[Varicosis-Current treatment concepts]. / Varikosis ­ aktuelle Therapiekonzepte.

Varicosis is a chronic progressive disease characterized by varicose veins of the lower extremities. Pain, swelling and heaviness of the legs are typical symptoms. These symptoms are caused by a pathological venous reflux, arising from a weakness of the vein wall and progressive venous insufficiency. The indications for invasive surgery are the symptomatic clinical, etiological, anatomical, pathophysiological (CEAP) stages C2s-C6. Compression therapy and venoactive drugs can be recommended for conservative therapy. When it comes to surgical treatment conventional open vein surgery is associated with the best long-term results. Endovenous thermal ablation is associated with few postoperative complications and favors earlier mobilization of the patient. Sclerotherapy has become established with good clinical results for the ablation of reticular and telangiectatic veins, for recurrences and complicated vein anatomy.

Novel chimney-graft technique for preserving hypogastric flow in complex aortoiliac aneurysms.

We describe the feasibility and result of a novel approach to preserve pelvic perfusion during endovascular aortoiliac aneurysm repair (EVAR) in patients with aortoiliac aneurysms extending to the iliac bifurcation. The iliac chimney-graft technique consists of the deployment of a ViaBahn™ graft into the hypogastric artery in combination with standard abdominal aortic stent-grafts. The chimney graft was deployed using a transsubclavian access and placed parallel with the iliac limb into the standard aortic stent graft, which was deployed directly before. The technical procedure was successful. Postoperative control showed a sufficiently excluded aneurysm without evidence of endoleak and good distal perfusion of both iliac arteries. The CT-scan after 6 months confirmed the result. The chimney-graft stent grafts to maintain perfusion to hypogastric arteries are feasible and provide an alternative to hypogastric artery exclusion or branched grafts. Long-term follow-up is needed to evaluate stent-graft patency and failure rates.

Novel chimney-graft technique for preserving hypogastric flow in complex aortoiliac aneurysms.

We describe the feasibility and result of a novel approach to preserve pelvic perfusion during endovascular aortoiliac aneurysm repair (EVAR) in patients with aortoiliac aneurysms extending to the iliac bifurcation. The iliac chimney-graft technique consists of the deployment of a ViaBahn™ graft into the hypogastric artery in combination with standard abdominal aortic stent-grafts. The chimney graft was deployed using a transsubclavian access and placed parallel with the iliac limb into the standard aortic stent graft, which was deployed directly before. The technical procedure was successful. Postoperative control showed a sufficiently excluded aneurysm without evidence of endoleak and good distal perfusion of both iliac arteries. The CT-scan after 6 months confirmed the result. The chimney-graft stent grafts to maintain perfusion to hypogastric arteries are feasible and provide an alternative to hypogastric artery exclusion or branched grafts. Long-term follow-up is needed to evaluate stent-graft patency and failure rates.

[The role of intra-operative Prostavasin application during crural bypass surgery]. / Der Effekt der intraoperativen Prostavasingabe bei kruraler Bypasschirurgie.

INTRODUCTION: The aim of this study was to evaluate the role of intra-operative Prostavasin application during crural bypass surgery. 68 Patients, who underwent infrainguinal autologous vein bypass surgery, were prospectively analyzed. RESULTS: Intra-operative flow measurements and Prostavasin administration were performed in all patients. The mean flow was 105 ml / min (minimal flow 18 ml / min, maximal flow 321 ml / min). The means of maximal and minimal flow were 329 und 30 ml / min, respectively. The mean of the calculated Pulsatility index was 3.1. The mean flow volume increased after administration of Prostavasin in all patients with a mean increase of 103 %. The Pulsatility index decreased by 39 %. Primary and secondary patency rates after 1 year were 70.3 % und 73.1 %, respectively. The differentiated analyses of the region of the distal anastomoses (popliteal / crural) showed a statistically significant bigger increase of Q after Prostavasin application for infrainguinal popliteal bypasses compared to patients with crural reconstructions (p = 0.05). In addition, the decrease of the Pulsatility index was significantly higher in popliteal grafts (p = 0.03). Patients with early bypass graft failure showed a significantly smaller decrease of PI after Prostavasin application compared to the other patients. CONCLUSION: The profit of intra-operative arterial Prostavasin application is first of all an immediate one. The injection of Prostavasin leads to an instant vessel dilatation. This allows the surgeon to get an impression of the flow capacity of the bypass. The Pulsatility index as an indicator for resistance is an important factor for bypass patency.

Immediate CEA for symptomatic carotid disease preferably performed under local anaesthesia is safe.

BACKGROUND: Previous general reservations against carotid endarterectomy (CEA) early after stroke, which were primarily based on concerns of postoperative intracerebral hemorrhage, are resolved. Moreover, a delay of surgery is proofed to be associated with a risk of recurrent cerebral ischemia. However, the complication rate of CEA seems to increase with less time interval to the onset of symptoms. The main purpose of this study was to assess the safety of very early CEA. PATIENTS AND METHODS: Patients having a symptomatic high-grade (> 70%) internal carotid artery (ICA) stenosis were referred by neurologists for CEA within different timeframes, so that they were later differentiated depending on whether surgery was performed within 2 days (immediate CEA = iCEA) or 2 weeks (urgent CEA = uCEA) after neurological deficits have occurred primarily. The perioperative complication rate in these groups was than evaluated and compared. RESULTS: From January 2000 until August 2006 130 consecutive patients (median age 68 years, range: 42-90; 66% male, 34%female)presenting with an ipsilateral TIA (n = 80), stroke (n = 50) underwent iCEA (n = 40) or uCEA (n = 90). Demographic and clinical characteristics were equally distributed between treatment groups. Mostly (121/130), CEA was performed under local anaesthesia with selective shunt use which became necessary in 26%. Besides postoperative hemorrhage (n = 4), cardiac complications (n = 2) and temporary cranial nerve lesions (n = 2), new perioperative neurological deficits occurred in total in 8 patients of which 6 were temporary. The other 2 patients developed strokes of which one patient died. Therefore, the combined stroke- and mortality rate was 1.5% (2/130) for the whole study population. With regard to the timing of surgery, a single incident was observed after iCEA (1/40) which also was the only intracerebral hemorrhage. CONCLUSIONS: It seems that patients with a symptomatic high-grade ICA stenosis can undergo CEA particularly under local anaesthesia as soon as possible without anticipating an increased complication rate.

Combined endovascular-open surgical procedure in a great hepatic artery aneurysm.

Visceral artery aneurysms are rare lesions. They involve the hepatic artery in approximately 20% of cases. Various therapeutic options are available for patients with hepatic artery aneurysms (HAAs). Dictated predominately by the need to maintain distal end-organ perfusion, potential therapies include traditional surgical techniques and laparoscopic surgery, endovascular methods of embolization, and stenting of the lesions. There is still a lack of studies demonstrating the comparative efficacy or inefficacy of any particular treatment, so there are currently no precise indications for determining which type of treatment should be used. In this paper, we present a case of great HAA in a 59-year-old man. He was preoperatively diagnosed and treated with a combined surgical and endovascular approach. The clinical presentation, management, and therapy of patients with HAAs are discussed. In addition to that, we reviewed the literature dealing with HAAs. This case report lays emphasis on the aspect that the treatment strategy in HAAs has to be determined individually in each case due to the high anatomic variability of the arterial supply of the liver. Treatment with a combined surgical and endovascular approach may reduce the risk of liver ischemia and morbidity.

Evaluation of changes of systemic blood pressure and shunt incidence in CEA.

BACKGROUND: Induced hypertension is widely recommended as a protective measure in carotid endarterectomy (CEA) to prevent shunt insertion. In this study changes of systemic blood pressure were evaluated in relation to the shunt rate when CEA was performed under local anaesthesia. MATERIALS AND METHODS: In 930 CEAs performed for a high-grade (>70%) ICA stenosis under local anaesthesia the mean systemic blood pressure was measured preoperatively (RR1) and directly before carotid cross-clamping (RR2). A ratio was calculated from these values (RRR=RR2/RR1). A shunt was only inserted for clinical signs of cerebral ischemia. If that became necessary later after cross-clamping had been tolerated primarily, the blood pressure during this period was also recorded (RR3). Also the presence of a contralateral ICA occlusion and baseline blood pressure levels were considered as factors with potential impact on shunt necessity. RESULTS: Among the 638 male (69%) and 292 female (31%) patients with a median age of 70 years (ranging from 52 to 91 years) 82 (9%) had a contralateral ICA occlusion. A shunt was used in 177 operations (19%) and significantly more frequent in patients with a contralateral ICA occlusion (39/82=48% vs. 138/848=16%, p<0,001). RRR was significantly reduced in patients who needed a shunt (0.95 (0.41-1.53) vs. 1.0 (0.54-1.9), p=0.002) which was only true for patients with a patent contralateral ICA. The shunt rate did not differ when contrasting RRR thresholds (<0.7 vs. >1.3) or preoperative blood pressure levels (<100 mmHg vs. >120 mmHg) were compared. RRR did not differ between directly or delayed shunted patients. RR3 did not differ significantly from RR2. A regression analysis identified the presence of a contralateral ICA occlusion as the only independent parameter influencing shunt insertion. CONCLUSIONS: Changes in systemic blood pressure during CEA under local anaesthesia seem to influence shunting rather marginally. The value of induced hypertension to prevent cerebral ischemia should be newly discussed.

Photodynamic therapy reduces intimal hyperplasia in prosthetic vascular bypass grafts in a pig model.

BACKGROUND: Bypass surgery has a failing frequency of 30% during the first year, mainly due to intimal hyperplasia (IH). This negative effect is most pronounced in artificial grafts. Photodynamic therapy (PDT) is a technique in which light activates photosensitizer dyes to produce free-radicals resulting in an eradication of cells in the vascular wall. The aim of this study was to determine the effectiveness of PDT to reduce IH in a preclinical porcine PTFE bypass model. MATERIAL AND METHODS: Ten pigs were used. After a pilot PDT dosimetry study (n=3) PTFE grafts were bilaterally placed into the circulation as bypasses from the common to the external iliac arteries (n=7). The right sides served as controls (C). Before implantation of the left grafts, the arterial connecting sites of the left distal anastomoses were PDT-treated. The arteries were pressurized at 180 mmHg for 5 minutes with the photosensitizer Methylene Blue (330 microg/ml), and thereafter endoluminally irradiated with laser light (lambda = 660 nm, 100 mW/cm(2), 150 J/cm(2)). After 4 weeks the specimens were retrieved and formalin fixed. Cross sections through the midportions of the distal anastomoses and the grafts were used for histology, immunohistochemistry to identify inflammatory cells and morphometric evaluation (n=7). RESULTS: No systemic side effects and no graft occlusions were noted. PDT-treated anastomoses showed reduced IH in the mid-portions of the anastomoses (Area of IH: microm(2)/microm graft: C: 6970+/-1536, PDT: 2734+/-2560; P<0.005) as well as in the grafts (C: 5391+/-4031, PDT: 777+/-1331; P<0.02). The number of inflammatory cells per microscopic field was increased after PDT (C: 24+/-16, PDT: 37+/-15; P<0.009). CONCLUSIONS: Adjuvant PDT, performed in an endovascular fashion, was a safe method to reduce prosthetic graftstenosis in a preclinical setting. This study underscores the clinical potential of PDT to inhibit the development of clinical bypass graftstenosis.

Endovascular treatment of a ruptured aneurysm of the inferior thyroid artery. Case report and literature review.

Aneurysms of the inferior thyroid artery are rare. The natural course of these aneurysms seems to be unfavourable, why aneurysm exclusion is recommended in the literature. Open surgical repair is complex why endovascular exclusion seems to be an appealing alternative. We present a patient who developed dysphagia and respiratory distress caused by a ruptured aneurysm of the right inferior thyroid artery. Successful coil embolization of the aneurysm is described along with a review of the literature. Despite the very rare data of these aneurysms, all reported cases of endovascular treatment (n=3) showed favourable results, therefore aneurysm embolization seems to be a feasible and safe alternative to open surgery, especially in emergency cases.

Hybrid-procedures for the treatment of thoracoabdominal aortic aneurysms and dissections.

AIM: The conventional open repair of thoracoabdominal aneurysms and dissections remains complex and demanding and is associated with significant morbidity and mortality. We present our experience of hybrid open and endovascular treatment of thoracoabdominal aneurysms and dissections. METHODS: Within an experience of 226 aortic stent-grafts between 1998 and April 2006, 6 of the patients (median age 60 years, range 35 to 68 years) with thoracoabdominal aneurysms (Crawford type I, II, III, and V) were treated with a combined endovascular and open surgical approach. Five men and one woman, with median aneurysm diameter of 75 mm (range 70-100 mm), received revascularization of the renal arteries, the superior mesenteric artery, and the coeliac trunk accomplished via transperitoneal bypass grafting. Aneurysmal exclusion was then performed by stent-graft deployment. RESULTS: The entire procedure was technically successful in all patients. The patients were discharged a median of 9 days after the operation, while the postoperative studies revealed the patency of the vessels and no evidence of type I endoleak or secondary rupture of the aneurysm. During follow up (1 to 22 months) spiral-CT scanning revealed distinct shrinkage of the aneurysm, no graft migration or endoleak and patency of all revascularised vessels, except one renal artery in two patients. No patient experienced any temporary or permanent neurological deficit, and no dialysis was necessary. CONCLUSION: The combined endovascular and open surgical approach is feasible, without cross clamping of the aorta and with minimized ischemia time for renal and visceral arteries, and seems to be an appropriate strategy for patients with a thoraco-abdominal aortic aneurysm or dissection.

Cognitive function remains unchanged after endarterectomy of unilateral internal carotid artery stenosis under local anaesthesia.

OBJECTIVE: To assess changes in cognitive function and affective state following carotid endarterectomy (CEA) for high-degree unilateral internal carotid artery stenosis. METHODS: In 33 patients, a CEA was performed under local anaesthesia for a high-grade unilateral stenosis of the internal carotid artery (group A). Twenty-five patients underwent surgery for peripheral arterial occlusive disease under regional anaesthesia served as controls (group B). Patients with neurological deficits due to previous strokes or dementia were excluded. Intelligence level was assessed preoperatively. Cognitive tests were applied preoperatively and postoperatively (3-5 days after surgery) and after 4 months follow-up. Confounding factors, including anxiety and depression, were checked through questionnaires and interviews. RESULTS: No perioperative neurological complication occurred following CEA. Patients in group A showed a significant postoperative deterioration only in one sub-test. There was no significant change in anxiety and depression during follow up. The control group B had no significant changes in cognitive test performance. Anxiety improved significantly postoperatively, but increased again at the end of the study. There was no significant difference between the groups over time. CONCLUSION: Cognitive function does not change following CEA of a unilateral internal carotid stenosis.

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.

Comparison of the prevalence of APC-resistance in vascular patients and in a normal population cohort in Western Germany.

OBJECTIVE: To compare the prevalence of APC-resistance (APC-R) in patients with peripheral vascular disease and the general population. DESIGN: Prospective cohort examination. MATERIALS AND METHODS: Three hundred and eleven patients (group A) suffering from arterial occlusive disease or an abdominal aortic aneurysm were prospectively screened for APC-R. There were 228 men and 83 women with a mean age of 65 years (20-88 years). Two hundred and sixty patients underwent an open surgical or interventional procedure. A total of 306 patients were followed clinically for an average of 8 months (1-31 months). Two hundred and seven healthy volunteers (group B) served as a control group. RESULTS: The prevalence of a functional APC-R was 11% (33/311) and 8% in groups A and B, respectively, (p = 0.272). APC-R did not occur more frequently among patients who were treated primarily for a bypass occlusion (3/21 vs 30/290) (p = 0.476). None of five patients who had a postinterventional graft or vessel occlusion (1.9%) had an APC-R. Sixteen patients (5%) experienced an arterial occlusion during follow-up of which two had APC-R. CONCLUSIONS: Previously published increased prevalence rates of APC-R in patients with arterial disorders could not be confirmed in this study. A firm association between the presence of APC-R and previous bypass occlusion or postoperative failure of the vascular reconstruction could not be demonstrated.

Radiation therapy induced modulation of wound healing at experimental vein graft anastomoses.

OBJECTIVES: The aim of this study was to investigate if radiation therapy (RT) favorably modulates wound healing at vein graft anastomoses. MATERIALS AND METHODS: Jugular vein grafts were sewn into carotid arteries in 32 rats which were randomly divided into two groups: RT (gamma source, 14 Gray, n=16) and control (C, sham irradiation, n=16). Grafts and adjacent arteries were analyzed at 2 (n=8) and 8 weeks (n=8) by histology, immunohistochemistry, and morphometry. RESULTS: Although, RT did not reduce the overall occurrence of intimal hyperplasia, the distribution differed. RT led to a reduction of intimal hyperplasia in arterial segments (median: C: 41.873 microm2; RT: 6.452 microm2, p < 0.0007). In contrast, RT augmented intimal hyperplasia in vein grafts (median: C: 30.287 microm2; RT: 90.455 microm2, p < 0.014). Vein graft diameters after RT were enlarged (median: C: 2.098 microm; RT: 3.381, p < 0.031). Over 80% of the cells were of mesenchymal origin in both groups. CONCLUSIONS: RT reduced intimal hyperplasia in arterial segments. However, RT led to graft dilatation and increased intimal hyperplasia in vein grafts. RT did not favorably modulate the vascular wound healing response in this model.

Differentiated treatment of aneurysms of the extracranial carotid artery.

AIM: Aim of the study is to illustrate current therapeutic options for aneurysms of the extracranial carotid artery. METHODS: From 1987 until 2003 14 patients (average age: 60 years) with an aneurysm of the extracranial internal carotid artery were treated. The aneurysm diameter ranged from 5 mm to 60 mm. Thirteen patients underwent elective surgery. One patient was operated upon because of acute severe cervical bleeding. RESULTS: Most patients (10/14) presented with an asymptomatic pulsatile cervical mass. The aneurysm was diagnosed 3 times during carotid angiography. The underlying etiology was atherosclerosis in 10 patients. In 3 cases the aneurysm was considered mycotic. Ten aneurysms were localized at the carotid bifurcation whereas 2 each were found in the retrostyloideal region and at the base of the skull. Vascular continuity could be restored in 10 patients while in 3 the carotid artery had to be occluded (twice surgically and once radiologically). The final patient underwent stent insertion for post-traumatic distal aneurysm. In 5 patients perioperative neurological complications were noted which persisted in a single patient (dysphagia due to a lesion of the hypoglossus nerve). All hemispheric complications recovered completely. During follow-up (median 48 months ranging from 3 to 103 months), 1 patient died of unrelated cause. Another patient developed a contralateral ischemic insult. CONCLUSIONS: When adjusting treatment to the various etiological conditions and localizations, aneurysms of the extracranial carotid artery can be managed with a low complication rate and satisfying long-term results. However, success mainly depends on the timely diagnosis and availability of a range of surgical and radiological therapeutical options.

Pulsatility index determination by flowmeter measurement: a new indicator for vascular resistance?

BACKGROUND: Peripheral resistance (R) is measured by flow (Q) and a pressure difference (P1-P2), where R equals (P1-P2)/Q. The pulsatility index (PI) has been used to assess peripheral vascular resistance by measuring flow velocities. Alternatively, PI can be expressed by the ratio of the flow volume amplitude and mean flow volume which both are quantified by a flowmeter. While reflected flow due to a distally located stenosis will considerably influence PI, this parameter theoretically could provide a good estimation of resistance. The appropriateness of this presumption has not been evaluated in this setting though, why the correlation of PI in flow recordings was examined by comparing PI with the true R using the stenosis of the internal carotid artery (ICA) as a clinical model. METHODS: The volume flow in the ICA was measured by a transit-time flowmeter in 400 patients undergoing carotid endarteriectomy. The pressure in the common carotid artery (CCA) proximal to and in the ICA distal to the stenosis was determined by direct puncture allowing the calculation of a pressure gradient (PG) and R in analogy to Ohm's law. R and PI were then correlated using Spearman's correlation. RESULTS: The blood flow in the ICA ranged from 2 to 478 ml/min with a median value of 165. The median PG was 14 mm Hg (0 to 88). Median R was 0.08 mm Hg x min / ml (0-26.5). PI varied between 0.8 and 114.1 with a mean of 1.9. Since a concentration of R and PI values in the lower ranges was observed, a logarithmic transformation was performed. Log PI showed only weak correlation to log R (r = 0.426, p < 0.0001). CONCLUSIONS: Log PI was intermediately correlated to log R in carotid artery stenosis, with a low discriminating power in the lower ranges due to the close distribution of measurements. Further studies are required to clarify the role of PI in hemodynamic questions and its general usefulness in other fields of vascular surgery like in peripheral bypass surgery.

Modulation of human adventitial fibroblast function by photodynamic therapy of collagen matrix.

OBJECTIVES: Photodynamic therapy (PDT) is a promising strategy to limit restenosis. PDT depletes the resident cells from the vessel wall without adventitial cell ingrowth. This study was undertaken to further explore the mechanisms by which PDT of matrix acts on key mechanisms in the development of restenosis. MATERIALS AND METHODS: Control and PDT-treated collagen type-I matrix gels were prepared. Thereafter, untreated human fibroblasts were seeded on matrix gels (n=12). Fibroblast proliferation and invasive migration were quantified by calibrated phase contrast microscopy. Fibroblast bFGF and TGF-beta1 mRNA expression were analyzed using a quantitative real-time reverse transcription polymerase chain reaction. RESULTS: Fibroblast proliferation on PDT-treated matrix gels was reduced by 30 and 76% after 3 and 7 days, respectively (3 days: P

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.

Intra-aneurysm sac pressure--the holy grail of endoluminal grafting of AAA.

OBJECTIVES: To relate intra-aneurysm sac pressure during endoluminal AAA repair to early and late endoleak, as well as to the aneurysm size upon follow-up. DESIGN: Prospective clinical investigation. METHODS AND PATIENTS: In 46 patients who had their AAAs treated by a stent graft (group I), intra-operative pressure measurement was performed (aorta uni-iliac stent grafts: 25 cases, bifurcated stent grafts: 21 cases). In 18 patients with open repair (group II) flow in the inferior mesenteric artery, and the pressure in the aneurysm sac was measured, before and after aortic and iliac cross clamping. Values are given in median with range. RESULTS: In group I, complete exclusion of AAA (no endoleak on intra-operative control angiogram) resulted in a statistically significant decrease in mean sac pressure from 74 (55-101) to 47 (4-104) mmHg. Pulse pressure reduced from 67 (34-103) to 8 (0-74) mmHg. In 11 patients a proximal type I endoleak was sealed by balloon modeling, after which the mean sac pressure reduced from 63 (14-91) to 52 (4-74) mmHg (n.s. versus patients with primary seal). Intra-operative pressure did not correlate with change in AAA diameter during twelve months follow-up. In group II, cross clamping of the proximal aorta significantly reduced mean sac pressure to 32 (21-55) mmHg, and the pulse pressure to 0 (0-13) mmHg (p < 0.05). Subsequent cross clamping of the iliac arteries did not significantly change the pressures. CONCLUSIONS: Measurement of intra-aneurysm sac pressure can help to detect and treat endoleaks during endoluminal grafting. However, the intra-operative sac pressure did not predict the fate of aneurysm during follow up. Compared to open repair of AAA, the sac pressure after endoluminal grafting remains significantly higher, in relation to pulse pressure.

Photodynamic therapy mediated induction of accelerated re-endothelialisation following injury to the arterial wall: implications for the prevention of postinterventional restenosis.

OBJECTIVE: Accelerated re-endothelialisation may inhibit the development of restenosis. Basic Fibroblast Growth Factor (bFGF) plays a key role for early proliferative activity in the artery following injury. Therefore, this study was devised to examine the effect of photodynamic therapy (PDT) on post-injury re-endothelialisation in vivo, and bFGF-mRNA expression in endothelial cells (EC) in vitro. MATERIALS AND METHODS: Rat carotid arteries were balloon-injured prior to PDT. Arteries were analysed after 1, 3, 5, 14 and 30 days. Morphometric measurements were undertaken following injection of 0.5% Evans Blue which stains non-endothelialised surfaces only. To identify EC, immunohistochemistry (CD-31) was performed. Proliferation was assessed by fluorescence cell counting. PCR quantification of bFGF-mRNA expression and proliferation were assessed in bovine aortic EC which were plated on isolated, PDT-treated EC-derived extracellular matrix at (12), 24, 48 (72 h). RESULTS: Three days following PDT, arteries displayed significantly increased endothelial lining (p = 0.02), which was more pronounced at 5 (p = 0.03) and 14 days (p = 0.02). At 30 days no relevant differences between PDT and control were noted. EC proliferation on PDT-treated matrix was significantly increased at 24, 48, and 72 h (p = 0.0004), whereas bFGF-mRNA expression was significantly increased at 24 h only (p = 0.007). CONCLUSION: Post-injury PDT appears to accelerate re-endothelialisation. Expression of bFGF-mRNA, however, although increased shortly after PDT, may not be responsible for a constant stimulation of EC proliferation.