 27 months, we performed 291 duplex-guided FPBAs (194 stenoses; 97 occlusions) on 244 limbs in 220 patients. Disabling claudication was the indication in 67%. Critical limb ischemia was the indication in the remaining 33%. Self-expanding nitinol stents were used when plaque dissection and/ or recoil caused diameter reduction > or = 40%. Serial follow-up duplex scans were obtained. Severe restenosis (> 70%) was measured by B-mode imaging and a peak systolic velocity ratio > 3. Follow-up ranged from 1 to 41 months (mean 10 +/- 8.3 months). The overall mean interval for restenosis and occlusion was 6.5 +/- 4.2 months and 5.6 +/- 6.1 months, respectively. Stents did affect overall patency results compared with not using stents. Reasons for stenting were plaque recoil, dissection, or both in 98 (53%), 44 (24%), and 42 (23%) cases, respectively. Six-month patency was 59%, 94%, and 69%, respectively. The difference between plaque recoil and dissection was significant (p<.04). The use of stents during FPBA may be associated with balloon angioplasty site failure in the femoropopliteal segment. To our knowledge, this is the first report ever to document plaque recoil as a predictor of balloon angioplasty site failure notwithstanding stent placement.

The Society for Vascular Surgery (SVS) appointed a committee of experts to formulate evidence-based clinical guidelines for the management of carotid stenosis. In formulating clinical practice recommendations, the committee used systematic reviews to summarize the best available evidence and the GRADE scheme to grade the strength of recommendations (GRADE 1 for strong recommendations; GRADE 2 for weak recommendations) and rate the quality of evidence (high, moderate, low, and very low quality). In symptomatic and asymptomatic patients with low-grade carotid stenosis (<50% in symptomatic and <60% in asymptomatic patients), we recommend optimal medical therapy rather than revascularization (GRADE 1 recommendation, high quality evidence). In symptomatic patients with moderate to severe carotid stenosis (more than 50%), we recommend carotid endarterectomy plus optimal medical therapy (GRADE 1 recommendation, high quality evidence). In symptomatic patients with moderate to severe carotid stenosis (>/=50%) and high perioperative risk, we suggest carotid artery stenting as a potential alternative to carotid endarterectomy (GRADE 2 recommendation, low quality evidence). In asymptomatic patients with moderate to severe carotid stenosis (>/=60%), we recommend carotid endarterectomy plus medical management as long as the perioperative risk is low (GRADE 1 recommendation, high quality evidence). We recommend against carotid artery stenting for asymptomatic patients with moderate to severe (>/=60%) carotid artery stenosis (GRADE 1 recommendation, low quality evidence). A possible exception includes patients with >/=80% carotid artery stenosis and high anatomic risk for carotid endarterectomy.

OBJECTIVE: Due to the inherent risks, deficiencies and cost associated with contrast arteriography (CA), our group has been utitilizing duplex arteriography (DA) for evaluating the arteries of the lower extremity for patients undergoing lower extremity revascularization. In an effort to further explore the strengths and weaknesses of DA, we reviewed our evolving experience with DA from January 1, 1998, to January 1, 2005. PATIENTS AND METHODS: The arterial segments starting from mid-abdominal aorta to the pedal arteries were studied in cross-sectional and longitudinal planes using a variety of scanheads of 7-4, 10-5, 12-5, 5-2 and 3-2 MHz extended operative frequency range to obtain high-quality B-mode, color and power Doppler images as well as velocity spectra. In 906 patients, 1,020 duplex arteriograms were obtained. The ages ranged from 30-98 years old with a mean of 73+/-11 (SD) years. Fifty percent of the patients were diabetics. Indications for the examination included: tissue loss (409), rest pain (221), claudication (310), acute ischemia (74), popliteal aneurysm (45), SFA aneurysm (2), abdominal aortic aneurysms (AAA) (10) and failing bypass (55). Prior procedures had been performed in 262. DA was performed by six technologists (4 of whom are MDs). In all, 207 DA were performed intraoperatively and the remainder, preoperatively. RESULTS: The resultant procedures based upon DA included: bypass to the popliteal artery (262) and bypass to an infrapopliteal artery (325), endovascular procedures (363), thrombectomy (11), embolectomy (9), inflow bypass procedures to the femoral arteries (46), debridment (4), amputation (8) and no intervention (75). The areas not visualized well included: iliac (73), femoral (26), popliteal (17), and infrapopliteal (221). Additional imaging after DA was deemed necessary in 102 cases to obtain enough information to plan lower extremity revascularization. Factors associated with increased need to obtain CA included: DM (p<.001), infrapopliteal calcification (p<.001), older age (p = .01) and limb threatening ischemia (p<.001). Factors not associated with the need to obtain CA included: which technologist performed the exam, whether the technologist has a medical degree and whether the patient underwent prior revascularization. CONCLUSIONS: In 90% of patients reviewed, DA is able to obtain the needed information to plan lower extremity revascularization. Severe tibial vessel calcification is the most common cause of an incomplete DA exam and determines when alternative imaging modalities need to be obtained.

The role of routine use of duplex arteriography to diagnose thrombosis of popliteal artery aneurysm as a cause of acute lower extremity ischemia is investigated. In all, 109 patients (group 1) from 1994 to 1997 and 201 patients from 1998 to 2001(group 2) presenting with acute limb-threatening ischemia were studied. None of the group 1 patients underwent preoperative duplex arteriography, and no diagnosis of acute popliteal artery aneurysm thrombosis was made. Ten patients with acute ischemia due to thrombosed popliteal artery aneurysm were identified in group 2 when preoperative duplex arteriography was routinely performed. Urgent revascularization was performed based on the results of duplex arteriography. Six patients had functioning bypasses with a mean follow-up of 15.6 months. There were 3 deaths, 2 within 30 days and 1 after 2(1/2) years with functioning grafts. One patient was lost to follow-up. Routine use of duplex arteriography may provide the diagnosis and may identify the available outflow vessels for popliteal artery aneurysm.

OBJECTIVE: This study assessed whether the duplex ultrasound (DUS)-derived gray-scale median (GSM) of the most six distal portion of the occluded femoral-popliteal arterial segment can predict success of lumen re-entry for subintimal angioplasty. METHODS: During the last 3 years, 108 patients (62% men) with a mean age of 73 +/- 10 years underwent 116 primary attempted DUS-guided subintimal angioplasties of the femoral-popliteal segment. Preprocedural B-mode DUS images of the plaque at the most distal occlusion segment were digitalized and normalized using Photoshop (Adobe, San Jose, Calif) software and standard criteria (gray level, 0 to 5 for lumen blood and 185 to 190 for the adventitia on a linear scale of 0 to 255). Overall GSM of the plaque segment about 2 cm long, immediately before the planned re-entry point to the true arterial lumen, was used for retrospective correlation with procedure success and other clinical indicators. RESULTS: Mean plaque GSM for all cases was 22.5 +/- 12.6 (range, 3 to 60). The overall success rate of subintimal angioplasty procedures was 85%. Mean plaque GSM for 99 successful cases (18.4 +/- 7.8) was significantly lower than for 17 cases (46.4 +/- 8.1) where we failed (P < .0001). We failed in 90% of 19 cases with GSM >35, in 71% of 24 cases with GSM >20, and in 50% of 34 cases with GSM >25. There was no statistically significant difference (P = .45) between plaque GSM in 64 patients with diabetes (23.3 +/- 13.5) compared with 52 nondiabetic patients (21.5 +/- 11.4). Similarly, plaque GSM was not statistically different (P = .9) in 52 patients with renal insufficiency (22.7 +/- 13.2) compared with 64 patients with normal creatinine levels (22.4 +/- 12.2). At the 6-month follow-up, no statistically significant difference was found between mean GSM (17.8 +/- 7.8) in 47 stenosis-free cases compared with mean GSM (18 +/- 6.8) in 22 cases where severe restenosis (>70%) or reocclusion was identified by DUS scan (P = .4). CONCLUSIONS: Plaque echogenicity represented by DUS-derived GSM can be used to predict the success of primary subintimal femoral-popliteal angioplasties.