The impact of chronic kidney disease on lower extremity bypass outcomes in patients with critical limb ischemia.

OBJECTIVE: Patient selection for open lower extremity revascularization in patients with chronic kidney disease (CKD) remains a clinical challenge. This study investigates the impact of CKD on early graft failure, postoperative complications, and mortality in patients undergoing lower extremity bypass for critical limb ischemia. METHODS: The National Surgical Quality Improvement Program database was queried for all patients with critical limb ischemia from 2012 to 2015 who underwent lower extremity bypass using the targeted vascular set. The glomerular filtration rate was calculated using the Chronic Kidney Disease Epidemiology Collaboration Study equation. CKD categories were determined from the National Kidney Foundation Kidney Disease Outcomes Quality Initiative staging criteria. Patients were classified into three groups: CKD stages 3 or lower (mild to moderate CKD), CKD stages 4 or 5 (severe CKD), and on hemodialysis (HD). Multiple variable analysis was used to examine graft failure, mortality, and postoperative complications. RESULTS: The Surgical Quality Improvement Program database identified 6978 patients who underwent infrainguinal lower extremity arterial bypass during the study period. There were 6101 patients (87.4%) with mild to moderate CKD, 327 (4.7%) with severe CKD, and 550 (7.9%) on HD. Patients with severe CKD and on HD were more likely to have revascularization for tissue loss (54.9% vs 68.8% and 74.7%; P < .01). Patients with severe CKD and those on HD had higher rates of early graft failure, postoperative myocardial infarction, and rates of reoperation. Multiple variable analysis confirmed these results showing that HD was associated with postoperative myocardial infarction, readmission, and increased mortality. It also demonstrated that severe CKD was associated with graft failure (odds ratio [OR], 1.67; 95% confidence interval [CI], 1.12-2.50; P = .01), postoperative myocardial infarction (OR, 2.16; 95% CI, 1.35-3.45; P < .01), and readmission (OR, 1.38; 95% CI, 1.06-1.80; P = .02). Other factors associated with graft failure include functional status (OR, 1.39; 95% CI, 1.08-1.80; P = .01), African American race (OR, 1.72; 95% CI, 1.39-2.13; P < .01), and distal bypass (OR, 1.33; 95% CI, 1.09-1.61; P < .01). CONCLUSIONS: CKD is a significant predictor of perioperative morbidity after lower extremity bypass. Patients with severe CKD have worse postoperative outcomes without increased mortality. Those on HD have worse survival and postoperative outcomes.

Systematic review and meta-analysis of high-pressure intermittent limb compression for the treatment of intermittent claudication.

BACKGROUND: High-pressure intermittent limb compression (HPILC) has been proposed as an alternative treatment of disabling intermittent claudication. The objective of this study was to conduct a systematic review and meta-analysis of randomized controlled trials evaluating the efficacy of HPILC in improving walking distance in patients with intermittent claudication. METHODS: A search through December 31, 2016, was performed to identify all randomized controlled trials evaluating the efficacy of HPILC for the management of intermittent claudication. Applicable studies were assessed for quality and pooled using Cochrane systematic review guidelines. The primary outcome measured was absolute claudication distance (ACD). A random-effects model was used for meta-analysis. RESULTS: Eight studies eligible for inclusion were identified. These studies had a combined total of 290 subjects, 172 of whom were randomized to HPILC. All studies identified an increase in walking distance for subjects receiving compression therapy. On meta-analysis, the mean difference of ACD from baseline to follow-up among subjects receiving compression compared with controls was 125 m (95% confidence interval, 58.38-191.63 m; P < .01). CONCLUSIONS: HPILC is associated with a significant increase in ACD compared with controls. Limb compression appears to be an effective, noninvasive treatment option for patients with intermittent claudication. However, there are few studies comparing limb compression with other commonly used therapies. Further studies are needed to better guide the use of HPILC in the treatment of claudication.

Reflux in foot veins is associated with venous toe and forefoot ulceration.

OBJECTIVE: To determine the prevalence of foot vein incompetence in a group of patients with chronic venous insufficiency and to assess the association of this, with venous ulceration located on the forefoot. METHODS: A total of 20 consecutive patients (21 limbs) with active or healed venous ulceration was prospectively studied with duplex ultrasound of the superficial and plantar foot veins. In these, four extremities had venous ulceration involving the forefoot. Specifically, the superficial venous arch near the metatarsal heads, the foot portion of the great and small saphenous veins, the anterior arch veins on the foot dorsum, and the plantar veins were interrogated with a 12-MHz probe. RESULTS: Reflux was found in 32% of pedal vein segments in CEAP C5, C6 legs, with ulceration involving only the gaiter area (mean number of incompetent foot segments, 1.6 ± 1.2). Pedal reflux was present in 65% of foot vein segments when forefoot ulceration was present (mean number of incompetent foot segments, 3.3 ± 1.3). Student t-test for the difference in the mean number of incompetent foot vein segments was significant (P < .004). CONCLUSIONS: Venous ulceration can affect the forefoot and toe areas and is associated with reflux in the pedal vein segments.

Long-Term Outcomes of Fistula First Initiative in an Urban University Hospital-Is It Still Relevant?

PURPOSE: Dialysis access failure is a major cause of morbidity in patients with end-stage renal disease. The Fistula First Breakthrough Initiative (FFBI) dictates arteriovenous fistulae (AVFs) should be preferred over arteriovenous grafts (AVGs) as first line for surgically placed accesses. The purpose of this study was to compare patency rates of surgical dialysis accesses in our mature, urban population after the FFBI. METHODS: Current dialysis patients with accesses placed between 2006 and 2011 were included. Patient characteristics, access outcomes, interventions, and survival outcomes were analyzed. RESULTS: We report outcomes of 220 patients undergoing dialysis access. Of those 220, 75 received numerous accesses. All outcomes are evaluated as per access itself, that is, a patient may have numerous access types, each individually analyzed. Of the accesses, 138 were AVF and 190 were AVG. The average age of patients was 59.8 years. The groups were evenly matched in distribution of race and prevalence of hypertension, diabetes, coronary artery disease, and Peripheral Vascular Disease (PVD). Average number of complications requiring intervention per access were fewer with AVF than AVG (1.21 vs 1.72, P = .02). The AVF had greater rates of stenosis (51.4% vs 40.6%, P = .0182), whereas AVG had greater thrombosis rates (14.6% vs 31.9%, P < .001). Both AVF and AVG had similar primary patency (median: 186 vs 142 days, P = .1774) and 3-year secondary patency (59.2% vs 49.2%, P = .0945). Arteriovenous fistula in patients aged <60 years was found to have the greatest primary ( P = .0078) and secondary patency ( P = .0400). Outcomes did not differ between AVF and AVG in those aged >60 years. CONCLUSIONS: Although complications requiring intervention are greater with AVG, primary and secondary patency rates are similar between AVF and AVG, except when considering AVF in patients aged <60 years.

Mapping of superficial extremity veins: normal diameters and trends in a vascular patient-population.

Ultrasonic measurement of superficial extremity veins is a common procedure. To establish normal values for vein-size in a population of vascular patients and to assess if measurements remain unchanged over time, we analyzed a database with results of 28,130 measurements in 2420 separate saphenous and 3206 cephalic veins. Mean size of the great saphenous vein ranges from 2.3 mm to 4.4 mm but did not follow a tapering pattern as is often assumed. The distal calf segment is smaller than the ankle segment. The mean cephalic vein size in the upper arm (2.4 mm) was smaller than at the antecubital level (2.7 mm). A decrease in vein diameter over time was noted in many locations and this reached statistical significance (p < 0.005 for the thigh segment). The clinical significance of this is a need to repeat ultrasonic vein-mapping if more than a year elapses between ultrasound and surgical vein harvest.

Improvement in the visualization of superficial arm veins being evaluated for access and bypass.

OBJECTIVES: Duplex ultrasound mapping of arm veins is being performed with increasing frequency. Unlike ultrasound testing in other areas, this has never been subjected to a gold standard invasive test to determine accuracy. Duplex mapping appears to have a good predictive value whenever large veins are demonstrated preoperatively, but its ability to accurately measure minimum-sized veins is unproven. In this study, we compared diameter measurements obtained under six different conditions and used the maximum diameter as the comparison gold standard. METHODS: A 12-MHz linear probe was used to measure the cephalic and basilic vein cross-sectional diameters at the wrist level in 24 normal volunteers under the following conditions: (1) resting supine with a room temperature of 23 degrees to 24 degrees C, (2) supine with a tourniquet inflated to 65 mm Hg, (3) sitting with the arm dangling, (4) sitting with a tourniquet, (5) sitting after a 2-minute immersion in warm water (44 degrees C), and (6) same with tourniquet. Half the subjects underwent the protocol in a different order. RESULTS: Vein diameters were significantly larger after submersion in warm water compared with supine (P < .05, pair-wise multiple comparison procedure, Student-Newman-Keuls method). Assuming the sitting position (from supine) resulted in a decreased arm vein diameter 58% of the time. In 25% of the normal subjects, the cephalic vein size was <2 mm, which increased to >2 mm after warming. All subjects had either a cephalic or a basilic vein at the wrist that was >3.1 mm after warming. CONCLUSION: Use of warm water immersion before vein diameter measurement in a sitting position, without a tourniquet, will result in significantly larger diameter findings in normal arm veins. These diameters are likely to more closely resemble the venous diameter after distension with arterial pressure. Further studies are needed to see if warming in patients could result in increased utilization of autogenous arm vein for dialysis access and bypass.

Angiographic improvement after rapid intermittent compression treatment [ArtAssist] for small vessel obstruction.

A case is presented of a female ex-smoker who underwent bypass or exploration of all three below-knee arteries with failed results. Three separate arteriograms, performed at other academic institutions, demonstrated progressive, severe involvement of the pedal arteries. Therefore, the patient was prepared to undergo below-knee amputation surgery for uncontrollable rest pain and progressive necrosis of the forefoot; instead, the patient underwent 4 months of intermittent compression treatment. A fourth arteriogram, performed after 4 months of intermittent compression treatment (using rapid inflation/deflation and high-pressure cycle; ArtAssist demonstrated marked improvement of the posterior tibial artery runoff and development of more extensive collateral arteries in the calf. The patient's rest pain subsided and successful limb salvage was accomplished with a modified transmetatarsal amputation. This case could encourage other practitioners to repeat arteriography after compression treatments, which may redirect the treatment plan for selected patients with critical limb ischemia and nonreconstructable peripheral vascular disease.

Impaired hyperemic response is predictive of early access failure.

The aim of this study was to demonstrate that hyperemic response is a predictor of access failure. We conducted a review of a prospective database of dialysis access patients with preoperative hyperemia studies from June 1998 to August 2002. These consisted of bilateral brachial artery pressures followed by flow velocity measurements of the brachial artery and radial artery at rest and after 3 min of arm ischemia. Measurements were taken by using a cuff placed above the antecubital fossa and inflated to 20 mmHg above systolic pressure. There were no differences recorded in brachial artery pressures for the bilateral studies. Hyperemic response was entered into a stepwise Cox regression to determine its effect on access failure. Access failure was defined as failure to mature or thrombosis. Accesses were placed according to Dialysis Outcome Quality Intiatives (DOQI) guidelines. Kaplan-Meier survival analysis was performed. Log-rank testing was used to compare patency results. Censored end points were death, renal transplant, and access survival to the end of the study period. Fistulas that failed to mature were considered failures at 3 months. Arteries with a <5 cm/sec increase in peak systolic velocity were defined as nonresponders. The 59 arteries used for dialysis access were divided into two groups on the basis of their hyperemic response in cm/sec. The nonresponders were compared with the remainder of accesses performed. Accesses based on arteries with absent or minimal hyperemic response had significantly lower (p < 0.0005) secondary patencies by Kaplan-Meier analysis. Upon further stratification into radial and brachial arteries, the significant difference in secondary patency remained for radial artery--based accesses (p = 0.024) and approached statistical significance for brachial artery--based accesses (p = 0.057). A significant difference was not seen in primary patencies, indicating that accesses based on arteries with an acceptable hyperemic response are more likely to be salvaged by revisions. A nonresponsive radial artery was not a significant predictor of a nonresponsive brachial artery in the same extremity by binary logistic regression (p = 0.111), and a nonresponsive artery was not a significant predictor of nonresponsiveness in the corresponding artery in the contralateral extremity (p = 0.137). Cox regression analysis revealed that the hyperemic response is a significant predictor of failure to mature or thrombosis. Hyperemic testing is a useful means of evaluating adequate arterial inflow for dialysis access. Reduced or absent hyperemic response is an independent predictor of access failure.

High-risk carotid endarterectomy: fact or fiction.

OBJECTIVE: It has been proposed that patients whose conditions do not meet North American Symptomatic Carotid Endarterectomy Trial inclusion criteria or have anatomic risk factors constitute a "high-risk" group for carotid endarterectomy (CEA) and might be candidates for primary carotid angioplasty stenting. Our objective was to review a consecutive series of isolated CEAs, identify the number of such patients at high risk, and determine whether their operations were associated with increased complication rate. METHODS: Consecutive isolated CEAs performed between June 1996 and June 2001 were reviewed. High-risk comorbidities included: age 80 years or more (n = 80), New York Heart Association class III/IV angina (n = 16), Canadian class III/IV heart failure (n = 4), myocardial infarct 6 months or less (n = 11), steroid-dependent or oxygen-dependent pulmonary disease (n = 4), and creatinine level of 3 or more (n = 13). Anatomic high risk was defined by: contralateral occlusion (n = 66), lesion above C(2) or requirement of digastric division (n = 53), reoperation (n = 29), and neck radiation (n = 3). Statistical analysis was with chi(2) analysis. RESULTS: Of 788 patients reviewed, 228 (29%) were classified as high risk by one or more of the previous criteria (63% comorbidity, 28% anatomy, 9% both). Presence of preoperative neurologic symptoms and postoperative results were similar across all patient groups. The total stroke and death rate was 1.1% for all the patients. Six patients had postoperative strokes (0.8%), and three patients died of myocardial infarcts (0.4%). The stroke and death rate was 1.3% in the high-risk group as compared with 1.1% in the normal-risk group (P =.51). CONCLUSION: The concept of the high-risk CEA must be critically reexamined. Although 29% of patients for CEA were high risk as defined by others, we found no evidence that this influenced the results after CEA. Patients with significant medical comorbidities, contralateral carotid occlusion, and high carotid lesions can undergo operation without increased complications. If a high-risk group exists, it is small and restricted to reoperation or radiated neck (4% in this series). With this possible exception, carotid angioplasty stenting should be restricted to randomized clinical trials.