Two new species of Bimastos (Oligochaeta, Lumbricidae) from the Southern Appalachian Mountains, North America.

Two new species of Bimastos Moore are described based on morphological and molecular data. Bimastos nanae n. sp. resembles B. lawrenceae Fender, B. zeteki (Smith and Gittins) and B. welchi (Smith). Bimastos nanae n. sp. differs from these species in the position of the clitellum, size and number and position of thickened septa. Bimastos magnum n. sp. is similar to B. schwerti Csuzdi Chang and B. palustris Moore in having a fully annular clitellum and male pores on huge porophores. Bimastos magnum n. sp. differs from both species by having a more posterior position of the clitellum (in xxiv-xxxiii, xxxiv) and larger body size. With the description of these new species, the number of Bimastos species is raised to 14.

Myriapoda of Canada.

The currently documented fauna of described species of myriapods in Canada includes 54 Chilopoda, 66 Diplopoda, 23 Pauropoda, and two Symphyla, representing increases of 24, 23, 23, and one species, respectively, since 1979. Of the 145 myriapod species currently documented, 40 species are not native to Canada. The myriapods have not been well documented with DNA barcodes and no barcodes are available for Pauropoda. It is conservatively estimated that at least 93 additional myriapods species will be discovered in Canada: Chilopoda (40), Diplopoda (29), Pauropoda (17), and Symphyla (seven). In general, there is a serious dearth of knowledge about myriapods in Canada, and systematics research and surveys continue to be needed to help document the diversity and distribution of these groups in the country.

Asian pheretimoid earthworms in North America north of Mexico: An illustrated key to the genera Amynthas, Metaphire, Pithemera, and Polypheretima (Clitellata: Megascolecidae).

The invasion of the pheretimoid earthworms in North America, especially the genera Amynthas and Metaphire, has raised increasing concerns among ecologists and land managers, in turn increasing the need for proper identification. However, the commonly used keys to this group are more than 30 years old with outdated taxonomic information and are based primarily on internal morphology. The requirement of significant amount of taxonomic expertise and dissection, even from the first entry of the key, has prevented broader use of these keys. As a result, many publications in the United States have used Amynthas spp. to represent the group without identifying the species. We present here a new key and diagnoses for the 16 pheretimoid earthworm species recorded in North America north of Mexico, including four genera: Amynthas (10), Metaphire (4), Pithemera (1), and Polypheretima (1). The descriptions were based on published records with modifications following inspection of specimens archived at the National Museum of Natural History, Smithsonian Institution, Washington, D.C. Photos of external and internal characters, including male pores, spermathecal pores, genital markings, spermathecae, prostate glands, and intestinal caeca, are presented to help identification. A summary of current knowledge about the ecology and historical context is provided for each species. We also highlight the previously overlooked and potentially common and widespread co-occurrence of three species-A. agrestis, A. tokioensis, and M. hilgendorfi-and point out that many recent claims of invasion of A. agrestis need to be re-evaluated for potential misidentification.

First report of Amynthas carnosus (Goto & Hatai, 1899) (Oligochaeta: Megascolecidae) in the Western Hemisphere.

The earthworm fauna of North America is still greatly unknown, with undescribed native species and new records of invasive species continually being discovered. The most recent checklists are difficult to reconcile, since they vary in their geographic coverage and taxonomy. Reynolds & Wetzel (2012) state that North America (including all of Mexico, some of the Caribbean, and Hawaii) is home for 256 species of earthworms, from which 188 are considered native or endemic and 68 are peregrine, exotic, and invasive species. Blakemore (2008) listed North America north of Mexico as having 183 earthworm species, of which 59 species are exotic. One Megascolecidae genus, Amynthas, is mostly located in the warmer subtropical and tropical regions of the world, with a few species that are able to survive the winter in the temperate zones of North America (Edwards & Bohlen 1995; Görres et al. 2014). Here we report for the first time the occurrence of Amynthas carnosus (Goto & Hatai, 1899) in the United States. To our knowledge, this is not only the first report of A. carnosus in North America, but also its first report in the Western Hemisphere. The description below is intended to place our specimens in the correct taxon while avoiding future confusion with similar species, without making changes to the existing classification system.

Characterization of fracture behavior of human atherosclerotic fibrous caps using a miniature single edge notched tensile test.

UNLABELLED: One well-established cause of ischemic stroke is atherosclerotic plaque rupture in the carotid artery. Rupture occurs when a tear in the fibrous cap exposes highly thrombogenic material in the lipid core. Though some fibrous cap material properties have been measured, such as ultimate tensile strength and stress-strain responses, there has been very little, if any, data published regarding the fracture behavior of atherosclerotic fibrous caps. This study aims to characterize the qualitative and quantitative fracture behavior of human atherosclerotic plaque tissue obtained from carotid endarterectomy samples using two different metrics. Uniaxial tensile experiments along with miniature single edge notched tensile (MSENT) experiments were performed on strips of isolated fibrous cap. Crack tip opening displacement (CTOD) and stress in the un-cracked segment (UCS) were measured at failure in fibrous cap MSENT specimens subjected to uniaxial tensile loading. Both CTOD and the degree of crack blunting, measured as the radius of curvature of the crack tip, increased as tearing propagated through the tissue. Higher initial stress in the UCS is significantly correlated with higher collagen content and lower macrophage content in the fibrous cap (ρ=0.77, P=0.009; ρ=-0.64, P=0.047; respectively). Trends in the data show that higher CTOD is inversely related to collagen content, though the sample size in this study is insufficient to statistically substantiate this relationship. To the authors' knowledge, this is the pioneering study examining the fracture behavior of fibrous caps and the first use of the CTOD metric in vascular tissue. STATEMENT OF SIGNIFICANCE: A tear in the fibrous cap of atherosclerotic plaque can lead to ischemic stroke or myocardial infarction. While there is some information in the literature regarding quantitative measures of fibrous cap failure, there is little information regarding the behavior of the tissue during failure. This study examines the failure behavior of fibrous caps both qualitatively, by examining how and where the tissue fails, and quantitatively, by measuring (a) crack tip opening displacement (CTOD) in vascular tissue for the first time and (b) uniaxial stress in the un-cracked segment (UCS). This study shows that both metrics should be evaluated when assessing plaque vulnerability.

Dietary flexibility aids Asian earthworm invasion in North American forests.

On a local scale, invasiveness of introduced species and invasibility of habitats together determine invasion success. A key issue in invasion ecology has been how to quantify the contribution of species invasiveness and habitat invasibility separately. Conventional approaches, such as comparing the differences in traits and/or impacts of species between native and/or invaded ranges, do not determine the extent to which the performance of invaders is due to either the effects of species traits or habitat characteristics. Here we explore the interaction between two of the most widespread earthworm invaders in the world (Asian Amynthas agrestis and European Lumbricus rubellus) and study the effects of species invasiveness and habitat invasibility separately through an alternative approach of "third habitat" in Tennessee, USA. We propose that feeding behaviors of earthworms will be critical to invasion success because trophic ecology of invasive animals plays a key role in the invasion process. We found that (1) the biomass and isotopic abundances (delta13C and delta15N) of A. agrestis were not impacted by either direct effects of L. rubellus competition or indirect effects of L. rubellus-preconditioned habitat; (2) A. agrestis disrupted the relationship between L. rubellus and soil microorganisms and consequently hindered litter consumption by L. rubellus; and (3) compared to L. rubellus, A. agrestis shifted its diet more readily to consume more litter, more soil gram-positive (G+) bacteria (which may be important for litter digestion), and more non-microbial soil fauna when soil microorganisms were depleted. In conclusion, A. agrestis showed strong invasiveness through its dietary flexibility through diet shifting and superior feeding behavior and its indirectly negative effect of habitat invasibility on L. rubellus via changes in the soil microorganism community. In such context, our results expand on the resource fluctuation hypothesis and support the superior competitor hypothesis. This work presents additional approaches in invasion ecology, provides some new dimensions for further research, and contributes to a greater understanding of the importance of interactions between multiple invading species.

Comparison of interventional outcomes according to preoperative indication: a single center analysis of 2,240 limb revascularizations.

BACKGROUND: Outcomes after lower extremity revascularization are usually reported according to the level of peripheral arterial disease (PAD, aortoiliac or infrainguinal) or the method of treatment (open or endovascular surgery). Outcomes stratified by indication, ie, claudication or critical limb ischemia (rest pain and tissue loss), have not been well studied. The purpose of this study was to compare postoperative outcomes according to the preoperative indications. STUDY DESIGN: Outcomes of 2,240 consecutive limb revascularizations in 1,732 patients from January 1998 through December 2005 were stratified and examined according to preoperative indication: claudication (n=999 limbs), ischemic rest pain (n=464 limbs), or tissue loss (n=777 limbs). End points measured included primary and secondary interventional or operative patency, limb salvage, survival, amputation-free survival, maintenance of ambulation, maintenance of independence, and resolution of presenting symptoms. RESULTS: The proportion of medical comorbidities and the severity of disease increased significantly by cohort from claudication to rest pain to tissue loss. With a mean followup of 1,089 days (range 0 to 3,689 days), overall outcomes performance declined consistently according to indication for all end points measured at 5 years (claudication, rest pain, tissue loss, p value): secondary reconstruction patency (93%, 80%, 66%, respectively; p < 0.001), limb salvage (99%, 81%, 68%, respectively; p < 0.001), survival (78%, 46%, 30%, respectively; p < 0.001), amputation-free survival (78%, 42%, 25%, respectively; p < 0.001), maintenance of ambulation (96%, 78%, 68%, respectively; p < 0.001), maintenance of independence (98%, 85%, 75%, respectively; p < 0.001), and resolution of presenting symptoms (79%, 61%, 42%, respectively; p < 0.001). CONCLUSIONS: There is a declining spectrum of outcomes performance from claudication to rest pain to tissue loss. These findings question the accuracy of all previously published data for critical limb ischemia, for which rest pain and tissue loss are usually blended and reported as a single outcomes value.

Contemporary outcomes of iliofemoral bypass grafting for unilateral aortoiliac occlusive disease: a 10-year experience.

Current treatment of complex aortoiliac occlusive disease (AIOD) includes the aortobifemoral bypass or the femoral-femoral bypass. However, because of bilateral groin exposure and associated risks, there is a significant morbidity associated with these procedures. In appropriate patients with unilateral AIOD, the iliofemoral bypass graft (IFBPG) via a lower abdominal retroperitoneal incision can be an acceptable alternative. The purpose of this study is to review the safety and efficacy as well as long-term outcomes of IFBPG in patients with unilateral AIOD. From July 1997 through June 2006, 40 patients (64.3 +/- 11.2-years-old, range 41-89-years-old, 57.5% critical limb ischemia, 70% male, 95% smokers) with unilateral AIOD were treated with IFBPG. Perioperative complications and symptom resolution were measured and Kaplan-Meier life table analysis was used to analyze outcomes of primary and secondary patency, survival, limb salvage, contralateral intervention, and maintenance of ambulation and independent living status. The perioperative complication rate was 12.5 per cent (n = 5) including one patient who developed atrial-fibrillation and one who developed acute renal failure. Both patients experienced resolution of these symptoms before discharge. Other complications included one limb thrombosis and two wound infections. There were no perioperative deaths. Secondary patency was 97.5 per cent and 93.3 per cent at 1 and 5 years. Limb salvage in patients with critical limb ischemia (CLI) was 85.1 per cent and 79.1 per cent at 1 and 5 years. Limb amputation occurred due to infection (n = 2), or failed IFBPG (n = 2). Thirty-one patients (77.5%) experienced symptom resolution including 15 (88.2%) of the patients treated for claudication. Two patients (5%) required contralateral iliac intervention. Patient survival was 97.5 per cent and 64.5 per cent at 1 and 5 years. Greater than 90 per cent of patients maintained their functional independence at 5 years. IFBPG achieved excellent technical and functional outcomes, particularly in patients treated for vasculogenic claudication. This procedure is relatively safe and efficacious in a population of patients with complex unilateral AIOD and can be an acceptable alternative to the aortobifemoral bypass or fem-fem procedure.

Do current outcomes justify more liberal use of revascularization for vasculogenic claudication? A single center experience of 1,000 consecutively treated limbs.

BACKGROUND: The purpose of this study was to reconsider current recommended treatment guidelines for vasculogenic claudication by examining the contemporary results of surgical intervention. STUDY DESIGN: We performed a retrospective review of 1,000 consecutive limbs in 669 patients treated for medically refractory vasculogenic claudication and prospectively followed. Outcomes measured included procedural complication rates, reconstruction patency, limb salvage, maintenance of ambulatory status, maintenance of independent living status, survival, symptom resolution, and symptom recurrence. RESULTS: Of the 1,000 limbs treated, endovascular therapy was used in 64.3% and open surgery in 35.7% of patients; aortoiliac occlusive disease was treated in 70.1% and infrainguinal disease in 29.9% of patients. The overall 30-day periprocedural complication rate was 7.5%, with no notable difference in complication rates when comparing types of treatment or levels of disease. Overall reconstruction primary patency rates were 87.7% and 70.8%; secondary patencies were 97.8% and 93.9%; limb salvage, 100% and 98.8%; and survivals, 95.4% and 76.9%, at 1 and 5 years, respectively. More than 96% of patients maintained independence and ambulatory ability at 5 years. Overall symptom resolution occurred in 78.8%, and symptom recurrence occurred in 18.1% of limbs treated, with slightly higher resolution and recurrence noted in patients treated with endovascular therapy. CONCLUSIONS: Contemporary treatment of vasculogenic claudication is safe, effective, and predominantly endovascular. These data support a more liberal use of revascularization for patients with claudication and suggest that current nonoperative treatment guidelines may be based more on surgical dogma than on achievable outcomes.

The mid-thigh loop arteriovenous graft: patient selection, technique, and results.

As patient longevity on hemodialysis has increased, surgeons are increasingly challenged to provide vascular access to patients who have exhausted options for access in the upper extremity. A common operation performed on these patients has been the loop thigh arteriovenous (AV) graft based off the common femoral vessels. However, there are several disadvantages of placing prosthetic grafts in proximity to the groin. Our group has modified the thigh loop AV graft procedure by moving the anastomoses to the mid-superficial femoral artery and vein. The advantage of this location is that it preserves the proximal femoral vessels for graft revision and avoids the node-bearing tissue and overhanging panniculus of the groin. The purpose of this study was to review our technique, patient selection, and experience with the mid-thigh loop AV graft procedure. Between 2001 and 2003, 46 mid-thigh loop AV grafts were placed in 38 patients. Patient hospital, office, and dialysis clinic records were reviewed. The primary and secondary patency for AV grafts in this study by life-table was 40 per cent and 68 per cent at 1 year and 18 per cent and 43 per cent at 2 years. There were 10 infections (21%) requiring graft removal. Four patients underwent subsequent placement of a proximal loop thigh AV graft after mid-thigh graft failure. Patient survival was 86 per cent at 1 year and 82 per cent at 2 years. There were no patient deaths related to thigh graft placement. Our results with the mid-thigh loop AV graft compare favorably with published results for thigh loop AV grafts. The procedure preserves the proximal vasculature, permitting graft revision or subsequent proximal graft placement, and may be associated with fewer infectious complications. The mid-thigh loop AV graft procedure should be considered before placement of a thigh loop AV graft based off the common femoral artery and vein.

Does obesity predict functional outcome in the dysvascular amputee?

Limited information is available concerning the effects of obesity on the functional outcomes of patients requiring major lower limb amputation because of peripheral arterial disease (PAD). The purpose of this study was to examine the predictive ability of body mass index (BMI) to determine functional outcome in the dysvascular amputee. To do this, 434 consecutive patients (mean age, 65.8 +/- 13.3, 59% male, 71.4% diabetic) undergoing major limb amputation (225 below-knee amputation, 27 through-knee amputation, 132 above-knee amputation, and 50 bilateral) as a complication of PAD from January 1998 through May 2004 were analyzed according to preoperative BMI. BMI was classified according to the four-group Center for Disease Control system: underweight, 0 to 18.4 kg/m2; normal, 18.5 to 24.9 kg/m2; overweight, 25 to 29.9 kg/m2; and obese, > or = 30 kg/m2. Outcome parameters measured included prosthetic usage, maintenance of ambulation, survival, and maintenance of independent living status. The chi2 test for association was used to examine prosthesis wear. Kaplan-Meier curves were constructed to assess maintenance of ambulation, survival, and maintenance of independent living status. Multivariate analysis using the multiple logistic regression model and a Cox proportional hazards model were used to predict variables independently associated with prosthetic use and ambulation, survival, and independence, respectively. Overall prosthetic usage and 36-month ambulation, survival, and independent living status for the entire cohort was 48.6 per cent, 42.8 per cent, 48.1 per cent, 72.3 per cent, and for patients with normal BMI was 41.5 per cent, 37.4 per cent, 45.6 per cent, and 69.5 per cent, respectively. There was no statistically significant difference in outcomes for overweight patients (59.2%, 50.7%, 52.5%, and 75%) or obese patients (51.8%, 46.2%, 49.7%, and 75%) when compared with normal patients. Although there were significantly poorer outcomes for underweight patients for the parameters of prosthetic usage when compared with the remaining cohort (25%, P = 0.001) and maintenance of ambulation when compared with overweight patients (20.8%, P = 0.026), multivariate analysis adjusting for medical comorbidities and level of amputation showed that BMI was not a significant independent predictor of failure for any outcome parameter measured. In conclusion, BMI failed to correlate with functional outcome and, specifically, obesity did not predict a poorer prognosis.

Is surgical thrombectomy to salvage failed autogenous arteriovenous fistulae worthwhile?

The Dialysis Outcomes Quality Initiatives guidelines emphasize placement of autogenous arteriovenous (AV) fistulae for patients on hemodialysis. This recommendation is based on studies that demonstrate enhanced patency for AV fistulae compared with grafts. However, closer review of the data demonstrates that although primary patency of AV fistulae is superior to grafts, the secondary patency rates are equivalent. This suggests that secondary procedures to maintain fistula patency are inferior to those performed on arteriovenous grafts. Surgical thrombectomy of AV fistulae can be challenging. It is often difficult to completely remove thrombus adjacent to the anastomosis of the fistula, and pseudoaneurysms within the fistula can prevent passage of the thrombectomy catheter and complete removal of thrombus from the fistula. Consequently, some surgeons simply abandon thrombosed AV fistulae and place a new access. We have developed a method for completely clearing thrombus from failed AV fistulae by locating the fistulotomy close to the arterial anastomosis and using a technique to manually extract thrombus from the fistula before passing a thrombectomy catheter. The purpose of this study was to review our results with this procedure. Between 2001 and 2004, 10 patients with a previously functioning AV fistula presented with thrombosis. There were seven brachiocephalic fistulae and three radiocephalic fistulae. All patients underwent surgical thrombectomy and fistulography. Five patients underwent balloon angioplasty of a venous stenosis and one patient underwent surgical revision of an arterial stenosis. Technical success, defined as being able to completely clear thrombus from the fistula and treat the cause for fistula failure, was achieved in 70 per cent (7/10) of cases. Technical failure was caused by vein rupture during the balloon angioplasty in two cases and a central venous occlusion that could not be treated in one case. The 6-month primary and secondary patency for cases that were technically successful was 51 and 69 per cent, respectively. Our conclusion was that surgical thrombectomy can significantly extend fistula functionality in patients who present with thrombosis.

Postoperative outcomes according to preoperative medical and functional status after infrainguinal revascularization for critical limb ischemia in patients 80 years and older.

The purpose of this study was to provide outcomes after intervention for critical limb ischemia (CLI) in elderly patients (> or =80 years) according to medical and functional status at presentation. From January 1998 to September 2003, 140 limbs/122 patients (age range 80-97 years) were treated (57 patients/66 limbs, infrainguinal bypass; 65 patients/74 limbs, infrainguinal angioplasty) for CLI. At presentation, 71 (58.2%) patients were functionally ambulatory, 41 (33.6%) were homebound ambulators, and 10 (8.2%) were transfer-only ambulators. Overall end points after treatment as well as outcomes according to type of treatment and preoperative medical and functional status were determined. End points included reconstruction patency, limb salvage, survival, amputation-free survival, and maintenance of ambulatory and independent living status. Results for the 140 limbs/122 patients at 3 years (Kaplan-Meier curves) include primary patency, 55.3%; secondary patency, 73.2%; limb salvage, 78.3%; survival, 62.5%; amputation-free survival, 49.7%; maintenance of ambulation, 77.8%; and maintenance of independent living status, 82.9%. There was essentially no difference in outcomes based on type of treatment (endovascular vs open operation). When analyzing 2-year outcomes by functional status (ambulatory vs homebound vs transfer), there was deterioration in outcomes according to declining functional status at presentation for mortality (84.7% vs 66.4% vs 42%; P < 0.001), amputation-free survival (73.3% vs 48.2% vs 36.9%; P < 0.001), limb salvage (86% vs 66.5% vs 71.9%; P = 0.022), and secondary patency (84.3% vs 61.5% vs 69.2%; P = 0.005) regardless of treatment. Homebound ambulators were two times and transfer-only patients five times more likely to experience death (Cox hazard model); diabetics were four times more likely to lose a limb and experience a decline in ambulation and living status. Overall medical and functional status at presentation predicts postoperative functional outcomes. These data support a policy of aggressive vascular intervention in the functional elderly and clinical restraint in the functionally impaired patient with CLI.

Preoperative clinical factors predict postoperative functional outcomes after major lower limb amputation: an analysis of 553 consecutive patients.

BACKGROUND: Despite being a major determinant of functional independence, ambulation after major limb amputation has not been well studied. The purpose, therefore, of this study was to investigate the relationship between a variety of preoperative clinical characteristics and postoperative functional outcomes in order to formulate treatment recommendations for patients requiring major lower limb amputation. METHODS: From January 1998 through December 2003, 627 major limb amputations (37.6% below knee amputations, 4.3% through knee amputations, 34.5% above knee amputations, and 23.6% bilateral amputations) were performed on 553 patients. Their mean age was 63.7 years; 55% were men, 70.2% had diabetes mellitus, and 91.5% had peripheral vascular disease. A retrospective review was performed correlating various preoperative presenting factors such as age at presentation, race, medical comorbidities, preoperative ambulatory status, and preoperative independent living status, with postoperative functional endpoints of prosthetic usage, survival, maintenance of ambulation, and maintenance of independent living status. Kaplan-Meier survival curves were constructed and compared by using the log-rank test. Odds ratios (OR) and hazard ratios (HR) with 95% confidence intervals were constructed by using multiple logistic regressions and Cox proportional hazards models. RESULTS: Statistically significant preoperative factors independently associated with not wearing a prosthesis in order of greatest to least risk were nonambulatory before amputation (OR, 9.5), above knee amputation (OR, 4.4), age > 60 years (OR, 2.7), homebound but ambulatory status (OR, 3.0), presence of dementia (OR, 2.4), end-stage renal disease (OR, 2.3), and coronary artery disease (OR, 2.0). Statistically significant preoperative factors independently associated with death in decreasing order of influence included age > or = 70 years (HR, 3.1), age 60 to 69 (HR, 2.5), and the presence of coronary artery disease (HR, 1.5). Statistically significant preoperative factors independently associated with failure of ambulation in decreasing order of influence included age > or = 70 years (HR, 2.3), age 60 to 69 (HR, 1.6), bilateral amputation (HR, 1.8), and end-stage renal disease (HR, 1.4). Statistically significant preoperative factors independently associated with failure to maintain independent living status in decreasing order of influence included age > or = 70 years (HR, 4.0), age 60 to 69 (HR, 2.7), level of amputation (HR, 1.8), homebound ambulatory status (HR, 1.6), and the presence of dementia (HR, 1.6). CONCLUSIONS: Patients with limited preoperative ambulatory ability, age > or = 70, dementia, end-stage renal disease, and advanced coronary artery disease perform poorly and should probably be grouped with bedridden patients, who traditionally have been best served with a palliative above knee amputation. Conversely, younger healthy patients with below knee amputations achieved functional outcomes similar to what might be expected after successful lower extremity revascularization. Amputation in these instances should probably not be considered a failure of therapy but another treatment option capable of extending functionality and independent living.

The surgically created arteriovenous fistula: a forgotten alternative to venous access.

The care of patients requiring lifelong intravenous access was revolutionized with the development of tunneled catheters and implantable ports. These devices are not without complications, however, and selected patients may benefit from alternative modalities to maintain access for such therapies as parenteral nutrition, phlebotomy, or chemotherapy. Use of surgically created arteriovenous (AV) fistulae as an alternative to central venous access has been described. This report reviews our experience using AV access for central venous access. An AV access database of more than 800 active patients was reviewed and all patients who had autogenous or synthetic AV fistulae created exclusively for central venous access between July 1, 2001, and December 31, 2003, were identified. Outcomes were assessed. A total of 853 new accesses were placed during the time period. Six fistulae in six patients (0.7%) were placed for central access. All patients (5 males, 1 female, mean age, 42.8 years) required access for intermittent parenteral nutrition or intravenous fluids secondary to short-gut syndrome (n = 5) or gastroparesis (n = 1). All patients had failed at least two prior catheter-based accesses before access placement was considered. Procedures were all brachial artery based and included autogenous brachiobasilic vein fistulae with elevation or transposition (n = 3), autogenous brachiocephalic fistula (n = 1), autogenous brachiobasilic graft with transposed greater saphenous vein (n = 1), and a prosthetic brachiobasilic graft with ePTFE (n = 1). There was one perioperative autogenous fistula thrombosis treated with thrombectomy and revision. A total of seven late revisions (thrombectomy, thrombectomy with venous outflow revision, fistula elevation, and 4 percutaneous angioplasties) in four patients were required. All fistulae were patent and functional at the end of the review period (mean follow-up, = 393 days; range, 35-757 days). Daily access was performed by family members (n = 2) or nurses (n = 4). One patient received small bowel transplantation and no longer required use of his patent fistula. One patient died of liver failure 382 days after fistula placement with a patent fistula. These results show that, while often forgotten and infrequently used, AV access can be a durable alternative to catheter-based venous access.

Can carotid angiography be performed by vascular surgeons? A critical evaluation of indications, technique, and results.

The purpose of this report is to examine the contemporary indications for diagnostic carotid arteriography and evaluate its utility and safety when performed by vascular surgeons. The records of all patients having selective carotid arteriography from September 2000 through March 2002 at our institution were reviewed. One hundred sixty-four consecutive patients had selective arteriography of the extracranial carotid arteries for the following indications: hemispheric symptoms with stenosis <80% by duplex ultrasound (20.6%), suspected brachiocephalic trunk stenosis (15.8%), unclear anatomy by duplex (10.3%), recurrent carotid stenosis (10.3%), symptomatic high-grade (>80% by duplex) internal carotid stenosis (9.8%), ipsilateral internal carotid artery occlusion (7.1%), bilateral high-grade internal carotid artery stenoses (7.1%), vertebral-basilar ischemia (7.0%), contralateral internal carotid occlusion (5.4%), duplex ultrasound from a nonaccredited vascular laboratory (3.3%), and evaluation of nonatherosclerotic carotid disease (3.3%). There were no transient ischemic attacks, strokes, or deaths related to the index procedure. Selective angiography of the extracranial carotid arteries remains an important adjunct in the evaluation of patients with carotid disease. This procedure can be performed safely by vascular surgeons.

Has the emergence of endovascular treatment for aneurysmal and occlusive aortic disease increased the complexity and difficulty of open aortic operations?

With the emergence of endovascular surgery, there is a perception that open aortic procedures for aneurysmal and occlusive disease have become more difficult. To test this hypothesis, two consecutive groups of patients undergoing open aortic surgery for aneurysmal (AAA) and occlusive (AIOD) disease before and after the establishment of an endovascular program (EP) were analyzed. The pre-EP patient group (January 1996 through December 1997) consisted of 112 patients (52 with AAA, 60 with AIOD) and the post-EP patient group (January 2000 through December 2001) consisted of 142 patients (72 with AAA, 70 with AIOD). The pre-EP AAA group was compared with the post-EP AAA group and the pre-EP AIOD group was compared with the post-EP AIOD group. Factors analyzed included patient demographics, comorbidities, and operative outcomes. Statistical comparisons were carried out using Fisher's exact test for proportions and the Wilcoxon rank-sum test for medians. There were no statistical differences in patient demographics between the pre-EP and post-EP groups, regardless of procedure. When considering AAA repair, there was a higher rate of hypertension and hypercholesterolemia in the pre-EP group and a higher number of total comorbidities per patient in the post-EP group. There was also an increased incidence of perioperative blood transfusion in the post-EP group. When considering open procedures for AIOD, there was an increased rate of hypertension and history of previous abdominal operation in the post-EP group. There also was an increased incidence of perioperative blood transfusion. Other than these factors, there were no statistically significant differences between the pre- and post-EP groups with regard to mortality, complication rate, length of procedure, blood loss, length of ICU stay, or length of hospital stay for either the aneurysmal patients or the occlusive disease patients. With only minor exception, endovascular surgery has not appreciably increased the complexity of open aortic operations performed for either AAA or AIOD.