Endovascular AAA repair in a patient with a horseshoe kidney and an isthmus mass

PURPOSE

To report the endovascular exclusion of an abdominal aortic aneurysm (AAA) in a patient with a horseshoe kidney and an isthmus mass with preservation of accessory renal vessels.

CASE REPORT

A 70-year-old man with a 5-cm AAA and renal cell carcinoma involving a horseshoe kidney was treated with an AneuRx bifurcated graft. Two accessory renal arteries believed to feed the isthmus mass were sacrificed, but 2 other accessory renal arteries from the left common iliac artery (CIA) were preserved by using an extension cuff to cover the aneurysmal left CIA distal to their origins. The right renal isthmus mass decreased in size on follow-up imaging. At 9 months, there was no endoleak evident on computed tomographic scans, and the aneurysm measured 4.8 cm.

CONCLUSIONS

The presence of accessory renal arteries in AAA patients with horseshoe kidneys should not automatically exclude them from consideration for endovascular repair. Creative stent-graft arrangements can be a treatment option.

Lower extremity bypass graft revision in diabetics

Revision of lower extremity bypass graft stenoses identified by surveillance duplex scanning is frequently required in diabetic patients. The authors evaluated (1) the value of routine angiography before graft revision in diabetics, (2) factors that predict patients in whom angiography alters management, and (3) the incidence of recurrent stenosis and factors that might predict it. Forty-two infrainguinal primary vein bypasses undergoing primary revision were retrospectively studied. The initial graft stenosis was detected at a mean of 11.5 +/-3.6 months after the original bypass. Angiograms were obtained in 38 cases, revealing additional findings in 29 of 38 cases (76%), with a resultant alteration of the operative plan in 27 cases (71%). The most frequent additional angiographic finding was the identification or localization of a lesion in the inflow or outflow tracts (18 of 27 cases). Cases where the angiogram altered the management plan had a mean systolic velocity ratio across the stenosis (Vr) of 7.3 +/-6.1, versus a Vr of 4.8 +/-1.3 for cases where the angiogram did not alter the management plan (p<0.04). Duplex scanning identified 4 lesions that were not seen on angiography; 3 of 4 were confirmed as webs at surgery. Twenty of 42 grafts (48%) developed recurrent stenoses at a mean of 4.9 +/-3.8 months from initial revision. Restenosis occurred in 69% of female limbs as compared to 38% of male limbs (p=0.06). Recurrent stenosis was not a predictor of ultimate graft failure, unless left untreated. Four of 10 untreated grafts ultimately failed. A total of 9 of the 42 grafts eventually failed (21%), leading to 3 amputations (7%). The authors conclude that failing infrainguinal bypass grafts identified by duplex in diabetics should undergo a detailed angiographic evaluation. This frequently leads to an alteration in the management plan, especially in the presence of a high Vr across stenoses. High rates of limb salvage (93%) and assisted primary graft patency (79%) despite a high recurrent stenoses rate (48%) justify routine duplex surveillance, preoperative angiography, and aggressive graft revision in diabetic patients with infrainguinal grafts.

Changing patterns of access site complications with the use of percutaneous closure devices

The authors report their experience with 15 cases of groin complications associated with the use of percutaneous closure devices following femoral arterial catheterization over a 2-year period. The complication rate was 1.7% for catheterizations in which a closure device was used. The 15 cases included 7 uncomplicated pseudoaneurysms (PSA), 3 infected pseudoaneurysms, 4 nonarterial groin infections (infected hematomas and/or abscesses), and 1 case of femoral artery occlusion. These complications presented at an average of 5 +/- 4 days postcatheterization. One patient with an infected PSA required a below-the-knee amputation. During the same time interval, there were no infectious complications in patients not receiving closure devices. We conclude that groin complications associated with such devices tend to present late and include a higher percentage of infections as opposed to complications occurring in patients not receiving closure devices. An aggressive surgical approach to these problems appears warranted.

Autologous superficial femoral vein for the repair of suprarenal mycotic aneurysms: a preferred conduit?--a case report

The authors report a patient who presented with a ruptured mycotic aneurysm that destroyed the posterior segment of the suprarenal perimesenteric aorta. Initial in-line repair with a rifampin-soaked Dacron prosthetic patch failed 14 days postoperatively with recurrent hemorrhage. At reoperation, the aorta was repaired with a superficial femoral/popliteal vein interposition graft; a segment of superficial femoral/popliteal vein was also used in-line to revascularize the superior mesenteric and celiac arteries. The patient survived with no evidence of recurrence at 8 months postoperatively.

Noninvasive localization of infrainguinal arterial occlusive disease in diabetics

A retrospective review of 101 diabetics without aortoiliac disease was carried out to analyze the ability of various noninvasive tests to predict the level of significant (>50% stenosis) infrainguinal arterial disease. Patients were studied with anklebrachial indices (ABI), toebrachial indices (TBI), segmental pulse volume recordings (PVR), segmental pressures (SEGP), segmental Doppler waveforms (DWF), and arteriography. Results were classified as normal, disease at the femoropopliteal level, infrapopliteal level, or both levels (multilevel), or noninterpretable. Our findings for the entire study showed that, as a single test, DWF appears to have the best angiographic correlation, although the summed diagnosis of combined DWF and PVR data is superior in distinguishing multilevel disease from isolated tibial disease. SEGP are of very limited use in diabetics, even in multimodality testing, and we no longer include that test in our routine evaluation of diabetics.

Efficacy of infrainguinal bypass for limb salvage in young diabetic patients

The efficacy of infrainguinal bypass for limb salvage in young diabetic patients has not been well established. The purpose of this study is to determine the intermediate-term results (patency and limb salvage) of infrainguinal revascularization carried out for limb salvage (rest pain or ulceration) in young (<50 years old) diabetic atherosclerotic patients. Thirty-nine bypasses in 31 patients with a mean age of 44 years were retrospectively reviewed. There were no perioperative deaths. Minor or major complications occurred in 23% of cases. By life table analysis, the 18-month primary patency rate was 60+/-11%, assisted primary patency rate was 78+/-9%, and limb salvage rate was 71+/-9%. Most major amputations (five of nine) were required in patients with functional bypasses, either because of persistent infection or failure of wound healing. The presence of severe stenoses (>70%) in all three major named foot vessels (dorsalis pedis, medial and lateral plantar arteries) was associated with a high likelihood of limb loss despite a patent bypass (p<0.05). We could not identify any other factors statistically predictive of thrombosis, amputation, or the need for graft revision. Infrainguinal revascularization in this patient population can be carried out with acceptable limb salvage rates. However, patients should be made aware of the high incidence of amputation regardless of the success of the revascularization procedure, particularly in the presence of severe occlusive disease within the foot.

Primary aortoduodenal fistula and Q fever: an underrecognized association?

We report a rare case of primary aortoduodenal fistula (ADF) secondary to a Coxiella burnetii (Q fever) infection in a patient with an abdominal aortic aneurysm. A review of the available literature on the vascular complications of Q fever is presented. Q fever should be suspected in vascular patients with close animal contact when a standard infectious work-up is unrevealing. Diagnostic steps and management strategies for primary ADF are also briefly reviewed.

Global biodiversity scenarios for the year 2100

Scenarios of changes in biodiversity for the year 2100 can now be developed based on scenarios of changes in atmospheric carbon dioxide, climate, vegetation, and land use and the known sensitivity of biodiversity to these changes. This study identified a ranking of the importance of drivers of change, a ranking of the biomes with respect to expected changes, and the major sources of uncertainties. For terrestrial ecosystems, land-use change probably will have the largest effect, followed by climate change, nitrogen deposition, biotic exchange, and elevated carbon dioxide concentration. For freshwater ecosystems, biotic exchange is much more important. Mediterranean climate and grassland ecosystems likely will experience the greatest proportional change in biodiversity because of the substantial influence of all drivers of biodiversity change. Northern temperate ecosystems are estimated to experience the least biodiversity change because major land-use change has already occurred. Plausible changes in biodiversity in other biomes depend on interactions among the causes of biodiversity change. These interactions represent one of the largest uncertainties in projections of future biodiversity change.

Global biodiversity scenarios for the year 2100

Scenarios of changes in biodiversity for the year 2100 can now be developed based on scenarios of changes in atmospheric carbon dioxide, climate, vegetation, and land use and the known sensitivity of biodiversity to these changes. This study identified a ranking of the importance of drivers of change, a ranking of the biomes with respect to expected changes, and the major sources of uncertainties. For terrestrial ecosystems, land-use change probably will have the largest effect, followed by climate change, nitrogen deposition, biotic exchange, and elevated carbon dioxide concentration. For freshwater ecosystems, biotic exchange is much more important. Mediterranean climate and grassland ecosystems likely will experience the greatest proportional change in biodiversity because of the substantial influence of all drivers of biodiversity change. Northern temperate ecosystems are estimated to experience the least biodiversity change because major land-use change has already occurred. Plausible changes in biodiversity in other biomes depend on interactions among the causes of biodiversity change. These interactions represent one of the largest uncertainties in projections of future biodiversity change.

Vascular evaluation of the problem diabetic foot

Ischemia plays a pivotal role in the management of the problem diabetic foot. Prompt revascularization offers the patient with diabetes with lower-extremity ischemia the best hope for limb salvage and normal ambulation. The true vascular status of the diabetic foot may be difficult to assess by clinical examination. Because of the dangers of missing correctable vascular disease, noninvasive vascular testing plays an important role in the evaluation of the problem diabetic foot. The laboratory should have documented reliability, and its results must be interpreted in the context of the patient's clinical progress. The most common laboratory error is overestimating the blood supply to the foot because of technical problems with mural calcification. Algorithms for the use of the vascular laboratory for common foot problems are presented. The vascular laboratory, although helpful, is no substitute for clinical judgement. When ischemia is suspected or when response to conservative care is poor, early vascular surgical consultation is prudent.

Determining outcomes of a lower extremity vascular reconstruction program

Demonstrating positive outcomes after surgical intervention is an important aspect for the patient and payor in today's health care setting. A lower extremity arterial reconstruction program was established and has shown a decrease in length of stay. Additional long-term outcome measures related to graft patency surveillance, readmission rate and related cause, and functional health status are being implemented.

Dual-inflow great vessel aneurysm: delayed presentation after penetrating trauma

Aneurysms constitute uncommon sequelae of injuries to the thoracic outlet. Most such aneurysms are secondary to blunt trauma and usually involve the great vessels at their take-off from the aortic arch. Penetrating injuries are more often identified in the more distal vessels and only very rarely present as pseudoaneurysms. Reported here is a single case of a chronic posttraumatic pseudoaneurysm arising from both the right common carotid artery and the right subclavian artery. The workup and surgical approach provide practical lessons, complemented with illustrations that aid in the understanding of the case. It is an unusual case because of the dual-inflow nature of the aneurysm.

The functional ecology of Empodisma minus (Hook, f.) Johnson & Cutler in New Zealand ombrotrophic mires

Mires dominated by restionaceous rushes occur in valley and basin sites around New Zealand. The main restiad species is Empodisma minus which produces a surface mat of negative geotropic roots which eventually form a principal part of the underlying peat. Comparison of the peat chemistry of four such mires with a minerotrophic mire w*as consistent with their suspected ombrotrophic status. The base-exchange capacity achieved (704 + 23.3 mequiv m^-2 of the surface) by the superficial roots of Empodisma is at least as great as that of the New Zealand Sphagnum cristatum which is not dominant in ombrotrophic conditions. The widespread development of a hummock and hollow microtopography may be associated with higher rainfall regimes and the propensity of Empodisma for directing most incoming rainfall (on which its nutrient economy depends) down its wiry stems.

Unmyelinated axons in human ventral roots, a possible explanation for the failure of dorsal rhizotomy to relieve pain

Human ventral roots were examined in the light and electron microscopes. The noteworthy finding is that all roots contain large numbers of unmyelinated axons, and that they make up 27 per cent of the total population of ventral root axons. The function of these unmyelinated axons is not known, but for various reasons it is probable that a significant number are sensory. If so these axons might explain the failure of dorsal rhizotomy to relieve pain, and dorsal root gangionectomy, which would remove both dorsal and ventral root afferents, might be the procedure of choice for those patients where rhizotomy is contemplated.