Serum procalcitonin (PCT) as a negative screening test for colonic ischemia after open abdominal aortic surgery.

BACKGROUND AND AIM: We assessed serum procalcitonin (PCT) as a screening test for early detection of ischemic colitis. PATIENTS AND METHODS: Ninety-three patients (81 men and 12 women) undergoing elective aortic surgery were enrolled in this study. Their mean age was 70.3+/-8.1 years old. Serum procalcitonin was measured postoperatively. RESULTS: Four patients suffered from colon ischemia. Based on a cut off value of serum PCT>/=2.0 ng/ml, fourteen patients had a false positive but none had a false negative result. Sensitivity was 100%, and specificity was 83.9% in detecting ischemic colitis. Negative predictive vale was 100%. CONCLUSION: Serum PCT is a non-invasive test that has a high negative predictive vale in ruling out colon ischemia after aortic surgery.

Effect of elastic compression stockings on oedema prevention in healthy controls evaluated by a three-dimensional measurement system.

BACKGROUND/AIMS: The degree of oedema may differ at various sites on the leg. This study evaluated the degree of oedema at the calf, ankle and foot using a three-dimensional measurement system. METHODS: By three-dimensional measurement system using the grid pattern projection method, the effects of four different types of elastic compression stockings on oedema prevention were compared in healthy subjects. RESULTS: Without stockings, a significant increase in the circumference and volume was seen at the ankle and foot in the evening compared with morning values. The average increase in circumference was greater at the foot than that at the ankle. A significant increase in circumference and volume in the evening after a day without stockings disappeared when elastic compression stockings were worn during the day. The coefficient of variation was greater for measurements at the foot than for those at the calf and ankle. CONCLUSION: Oedema develops easily in order of the foot, the ankle and the calf in healthy populations. Elastic stockings, even with a pressure as low as 8 mmHg, are effective on oedema prevention. In measurement at the foot, further developments are necessary to improve this system.

The retroperitoneum protects prosthetic graft material from intraperitoneal contamination: an experimental study.

OBJECTIVES: To evaluate the ability of the retroperitoneum to serve as a barrier, against bacterial contamination, between the peritoneal cavity to the retroperitoneal space. METHODS: Seventy rats had a small piece of knitted Dacron graft placed in the retroperitoneal space and 10(6)-10(9) colony forming unit (cfu) Enterococcus faecalis was injected into the peritoneal cavity. In half the retroperitoneal (RP) group, the retroperitoneum was preserved and in the remainder, the open peritoneal (OP) group, needle holes were created. Grafts were harvested after 1, 4, or 7 days and cultured for E. faecalis. A blood sample was collected from three rats in each group for culture before the graft was harvested. RESULTS: Graft infection did not develop in any rat injected with 10(6) or 10(7) cfu in the RP group, while seven out of the 10 graft cultures of the OP group grew E. faecalis (P = 0.003). In rats injected with 10(8) or 10(9) cfu, five out of the 10 graft cultures in the RP group and eight out of 10 in the OP group grew E. faecalis. All blood cultures were negative when the injected bacterial count was 10(7) cfu or less. One out of the three blood cultures was positive at 10(8) cfu, and all were positive at 10(9) cfu. CONCLUSIONS: These results suggest that an intact retroperitroneum acts as a protective barrier against intraperitoneal bacterial contamination, particularly when blood cultures are negative.

Healing of implanted expanded polytetrafluoroethylene vascular access grafts with different internodal distances: a histologic study in dogs.

OBJECTIVE: We assessed characteristics of healing, over time, of two types of expanded polytetrafluoroethylene grafts. STUDY DESIGN: An experimental histological study in dogs. METHODS: The graft types studied had the same internal diameter (5 mm) but different internodal distances. In one, the internodal distance was 60 microm in the external surface and 20 microm in the luminal surface. In the other, the internodal distance was 30 microm throughout the material. Sixteen grafts of each type were implanted between the femoral artery and vein in 16 dogs; explanted 1, 2, 4 or 12 weeks later; and examined histologically. RESULTS: In both graft types, infiltrating-cell density and maximum cell-penetration depth increased significantly between 1 and 2 weeks after implantation, but no significant increases occurred after 2 weeks. The number of inflammatory cells peaked 1 week after implantation and decreased significantly by 2 weeks. Subsequently, there were no significant changes in inflammatory cell numbers, suggesting that the inflammatory phase was over by 2 weeks after implantation and the grafts had become attached to surrounding tissue. There were no significant differences between the two graft types in cell density, cell-penetration depth, or number of inflammatory cells at any assessment time. CONCLUSION: Our results provide histologic support for guidelines recommending that synthetic vascular grafts for hemodialysis access should not be cannulated until 2 weeks after implantation. Since increasing the internodal distance to 60 microm in the external surface had no effect on graft healing, methods other than manipulation of internodal distance should be used in developing a graft suitable for early cannulation.

Effects of atherosclerotic plaque on the enlargement of an experimental model of abdominal aortic aneurysm in rabbits.

PURPOSE: Abdominal aortic aneurysm (AAA) usually is associated with atherosclerosis. We attempted to create an abdominal aortic aneurysm with atherosclerotic plaque in rabbits to investigate the relationship between atherosclerosis and enlargement of AAA. METHODS: An isolated segment of rabbit abdominal aorta was perfused with pancreatic elastase. Animals were fed a cholesterol-enriched diet to induce atherosclerotic plaque formation. Eight animals received perfusion with elastase and were fed a cholesterol-enriched diet (group EC), eight animals received perfusion with elastase and were fed a normal diet (group EN), eight animals received perfusion with saline and were fed a cholesterol-enriched diet (group SC), and eight animals received perfusion with saline and were fed a normal diet (group SN). Four animals served as a sham group. Each animal was killed after aortography at 4 or 12 weeks. The perfused segment was excised and examined histologically. RESULTS: No animal treated with saline and fed normal diet (groups SN) developed either an aneurysm or atherosclerosis. Atherosclerotic plaque was observed in animals fed the cholesterol-enriched diet (groups SC and EC) at 4 weeks, and the plaque had thickened further by 12 weeks. All animals treated with elastase (groups EN and EC) developed an AAA. Maximum internal diameter in groups EN and EC (4.1 mm) was equal at 4 weeks, but at 12 weeks, the diameter was less for group EC than for group EN (4.0 mm versus 4.8 mm, P<0.05). CONCLUSION: Cholesterol-enriched diet following the intra-luminal perfusion of an isolated aortic segment with elastase produced an AAA with atherosclerotic plaque in rabbits. It is likely that the thickened intima with atheroma suppressed continued enlargement of the aneurysm in this model.

Infrarenal aortic dilatation less than 4 cm is not unusual in patients with aortoiliac occlusive disease.

BACKGROUND: The relationship between atherosclerosis and abdominal aortic aneurysm is now controversial. To better define the contribution of atherosclerosis to the development of aneurysm of the infrarenal aorta, we determined the incidence of aortic dilatation in patients undergoing arterial reconstruction for an atherosclerotic aortoiliac occlusive disease (AIOD). The role of aortic wall calcification and intraluminal thrombus was also determined. SETTING: patients treated in a university hospital. SUBJECTS: 40 patients who underwent bifurcated graft bypass operation for AIOD without an abdominal aortic aneurysm =or>4 cm in size. MEASURES: Diameter, luminal calcification and intraluminal thrombus of the infrarenal aorta were evaluated using preoperative contrast enhancement computed tomography. RESULTS: Sixteen patients (40%) had an infrarenal aorta larger than the aorta at the level of the left renal vein. Of these, 5 patients (12.5%) had a 50% enlargement or more. Infrarenal aortic diameter correlated negatively with the extent of calcification of the infrarenal aorta and positively with the amount of intraluminal thrombus. CONCLUSIONS: Infrarenal aortic dilatation less than 4 cm in size is not unusual in patients with AIOD, suggesting a possible relationship between aortic atherosclerosis and dilatation. An aorta with atherosclerotic plaque containing abundant thrombus and few calcifications may develop enlargement.

SA channel mediates superoxide production in HUVECs.

Superoxide production in response to cyclic stretch (1 Hz, 20% in length) was investigated in human umbilical vein endothelial cells (HUVECs). The basal production of superoxide without stretch increased gradually, while the production of superoxide with stretch increased significantly as compared to that without stretch and it became significant 80 min after the onset of cyclic stretch (P<0.05, n=8-14). The superoxide production increased in a stretch-dependent manner and became significant when stretch was more than 10% (p<0.05, n=11-16). To investigate the involvement of SA channel, we added Gd3+ or EGTA in the reaction solution and examined the stretch-induced superoxide production. In cells stretched in the presence of 20 microM Gd3+, the stretch-induced superoxide production was significantly inhibited (at 120 min, p<0.05, n=8-18). The cyclic stretch-induced superoxide production was also significantly inhibited by the removal of extracellular Ca2+ with 5 mM EGTA (at 120 min, p<0.05, n=8-18). Neither the application of Gd3+ nor the removal of extracellular Ca2+ significantly changed the basal production of superoxide. These data suggest that the stretch-induced superoxide production increases in time- and stretch-dependent manner and that the stretch-induced superoxide production in HUVECs is regulated by Ca2+ influx through SA channels.

Comparison of argon-laser welded and sutured repair of inferior vena cava in a canine model.

BACKGROUND AND OBJECTIVE: Advantages of laser-welded microarterial anastomoses have been reported. However, whether laser repair of large veins is advantageous is not yet known. Argon-laser welding of inferior vena cava was therefore compared with conventional-sutured repair. STUDY DESIGN/MATERIALS AND METHODS: Twenty-four adult mongrel dogs were used. Twelve inferior vena cavas were repaired using an argon laser and the rest using continuous sutures. Specimens were removed at 2, 8, 16, and 24 weeks after repair. Technical characteristics, cavographical findings, and results of histopathological study using light and transmission electron microscopy were compared. RESULTS: Procedure time did not significantly differ between the two groups. The sutured repair sites were narrower than those repaired by laser immediately after and at 2 and 24 weeks. Histologically, laser welding resulted from denaturation of collagen and mild healing occurred simultaneously with the disappearance of denatured collagen. By contrast, there was strong fibrotic reaction at sutured repair sites. CONCLUSIONS: These findings suggest that argon-laser repair of large veins is superior to continuous suturing.

Skin sympathetic outflow in Buerger's disease.

To clarify if sympathetic outflow is altered in Buerger's disease (thromboangitis obliterans, TAO), we measured skin sympathetic nerve activity (SSNA) in TAO patients, and observed the sweating and vasoconstrictive responses during resting and with activating maneuvers. Multiunit postganglionic sympathetic activity was recorded in a skin fascicle of the tibial nerve innervating the skin of the sole (glabrous skin) and peroneal nerve innervating the skin of the dorsum pedis (hairy skin) from five TAO patients and five healthy subjects simultaneously with skin blood flow and sweat expulsion. TAO patients showed significantly less vasoconstrictor SSNA than healthy subjects (17.0+/-1.9 vs. 31.5+/-5.8 bursts/min, P<0.001). Moreover, we found no relationship between vasoconstrictor SSNA and skin blood flow in some patients, while they were well correlated in healthy subjects. There was no evidence for increased sympathetic activity in TAO patients, and no hypersensitive relationship was found between SSNA and skin blood flow. These observations suggested that these TAO patients exhibiting no relationship between skin blood flow reduction and vasoconstrictor activity might not respond to sympathectomy, which is generally expected to result in an increase in skin blood flow. The absence of increased sympathetic nerve activity provides further indirect evidence of a local vascular abnormality in TAO.

Sequelae after limb-sparing surgery with major vascular resection for tumor of the lower extremity.

PURPOSE: Limb-sparing procedures have recently replaced amputations as the treatment for tumors invading major vessels of the lower extremity. Major arteries must be reconstructed for limb salvage. The veins are not usually reconstructed. This study was undertaken to investigate the sequelae such as chronic venous disease after venous resection for tumors. METHODS: Ten patients who underwent limb-sparing surgery for a tumor of the lower extremity or retroperitoneum that required major vascular resection were studied. The median follow-up period was 48 months. After combined resection of a major artery and vein, arterial reconstruction was performed. The veins were not reconstructed. The resected veins included the inferior vena cava (n = 2), the external iliac and common femoral veins (n = 3), the superficial femoral vein (n = 3), and the popliteal vein (n = 2). The main outcome measures were clinical classification of chronic venous disease in 10 patients and air plethysmography in seven patients. RESULTS: Clinical classification was C(0A) in 6 patients, C(3A) in 1 patient, C(3S) in 2 patients, and C(4S) in 1 patient. Venous claudication with uncontrollable edema was observed in two patients with C(3S) disease. Pain and itching with inflammatory skin changes were observed in one patient with C(4S) disease. These three patients had undergone resection of the femoral vein, including the deep femoral vein along with proximal adductor muscles. Air plethysmography revealed that the ejection fraction was significantly lower and the residual volume fraction was significantly higher in the three patients with symptoms than in symptom-free patients. CONCLUSIONS: Significant chronic venous disease was observed in the patients who underwent combined resection of the femoral vein, the deep femoral vein, and the adductor muscles for a tumor.

Lack of association between the Met196Arg polymorphism in the TNFR2 gene and autoimmune diseases accompanied by vasculitis including SLE in Japanese.

A polymorphism in high-affinity receptor of TNF (TNFR2) gene, Met196Arg, was reported to be associated with systemic lupus erythematosus (SLE) in Japanese, whereas the association could not be found in Europeans at all and this represents an apparent discrepancy. The association, then, should be tested in other populations to clarify the possible involvement, if any, of the TNFR2 polymorphism in SLE or other related autoimmune diseases. The purposes of this study were to examine the TNFR2 polymorphism in Japanese patients with SLE and to investigate its association with other autoimmune diseases accompanied by vasculitis, mixed connective tissue disease, Buerger's disease, and Takayasu's arteritis. We found no association at all between the TNFR2 polymorphism and any autoimmune diseases including SLE in Japanese.

Clinical results of implantation of an endovascular covered stent-graft via midsternotomy for distal aortic arch aneurysm.

UNLABELLED: We have been implanting endovascular stent grafts (EVG) via midsternotomy for distal aortic arch surgery since February 1997. The early clinical results are evaluated. METHODS: There were 11 true aneurysms (8 fusiform, 3 saccular) and one chronic type B dissection. The average age was 68 yr (63-81). EVGs were PTFE-covered two-8 bend Z stents in the first eight cases and made with the same stents and ultrathin woven Dacron grafts in the last four cases. RESULTS: Total arch replacement and aortocoronary bypass grafting were combined in one and two patients, respectively. The average retrograde cerebral perfusion time was 42+/-8 min. The cardiopulmonary bypass time averaged 211+/-26 min. All patients awoke early after operation (4.5+/-1.2 h). All but one case was extubated within 24h. There was no operative mortality, but paraplegia and cerebral infarction were complicated in one case each. Their maximum diameter (73.9+/-21.2mm) decreased significantly after operation (68.7+/-20.1mm) and one year thereafter (63.1+/-16.0 mm). True aneurysms were thrombosed completely. A chronic type B dissection revealed impending rupture due to false lumen infection one year after operation. The whole descending aorta replacement was performed but the patient died 6 months thereafter due to cerebro-vascular complication. CONCLUSION: Implantation of EVGs reduces operative invasion for distal arch surgery. This procedure should improve mortality, while long-term results have not been clarified.

Fate of limbs with failed vascular reconstruction in Buerger's disease patients.

We surveyed the recent condition of lower limbs with failed vascular reconstruction in patients with Buerger's disease. Forty-three patients (mean age: 41.2+/-8.7 years) received infrapopliteal vascular reconstruction at Nagoya University Hospital. Symptoms at the time of surgery were intermittent claudication in 11 patients, rest pain in 13 and ulcer/gangrene in 19. Inquiry about the condition of the lower limbs was made during March 1998. Eight patients were lost to follow-up and three patients had died. In the remaining 32 patients, mean follow-up period was 140.5+/-42.0 months. Graft was occluded within a week after surgery in six patients with ischemic ulcer/gangrene, three of whom underwent a major amputation while the trophic lesion healed in the remaining three patients. Two grafts were occluded among the 11 patients with intermittent claudication. One of these patients had mild rest pain and the other reported intermittent claudication. Two of the patients with intermittent claudication were lost to follow-up. Among the 13 patients with rest pain, one had died and six were lost-to-follow-up. Although the remaining six patients complained of intermittent claudication, half had an occluded graft. Of the 19 patients with ulcer/gangrene, two had died and all nine of those with occluded graft complained of intermittent claudication. Fate of limbs with failed vascular reconstruction was satisfactory.

Pseudoaneurysm of the popliteal artery caused by exostosis of the femur: case report and review of the literature.

A 13-year-old boy with a solitary exostosis of the left femur was seen with a pseudo-aneurysm of the popliteal artery. When left leg pain occurred 3 months earlier, radiographic examination revealed an exostosis with a cartilage cap. Serial radiographic examination demonstrated gradual disruption of the cartilage cap of the exostosis as the pseudoaneurysm developed. An exostosis with an irregular surface was found at surgery. A literature review disclosed 39 similar cases in which loss of the cartilage cap was considered as one of the causes of the aneurysm formation. Considering the clinical course of our patient, however, we believe that exostoses lose their cartilage caps by pressure destruction due to the aneurysms. It is highly probable that loss of the cartilage does not cause the aneurysms.

Endovascular stent-graft deployment: temporary vena caval occlusion with balloons to control aortic blood flow-experimental canine study and initial clinical experience.

Vena caval occlusion was evaluated in animal experiments. In five patients with thoracic aortic aneurysms, two balloon catheters were introduced via the femoral vein to the inferior vena cava and superior vena cava and inflated before stent-graft deployment. Aortic pressure and flow were immediately decreased, which minimized the downstream shift of the stent-grafts. Temporary vena caval occlusion is safe and effective for precise aortic stent-graft deployment.

Intestinal permeability is increased in patients with intermittent claudication.

PURPOSE: Intermittent claudication can be regarded as repeated ischemia reperfusion injury, which can induce a generalized increase in vascular permeability, including in intestine. The lactulose mannitol test (L/M test) was performed in patients with intermittent claudication to evaluate the change in intestinal permeability when they were forced to walk. METHODS: The L/M test was performed in 11 patients with intermittent claudication and 11 control subjects without intermittent claudication. The test was performed at rest and after exercise. Patients walked on a treadmill until they stopped because of pain. The control subjects were forced to walk as far as 200 m on a treadmill. The L/M test was repeated in the patients after successful arterial reconstruction. Then the patients were instructed to walk the same distance at the same speed as they had before surgery. RESULTS: In patients, the mean L/M ratio after exercise was significantly higher than the mean L/M ratio when they were at rest (0.068 +/- 0.053 vs 0.022 +/- 0.009, P <.05). In control subjects, however, no significant difference was observed between the mean L/M ratios after exercise and at rest. The mean L/M ratio after exercise, decreased from 0.068 +/- 0.053 to 0.018 +/- 0. 016 after successful arterial reconstruction (P <.05) in patients. CONCLUSION: Intestinal permeability, determined by means of the L/M test, significantly increased in patients with intermittent claudication after exercise, and it diminished after arterial reconstruction. The L/M test is, consequently, a new noninvasive method to reflect ischemia in lower limbs during exercise.

Neutrophil and endothelial cell activation in the vasa vasorum in vasculo-Behçet disease.

AIM: The aim of this study was to analyse the immunopathological mechanisms of vasculo-Behçet disease, which were also compared to cases of Takayasu's arteritis and inflammatory aneurysm to evaluate differences in inflammatory mechanisms. METHOD AND RESULTS: We reviewed six cases of vasculo-Behçet disease, four of Takayasu's arteritis and seven inflammatory aneurysms which underwent surgical repair. Immunohistochemical studies were performed on paraffin-embedded tissue using a labelled streptavidin-biotin method, as was in-situ hybridization for Epstein-Barr virus. Microscopically, neutrophils and lymphocytes accumulated around the vasa vasorum. Neutrophils were prominent as compared to Takayasu's arteritis and inflammatory aneurysm. Elastic fibres were not severely destroyed. Endothelial cells (ECs) of most vasa vasorum expressed HLA-DR. The number of vasa vasorum around which inflammatory infiltrating cells were observed in vasculo-Behçet disease was significantly greater than in inflammatory aneurysms and Takayasu's arteritis (P < 0.001). The cytokines IL-1alpha, TNF-beta and IFN-gamma were expressed in neutrophils and lymphocytes which were distributed around vasa vasorum, as well as neutrophils adherent to HLA-DR positive ECs. CONCLUSION: Our results suggest that vasculo-Behçet disease should be classified as a neutrophilic vasculitis targeting the vasa vasorum. Aneurysm formation may be related to degeneration of arterial wall caused by inflammation of the vasa vasorum.

Relationship between aortic calcification and atherosclerotic disease in patients with abdominal aortic aneurysm.

BACKGROUND: Calcification of the aortic wall has been used as an index of the degree of complicated atherosclerotic plaque formation. Atherosclerosis in the abdominal aorta in patients with abdominal aortic aneurysm (AAA) was studied by measuring aortic calcification via computerised tomography. DESIGN: retrospective study. PATIENTS: preoperative computer tomography (CT) in 129 male patients with a mean age of 68.6 years (range: 42 to 82) undergoing elective aneurysmectomy. MEASUREMENTS: a conventional CT scanner was used. Aortic calcification was assessed at four levels: (A) the origin of the coeliac artery, (B) the left renal vein, (C) the maximum diameter of the aneurysm, and (D) the aortic bifurcation. Calcification was graded as: (0) no calcification, (1) calcification less than 40% of the aortic circumference, or (2) calcification more than 40% of the aortic circumference. The relationships between aortic calcification at each level and various factors related to atherosclerosis were analysed. RESULTS: Maximum calcification was seen at level D, followed by levels C, B and A, in that order. Calcification was less common in patients younger than 50 years old. Hypertension, coronary artery disease, and peripheral vascular occlusive disease correlated with the incidence of aortic calcification. CONCLUSIONS: A correlation between aortic calcification and atherosclerotic disease was demonstrated in patients with abdominal aortic aneurysm.

Implantation of an endovascular covered stent-graft for distal aortic arch aneurysm via midsternotomy under pigtail catheter guidance.

We implanted an endovascular covered stent-graft for distal aortic arch aneurysm involving the left subclavian artery in 12 cases. A stent-graft was delivered just below the aneurysm via aortotomy with direct vision using a 12 F delivery sheath under guidance of a pigtail catheter placed via the groin artery. The proximal anastomosis of the stent-graft was performed with inclusion technique, and the aortotomy was then closed with it. This technique reduces operative damage by eliminating distal anastomosis and should reduce operative mortality and morbidity.

[Preprocedural and procedural imaging modalities for transluminally placed endovascular grafting].

The vascular system can be evaluated with computed tomography (CT), magnetic resonance angiography (MRA), angiography, and computer-based CT image processing systems before successful transluminally placed endovascular grafting (TPEG). Noninvasive modalities are useful, but angiography is mandatory to determine whether TPEG is indicated. During the procedure, fluorography with a wide-image intensifier and high-resolution digital subtraction angiography are known to be essential, but intravascular ultrasonography is also indispensable to achieve accurate TPEG.