A modified approach of proximalization of arterial inflow technique for hand ischemia in patients with matured basilic and cephalic veins.

OBJECTIVE: Proximalization of arteriovenous inflow (PAI) is an established technique for treating patients with access-induced hand ischemia. However, a prosthetic graft, used as arterial inflow, could minimize the benefits of a purely native fistula. In this study, a new PAI technique is reported, which avoids the use of prosthetic grafts in patients with matured basilic and cephalic veins. PATIENTS AND METHODS: Eight patients (seven men, one woman; mean age 62 (45-82) years old) with grade III/IV critical dialysis access-related ischemia (DARI) and with a pre-existing Gracz fistula underwent an operation using modified PAI. The basilic and cephalic veins were preoperatively matured. During the operation, the former arteriovenous anastomosis was closed and the basilic vein was used as arterial inflow. RESULTS: All procedures were technically successful. All patients but one could be discharged with a warm, neurologically improved extremity with a significant reduction in pain. After a mean follow-up of 43.5 (0-52) months, there were no recurrent steal symptoms and all necrotic hand lesions healed. Two patients died during the follow-up, but with well-functioning fistulae. One fistula failed during follow-up and one further fistula was ligated because of chronic neurological damage, which was not improved after the PAI procedure. Four AVFs are still available for hemodialysis. CONCLUSIONS: The modification of the PAI technique with a basilic vein as presented here showed similar results to the original PAI procedure. This new procedure does not require prosthetic grafts as in the original PAI technique or a central venous catheter and leads to the enlargement of the puncture site as a result of the superficialization of the basilic vein. Therefore, it is believed that this new technique could be a good option for those patients with matured cephalic and basilic veins who suffer from severe access-related ischemia.

Endovascular repair of acute uncomplicated aortic type B dissection promotes aortic remodelling: 1 year results of the ADSORB trial.

OBJECTIVES: Uncomplicated acute type B aortic dissection (AD) treated conservatively has a 10% 30-day mortality and up to 25% need intervention within 4 years. In complicated AD, stent grafts have been encouraging. The aim of the present prospective randomised trial was to compare best medical treatment (BMT) with BMT and Gore TAG stent graft in patients with uncomplicated AD. The primary endpoint was a combination of incomplete/no false lumen thrombosis, aortic dilatation, or aortic rupture at 1 year. METHODS: The AD history had to be less than 14 days, and exclusion criteria were rupture, impending rupture, malperfusion. Of the 61 patients randomised, 80% were DeBakey type IIIB. RESULTS: Thirty-one patients were randomised to the BMT group and 30 to the BMT+TAG group. Mean age was 63 years for both groups. The left subclavian artery was completely covered in 47% and in part in 17% of the cases. During the first 30 days, no deaths occurred in either group, but there were three crossovers from the BMT to the BMT+TAG group, all due to progression of disease within 1 week. There were two withdrawals from the BMT+TAG group. At the 1-year follow up there had been another two failures in the BMT group: one malperfusion and one aneurysm formation (p = .056 for all). One death occurred in the BMT+TAG group. For the overall endpoint BMT+TAG was significantly different from BMT only (p < .001). Incomplete false lumen thrombosis, was found in 13 (43%) of the TAG+BMT group and 30 (97%) of the BMT group (p < .001). The false lumen reduced in size in the BMT+TAG group (p < .001) whereas in the BMT group it increased. The true lumen increased in the BMT+TAG (p < .001) whereas in the BMT group it remained unchanged. The overall transverse diameter was the same at the beginning and after 1 year in the BMT group (42.1 mm), but in the BMT+TAG it decreased (38.8 mm; p = .062). CONCLUSIONS: Uncomplicated AD can be safely treated with the Gore TAG device. Remodelling with thrombosis of the false lumen and reduction of its diameter is induced by the stent graft, but long term results are needed.

Occlusion of arteriovenous fistulas of in-situ saphenous vein bypass grafts using the amplatzer vascular plug 4: initial experience.

We examined the safety and efficacy of vessel occlusion of the Amplatzer Vascular Plug 4 (AVP-4) in patients with arteriovenous fistulas after in-situ saphenous vein bypass grafts. We treated 18 fistulas of seven patients (four women, mean±standard deviation age 76±7 years, range 63-88 years). All fistulas were detected within 14 days after surgery. Initial diagnosis and follow-up was established by sonography. We measured the diameter of the feeding vessel and the time of vessel occlusion after plug deployment. Additionally, we recorded procedure time and the dose area product. Additional interventional procedures were necessary in three patients. We successfully used 19 AVP-4 for occlusion of all fistulas without thromboembolic complications. There was no need for recapturing the device, and we did not observe dislocation. Mean occlusion time was 9.6 min (range 5-22 min). Mean diameter of the feeding vessels was 3.5 mm (range 2.6-5.1 mm). Plug sizes ranged from 4-8 mm (mean 5.5 mm) resulting in an oversizing of 33-88%. Mean procedure time for patients with and without additional intervention was 91±38 min and 35±18 min, respectively. Mean dose area product was 11,790 cGy/cm2 (range 1,850-23,500 cGy/cm2). Permanent occlusion of the fistulas was confirmed by ultrasound after a mean follow-up of 4 months (1-6 months). Occlusion of arteriovenous fistulas with an AVP-4 seems to be effective and safe in patients with in-situ saphenous vein bypass grafts. The AVP-4 is well suited for this purpose because of the appropriate diameter of the feeding vessels.

Evidence that statins protect renal function during endovascular repair of AAAs.

OBJECTIVES: Several studies have documented a slight but significant deterioration of renal function after endovascular repair of abdominal aortic aneurysm (AAA) (EVAR). The aim of this retrospective study was therefore to investigate whether medication with statins may favourably affect perioperative renal function. MATERIAL AND METHODS: From January 2000 to January 2008, out of a total cohort of 287 elective patients receiving endovascular repair of their AAA or aortoiliac aneurysm, 127 patients were included in the present study, as their medication was reliably retrievable. Patients were divided according to whether their medication included statins (>3 months). Second, they were subdivided according to their supra- (SR) or infrarenal (IR) endograft fixation. Serum creatinine (SCr) and creatinine (CrCl) clearance were determined preoperatively, postoperatively, at 6 and 12 months. Patients with known pre-existing renal disease, with incorrect placement of the stent graft resulting in severe renal artery stenosis, and with occlusion or renal parenchymal infarction were excluded from the study. RESULTS: Patients receiving an infrarenal fixation of their graft had no change in the renal function, regardless whether they were on statins or not. In patients with SR fixation not receiving statins, a deterioration in renal function was observed in the early postoperative period ((SCr) preoperative vs. SCr postoperative: 1.02±0.2 vs. 1.11±0.28, p<0.001 and (Cr.Cl) preoperative vs. Cr.Cl postoperative: 74.1±21.4 vs. 68.0±21.4, p<0.001), whereas patients on statins experienced no change in renal function (SCr preoperative vs. SCr postoperative: 0.99±0.24 vs. 1.02±0.20n.s. and Cr.Cl preop vs. Cr.Clpostop.: 76.4±19.1 vs. 74.28±20.50, n.s.). During follow-up, a constant worsening of renal function at 6 and 12 months was observed, irrespective of the medication with statins. CONCLUSIONS: The present study suggests a slight immediate deterioration of the renal function using (SR) fixation, and this could be prevented by the use of statins. During follow-up, statins did not protect from further renal deterioration. Broader studies are needed to confirm a definitive relation between statin use and renal protection during the endovascular repair of AAA.

Primary extraanatomical revascularization for groin infections in drug addicts.

BACKGROUND: Arterial groin infections in drug addicts are associated with a risk of amputation and are potentially lethal. Primary revascularization with an obturator bypass represents a potential alternative to local revision and arterial ligation alone. We report our experience with this approach. PATIENTS AND METHODS: From January 1999 until December 2005 twelve drug addicts were treated due to arterial infections in the groin. In eight patients (seven men, one woman, 31 years old on average), the defect in the artery could not be repaired and ligation of the femoral vessels led to critical ischemia. Therefore, an iliaco-popliteal bypass via the foramen obturatorium was implanted either primarily or secondarily. In three patients a cryopreserved homologous vein was used, five patients received alloplastic grafts. RESULTS: Four of eight obturator bypasses were implanted primarily. In the other four patients the initial treatment was limited to local debridement and artery ligation and an obturator bypass was implanted at a later date. Two grafts occluded within the first 30 days. Thereof one was successful thrombectomized. The other patient had no critical ischemia and he refused further surgery. Three more grafts occluded at 74, 90 and 103 days after surgery. No patient demonstrated signs of graft infection and all groin incisions healed uneventfully. A lower limb amputation became necessary in one patient even though the reconstruction was patent due to embolisation of mycotic material. All patients remained drug dependent throughout the followup time which was 3 months on average and ranged from one to 40 months. CONCLUSIONS: The patency of obturator bypasses was 75% at one month. This appears low, especially if one considers the youthful age of the patients and the absence of arterial occlusive disease. Nevertheless, the amputation rate also remained low. Therefore, we feel that this technique may contribute to limb salvage in groin infections in drug addicts.

Primary stroke unit treatment followed by very early carotid endarterectomy for carotid artery stenosis after acute stroke.

BACKGROUND: Although it is recognized that carotid endarterectomy (CEA) is the treatment of choice in symptomatic internal carotid artery (ICA) stenosis, in the past, very early CEA has been shown to carry substantial risks. We assessed an interdisciplinary concept of very early CEA in patients with high-grade (>70%) symptomatic ICA stenosis at a single center. PATIENTS AND METHODS: The course of treatment and outcomes of patients who underwent CEA as early as possible after being referred to the stroke unit for symptoms of transient ischemic attack and stroke were prospectively evaluated, including the following parameters: age, severity of ischemia-related symptoms according to the modified Rankin scale, duration of symptoms until admission, multimodal imaging findings (color-coded duplex, cranial computed tomography, magnetic resonance imaging, positron emission tomography), duration until CEA, perioperative course and complications, as well as duration of in-hospital care. RESULTS: Fifty consecutive patients (median age 68 years, range 44-90) with clinical and imaging signs of transient ischemic attack (n = 19) or stroke (n = 31) were included from January 2000 until December 2004. All except 1 patient showed a preoperative Rankin < 4. There was a median time period of 6 h between the onset of symptoms and admission (range 1 h to 15 days) and a median duration of 4 days after admission until operation (range 1-21 days). Seven patients underwent CEA of the contralateral, severely stenosed ICA after symptomatic ipsilateral ICA occlusion. Four out of 5 patients who primarily underwent systemic thrombolysis recovered almost completely. Three patients (6%) experienced a clinical deterioration before surgery. In the majority of patients (43/50), CEA was performed under local anesthesia with selective shunt use which became necessary in 26%. Three patients (6%) had postoperative worsening due to new infarcts. In 2 cases, an intracerebral hemorrhage occurred, of which 1 remained asymptomatic. In 1 case, surgical revision was necessary because of an ICA thrombosis without permanent neurological decline. Patients were discharged after a median time of 14.5 days (range 4-44). CONCLUSIONS: After careful selection and preparation in a stroke unit, patients with acute stroke due to carotid stenosis can undergo very early CEA under local anesthesia with a perioperative risk comparable with the risk of later endarterectomy, therefore preventing very early stroke recurrences.

Changes in internal carotid blood flow after CEA evaluated by transit-time flowmeter.

AIM: The aim of this study was to investigate whether there was an association between the degree of the stenosis of the internal carotid artery (ICA) and post-operative increase of blood flow. METHODS AND MATERIALS: In 200 out of 660 patients undergoing carotid endarteriectomy (CEA) for a high-degree ICA stenosis, pre-operatively a bilateral selective carotid and intracerebral angiography was performed. The degree of the ipsilateral and contralateral stenosis was digitally assessed by using computer software according to the CC-Index. Intraoperatively, the pressure ratio over the stenosis (ICA/CCA) was measured by direct arterial puncture. Blood flow in the ICA was measured before and after CEA with an ultrasound flowmeter using the transit-time principle. These findings were correlated to the degree of stenosis revealed by angiographic analysis and the pressure ratio. RESULTS: Before CEA the median blood flow in the ICA was 171 ml/min (range 620 ml/min) with a significant (p<0.001) post-operative increase to 250 ml/min (range 875 ml/min). The median relative increase of flow (post-flow-pre-flow/pre-flow) was 42%. The pre-CEA flow volumes were dependent on the degree of stenosis and also the pressure ratio. The increase of flow following CEA correlated better with pressure ratio (r=-0.435, p<0.001), than the stenosis severity (r=0.319, p<0.001). Analysis of variance identified only the pressure gradient as an independent determinant of flow changes following CEA. CONCLUSIONS: The blood flow increase following CEA is mainly determined by the pressure gradient across the stenosis.

Prediction of cerebral ischemic tolerance during carotid cross-clamping by angiographic criteria.

OBJECTIVE: To evaluate the prognostic value of angiographic criteria and internal carotid artery (ICA) stump pressure for shunt placement in carotid surgery under local anaesthesia. DESIGN: Prospective clinical trial at a university hospital. MATERIALS AND METHODS: In 120 patients a cerebral angiography was initiated before undergoing carotid surgery. Seventy-five percent of the patients were neurologically asymptomatic, 13% had transient ischaemic attacks and 12% suffered from previous strokes. The operation was exclusively performed under local anaesthesia and prior to cross-clamping the ICA stump-pressure was measured. A shunt was inserted only if hemispheric symptoms or unconsciousness occurred independent of the angiographic findings or stump pressure. RESULTS: In 23% (27/120) a shunt became necessary and significantly (p<0.001) more often when there was a cross-flow towards the contralateral hemisphere (12/20=60%) or if the contralateral ICA was occluded (9/13=69%). The sensitivity for not needing a shunt in case of cross-flow towards the side of operation was 91% (52/57) whereas the specificity was 35% (22/63). ICA stump-pressure was significantly reduced in patients requiring a shunt (31 mmHg) compared to those not needing a shunt (53 mmHg) (p<0.001), but no definitive threshold value was found determining the need for shunting. Intraoperatively, no persistent neurological complication developed. CONCLUSIONS: Angiographic cross-flow was a good, but not perfect predictor for the need of an intraoperative shunt.