Modified Petticoat Technique with Pre-placement of a Distal Bare Stent Improves Early Aortic Remodeling after Complicated Acute Stanford Type B Aortic Dissection.

OBJECTIVE: This study evaluates the safety and efficacy of pre-placement of a distal bare stent as an adjunct to thoracic endovascular aortic repair (TEVAR) in the setting of complicated acute Stanford type B aortic dissection (cTBAD). METHODS: The records of all patients diagnosed with cTBAD at the institution between 2010 and 2013 were reviewed. Indications for the pre-placement of a distal bare stent included symptomatic malperfusion and/or radiological evidence of true lumen collapse. Computed tomography angiography was performed post-operatively to assess aortic remodeling. RESULTS: 148 patients were treated for cTBAD: 113 patients (76.4%) were treated with standard TEVAR and 35 (23.6%) were treated by combined proximal TEVAR with pre-placement of an adjunctive distal bare stent. Primary technical success was 95.9%. The 30 day mortality rate was 4.1% and was not different between groups. The 30 day morbidity included transient renal failure (10.1%), endoleak (7.4%), and paraplegia (2.7%), and was not different between groups. The mean follow up was 10 months (range 2-12 months). No late stent complications were observed; patients with an adjunctive bare stent had less distal re-dissection (0% vs. 15%; p = .01) and fewer endovascular re-interventions (5.7% vs. 20.4%; p = .04). At 1 year, patients treated with TEVAR and an adjunctive distal bare stent had increased true lumen volume (166 vs. 110 mL; p = .022), decreased false lumen volume (60 vs. 90 mL; p = .043), and increased complete false lumen thrombosis in the thoracic (76.5% vs. 29.5%; p < .001) and abdominal (20.6% vs. 3.8%; p = .002) segments. CONCLUSIONS: Combined pre-placement of a distal bare stent as an adjunct to proximal TEVAR to treat cTBAD restricts oversizing of the distal stent graft, reducing the potential for distal true lumen collapse and visceral malperfusion, and improving remodeling of the dissected thoracic aorta. Long-term follow up and prospective studies are needed to assess the overall effectiveness of this treatment strategy.

Aneurysm rupture after EVAR: can the ultimate failure be predicted?

OBJECTIVES: To provide insight into the causes and timing of AAA rupture after EVAR. DESIGN: Original data regarding AAA ruptures following EVAR were collected from MEDLINE and EMBASE databases. Data were extracted systematically and patient and procedural characteristics were analyzed. RESULTS: 270 patients with AAA ruptures after EVAR were identified. Causes of rupture included endoleaks (in 160: type IA 57, type IB 31, type II 23, type III 26, type IV 0, endotension 9, unspecified 14), graft migration 41, graft disconnection 11 and infection 6. Most of the described AAA ruptures occurred within 2-3 years after EVAR. Mean initial AAA diameter was relatively large (65 mm). No abnormalities were present in 41 patients during follow-up before rupture. Structural graft failure was described in 96 and a fatal course in 119 patients. CONCLUSIONS: Focus of surveillance on the first 2-3 years after EVAR may possibly reduce the AAA rupture rate, especially in patients with increased risk of early rupture (relatively large initial AAA diameter or presence of endoleak or graft migration). Better stent-graft durability and longevity is required to further reduce the AAA rupture risk after EVAR. Complete prevention will however remain challenging since AAA rupture may occur even if no predisposing abnormalities are present.

Hybrid surgical and endovascular therapy in multifocal peripheral TASC D lesions: up to three-year follow-up.

AIM: The authors described their three-year experience with hybrid surgical and endovascular therapy for multifocal peripheral TASC D lesions, involving both the aortoiliac and/or superficial femoral and common femoral arteries. METHODS: From February 2005 to March 2008, 21 lower limbs in 20 patients with multifocal peripheral artery disease, involving the aortoiliac and/or superficial femoral as well as common femoral arteries, were treated by hybrid surgical and endovascular therapy, such as aortoiliac and/or superficial femoral artery stenting as an adjunct to common femoral artery endarterectomy. Technical and hemodynamic success as well as primary and primary assisted patency and limb salvage rates were determined in concordance with the Society for Vascular Surgery guidelines. RESULTS: All lower limbs successfully underwent successful hybrid surgical and endovascular therapy. The average ABPI before and after hybrid therapy significantly increased from 0.50 +/- 0.32 to 0.79 +/- 0.24 (P = 0.0022). The mean duration of follow-up was 357 days (range, 4 to 1400 days). Over all, the primary patency rates were 94%, 70% and 70% at 6, 12, and 24 months, respectively, and the primary assisted patency rates were 94% at 24 months. The limb salvage rate was 100% at 24 months. The survival rates were 95%, 88%, and 88% at 6, 12, and 24 months, respectively. The primary patency rate for intermittent claudication was significantly higher that that for critical limb ischemia, while no significant difference was found in the assisted primary patency and survival rates between intermittent claudication and critical limb ischemia. CONCLUSION: Hybrid surgical and endovascular therapy, such as aortoiliac and/or superficial femoral artery stenting as an adjunct to common femoral artery endarterectomy, can provide a less invasive yet effective and durable option to patients with multifocal peripheral artery disease.

Fate of varicose veins after great saphenous vein stripping alone.

AIM: The aim of this study was to observe prospectively the clinical sequelae of varicose veins after great saphenous vein (GSV) stripping alone, and to examine whether spontaneous varicose vein regression or disappearance continued for a long period (>3 years). METHODS: Thirty-nine consecutive patients (20 males and 19 females; mean age 57.2), who underwent GSV stripping in Fujita Health University (55 limbs) between November 1, 2002 and December 31, 2003 were enrolled. RESULTS: At four to six weeks, varicose veins spontaneously resolved in 50 limbs (91%), in which subsequent sclerotherapy was not necessary. Five limbs subsequently underwent sclerotherapy for residual varicose veins (5%). At more than three years, 49 limbs (89%) completed the follow-up study. The recurrence after GSV stripping alone occurred in four of the 45 limbs (9%), while those of GSV stripping with sclerotherapy was one of the four limbs (25%). CONCLUSIONS: This study definitely demonstrated that spontaneous varicose vein resolution can continue for more than three years after GSV stripping alone, suggesting that varicectomy can be deferred or avoided in many patients.

Stent placement in the superficial femoral artery for patients on chronic hemodialysis with peripheral artery disease.

AIM: Chronic hemodialysis is associated with a high prevalence of peripheral artery disease (PAD), and patients on chronic hemodialysis with PAD have an increased risk of critical limb ischemia. The present study assessed the hemodynamic and clinical outcomes of stent placement in the superficial femoral artery (SFA) for patients on chronic hemodialysis. METHODS: Between February 2005 to August 2008, 43 consecutive lower limbs in 42 patients with SFA lesions that were successfully treated by primary stent placement were included in this study. Those were divided into a dialysis group (18 limbs) and a nondialysis group (25 limbs). Outcome measures included primary patency, assisted primary patency, limb salvage, and survival. RESULTS: Patients were significantly younger and presented with significantly more symptomatic limb ischemia in the dialysis group compared to the nondialysis group, despite comparable TransAtlantic Inter-Society Consensus (TASC) classification scores of SFA lesions between the two groups. The primary patency, primary assisted patency, limb salvage, and survival rates of the dialysis group were similar to those of the nondialysis group. CONCLUSIONS: Stent placement in the SFA is a feasible, safe, and effective procedure in patients on chronic hemodialysis with PAD, and may be offered as a first-choice therapeutic option for these patients.

Protective effect of sivelestat sodium (Eraspol) on postoperative lung dysfunction in patients with type A acute aortic dissection: a pilot study.

AIM: The authors evaluated the protective effect of sivelestat sodium on postoperative lung dysfunction in patients with type A acute aortic dissection who underwent aortic arch surgery with cardiopulmonary bypass (CPB) under deep hypothermia with circulatory arrest (DHCA). METHODS: Twelve patients with type A acute aortic dissection who underwent aortic arch replacement under CPB with DHCA and were pretreated with or without sivelestat sodium (sivelestat group, N.=7 patients; control group, N.=5 patients) were observed. The ratio of arterial oxygen tension to inspired oxygen fraction (P/F ratio) was measured as a parameter of pulmonary function before and after operation. The number of white blood cells was also counted as an index of inflammatory reaction before and after the operation. RESULTS: The P/F ratio decreased significantly after operation in the control group. However, the P/F ratio was unchanged between before and after operation in the sivelestat group. The number of white blood cells tended to increase after operation in the control group, whereas it decreased significantly after operation in the sivelestat group. CONCLUSION: The present study demonstrated the protective effect of sivelestat sodium on postoperative lung injury in patients with acute type A aortic dissection undergoing aortic arch surgery under CPB with DHCA.

Relationship between parameters of air plethysmography and types of superficial venous reflux in patients with primary varicose veins.

AIM: We investigated whether parameters of air plethysmography (APG) were correlated with types of superficial venous reflux as categorized by ascending venography in patients with primary varicose veins. METHODS: Two hundred and eight limbs with primary varicose veins in 135 patients were evaluated by both APG and ascending venography. Venous hemodynamics was assessed with APG. The location of incompetent vein segments was determined based on the results of ascending venography. RESULTS: Seventy-seven limbs had incompetence of the greater saphenous vein (GSV, G group), 36 had incompetence of the lesser saphenous vein (LSV, L group), and 77 had incompetence of the GSV and LSV (GL group). Twenty-five limbs did not have incompetence of the GSV or LSV (N group). The venous filling index (VFI) differed significantly between the N and the G and GL groups, the L group and the G and GL groups, and the G and GL groups. No significant difference was found between the N and L groups. The venous volume, ejection fraction, and residual volume fraction did not differ significantly among all four groups. CONCLUSION: The VFI as measured by APG discriminates well between limbs with incompetence of the GSV and those without incompetence of the GSV or LSV, and between limbs with incompetence of the GSV and those with the LSV in patients with primary varicose veins, suggesting that the hemodynamic severity of superficial venous reflux progresses with involvement from the LSV to the GSV to both saphenous veins.

Intermediate-term results of angioscopy-assisted anterior valve sinus plication for primary deep venous insufficiency.

AIM: The intermediate-term efficacy of angioscopy-assisted anterior valve sinus plication for primary deep venous insufficiency was evaluated. METHODS: Twelve limbs in 11 patients had class 4 or higher disease on the SVS/ISCVS classification. Descending venography revealed grade-3 or 4-reflux in all limbs. The limbs were treated with angioscopy-assisted anterior valve sinus plication of the highest valve of the superficial femoral vein. Clinical evaluation and air plethysmography were performed at the final follow-up. RESULTS: The mean follow-up was 38.4 months with a range of 24 to 48 months. Postoperative descending venography revealed significant improvement of the reflux of the superficial femoral vein. At the final follow-up, all patients reported relief of subjective symptoms. The ulcers healed and did not recur in the single limb with class-6 disease, the ulcers did not recur in four class-5 limbs, and there was a distinct clinical improvement with resolution of skin changes in the seven class-4 limbs. The venous filling index measured by air plethysmography was in a normal range in 8 of the 12 limbs. CONCLUSIONS: Angioscopy-assisted anterior valve sinus plication may be a surgical technique that results in intermediate-term clinical and hemodynamic improvement in patients with primary deep venous insufficiency.

Laser Doppler skin perfusion pressure in the diagnosis of limb ischemia in patients with diabetes mellitus and/or hemodialysis.

AIM: We investigated whether measurement of skin perfusion pressure (SPP), as measured by laser Doppler, can be used to evaluate the severity of limb ischemia in diabetes mellitus (DM) and/or hemodialysis (HD) patients. METHODS: From April 2004 to March 2005, the ankle brachial pressure index (ABPI) and SPP were evaluated in 44 consecutive lower limbs with peripheral artery disease (PAD) and in 24 patients (21 males and 3 females, aged from 45 to 84 years, with a mean age of 69.3 years) with DM and/or HD. Twelve limbs were categorized as Fontaine stage II, 19 as Fontaine stage III and 24 as Fontaine stage IV. RESULTS: The SPP did not differ significantly between limbs at Fontaine stage II and those at Fontaine stage III, but it was significantly lower in limbs at Fontaine stage IV than in those at Fontaine stage II or III. The ABPI did not differ significantly among limbs at Fontaine stages II, III and IV. CONCLUSION: The SPP, as measured by the laser Doppler technique, may be used as a standard for classifying the severity of PAD in patients with DM and/or HD.

Relationship between air-plethysmographic venous function and clinical severity in primary varicose veins.

AIM: The role of air plethysmography (APG) in the diagnosis of chronic venous insufficiency has not been well established. The purpose of this study was to elucidate the relationship between APG parameters and clinical severity in patients with chronic venous insufficiency. METHODS: Two hundred and ninety-four limbs in 154 patients with primary varicose veins were evaluated by APG. Limbs were categorized according to the clinical classification of chronic venous disease suggested by the Ad Hoc Committee on Reporting Standards in Venous Disease of the North American Chapter of the Society for Vascular Surgery and International Society for Cardiovascular Surgery (SVS/ ISCVS). RESULTS: The venous filling index (VFI) was significantly higher in classes 2, 3, 4, and 5+6 than in class 0 or 1, and did not differ among classes 2, 3, 4, 5+6. The ejection fraction did not differ significantly among the 6 classes, and the residual volume fraction was significantly higher in classes 2, 3, 5+6 than in class 0. CONCLUSIONS: APG is a reasonable method for distinguishing the presence or absence of chronic venous insufficiency, but it cannot discriminate the clinical severity. Among APG parameters, the VFI is the most useful diagnostic parameter in the evaluation of chronic venous insufficiency.

Presence of prostacyclin receptor in arteriosclerotic human femoral artery.

AIM: Prostacyclin, which is mainly synthesized by vascular endothelial cells, exerts antiplatelet and smooth-muscle-relaxant effects, thereby maintaining cardiovascular homeostasis. Prostacyclin analogues have been clinically proven to improve ischemic symptoms and prevent the occurrence of vascular events in the lower extremities of patients with arteriosclerosis obliterans. We examined the presence of prostacyclin receptor (IP receptor) in an arteriosclerotic human femoral artery. METHODS: Specimens of the femoral artery were obtained at the time of limb amputation from an 83-year-old woman. Atherosclerotic lesions and associated changes such as calcification were evident. The specimens were stained with hematoxylin and eosin, and processed for immunohistochemistry. RESULTS: A monolayer of cells was observed on the luminal side of the femoral artery. Single immunohistochemistry showed the presence of the IP receptors on cells of the luminal side of the femoral artery. Triple-immunofluorescence staining revealed colocalization of IP-receptor-positive cells and cells positive for von Willebrand factor, a marker of vascular endothelial cells. CONCLUSIONS: We investigated the presence of the IP receptor in the human femoral artery immunohistochemically, and demonstrated their strong expression in endothelial cells. This finding suggests that prostacyclin or prostacyclin analogues may act on their receptors on endothelial cells in patients with arteriosclerosis obliterans.

Shear stress and the endothelium.

Shear stress and the endothelium. Vascular endothelial cells (ECs) in vivo are influenced by two distinct hemodynamic forces: cyclical strain due to vessel wall distention by transmural pressure, and shear stress, the frictional force generated by blood flow. Shear stress acts at the apical cell surface to deform cells in the direction of blood flow; wall distention tends to deform cells in all directions. The shear stress response differs, at least partly, from the cyclical strain response, suggesting that cytoskeletal strain alone cannot explain it. Acute shear stress in vitro elicits rapid cytoskeletal remodeling and activates signaling cascades in ECs, with the consequent acute release of nitric oxide and prostacyclin; activation of transcription factors nuclear factor (NF)kappaB, c-fos, c-jun and SP-1; and transcriptional activation of genes, including ICAM-1, MCP-1, tissue factor, platelet-derived growth factor-B (PDGF-B), transforming growth factor (TGF)-beta1, cyclooxygenase-II, and endothelial nitric oxide synthase (eNOS). This response thus shares similarities with EC responses to inflammatory cytokines. In contrast, ECs adapt to chronic shear stress by structural remodeling and flattening to minimize shear stress. Such cells become very adherent to their substratum and show evidence of differentiation. Increased adhesion following chronic shear stress has been exploited to generate vascular grafts with confluent EC monolayers, retained after implantation in vivo, thus overcoming a major obstacle to endothelialization of vascular prostheses.

Accurate placement of microvascular guide sutures.

A simple technique to accurately place initial microvascular guide sutures is described. Enhanced suture placement enables anastomosis construction in situations in which the clamp must be placed very close to the vessel end or if the vessel lumen is distorted or poorly visualized. Because this technique eliminates the need for retraction on the guide suture tails, it is particularly useful for solo microvascular surgeons.

Expression and localization of vascular endothelial growth factor in normal abdominal aorta and abdominal aortic aneurysm.

AIM: The genesis of abdominal aortic aneurysms is associated with remodeling of the vascular wall by angiogenesis as well as proteolysis. Vascular endothelial growth factor (VEGF) is known to be a regulator of angiogenesis and to simultaneously stimulate elastolytic proteinases. We analyzed the expression and localization of VEGF in human abdominal aortic aneurysms compared to normal human aorta METHODS: Eighteen infrarenal aortic aneurysm samples were collected at the time of abdominal aortic aneurysm surgery, while nine normal aortic samples were obtained from autopsy specimens. Immunohistochemical staining was performed to detect VEGF. Immunoenzyme or immunofluorescent double staining was also used to identify those cells presenting VEGF. RESULTS: VEGF was expressed in 18 (100%) of the 18 abdominal aortic aneurysm samples, while 0 (0%) in the 9 normal abdominal aorta samples. Of the 18 samples of aneurysms, all 18 displayed positive VEGF immunostaining in macrophages, 12 in smooth muscle cells (SMCs), and 9 in endothelial cells (ECs). CONCLUSION: Our study clearly demonstrated the expression of VEGF in ECs, and SMCs, and macrophages of abdominal aortic aneurysms as well as its absence in those cells of normal abdominal aorta, suggesting that VEGF may play an important role in aneurysm formation via its direct and/or indirect actions.

Prostaglandin receptors EP2 and IP are detectable in atherosclerotic arteries and plaques.

AIM: Prostaglandin (PG) receptor agonists are frequently used for the pharmacological treatment of arteriosclerosis obliterans (ASO). In particular, the PG receptors EP2 and IP stimulate vasodilation and inhibit platelet aggregation, biological processes thought to be protective against ASO and important for physiological homeostasis. However it is uncertain whether EP2 and IP exist in diseased arteries, or what their distribution within the artery might be. In this study, we analyzed the distribution of these PG receptors in patients with severe ASO to determine the potential application of stimulation of these receptors as targets for pharmacological treatment. METHODS: We collected segments of atherosclerotic femoral arteries during femoropopliteal bypass surgery and determined the expression levels of EP2 and IP receptors by western blotting. Immunofluorescence was used to observe receptor localization. RESULTS: Findings of western blotting showed an increased Cox-2 expression in patients with ASO. The EP2 as well as IP receptors were each induced approximately 3-fold in comparison to normal samples. The expression of these receptors was increased in the intimal layer as well as the medial layer; their expression was also detectable within the atherosclerotic plaque. CONCLUSION: We observed induction of the PG receptors EP2 and IP in atherosclerotic femoral arteries in the arterial intima, medial layer, as well as the associated atherosclerotic plaque. These results suggest that receptor-selective PG agonists specifically target atherosclerotic arteries and therefore, may find potential application in the pharmacological management of patients with ASO.

Microcomputer-based programs for the practicing vascular surgeon.

An inexpensive microcomputer system can be programmed in BASIC to provide convenient data storage, retrieval, and analysis for the practicing vascular surgeon. A personalized registry program permits input of key patient data that can be processed and retrieved in list form or groupings with operator control of variables. A second program, in which lower extremity revascularization procedures can be analyzed by various parameters, is described. Results can be obtained in life-table formats with comparative statistical analysis. For the private practitioner of vascular surgery, the use of various computer programs will allow management of information for self-assessment, record keeping, teaching, and publication with great accuracy and at significant cost savings. In addition, word processing can increase secretarial output and efficiency. Office management programs are available but need to be individually investigated to determine their use for a particular practice. The major advantages of the microcomputer for the practicing vascular surgeon are personal control and ready access to data that are easy to store, analyze, and retrieve.

Protein secretion by the mouse blastocyst: differences in the polypeptide composition secreted into the blastocoel and medium.

To initiate studies on the protein microenvironment of the mouse blastocoel, we examined the electrophoretic profile of newly synthesized proteins secreted into the blastocoel, as well as those secreted into the medium. Although most polypeptides reveal no relative enrichment, some proteins (e.g., proteins of Mr = 155,000 and 33,000) are enriched in the blastocoel relative to those secreted apically into the medium. In addition, some proteins (e.g., proteins of Mr = 102,000 and 40,000) are enriched in the medium relative to the blastocoel. The relative amount of newly synthesized protein secreted into the blastocoel is about 2.5% of total protein synthesis. In addition, the trophectoderm and inner cell mass contribute to these proteins. Results of these studies suggest a potential function for these blastocoel-enriched proteins in inner cell mass development.

Changes in cAMP phosphodiesterase activity and cAMP concentration during mouse preimplantation development.

Cyclic nucleotide phosphodiesterase (PDE) activity and cAMP amounts were measured in mouse preimplantation embryos at the 1-cell, 2-cell, 8-cell/morula, and mid-blastocyst stages. PDE activity remained constant between the 1-cell and 2-cell stages. It decreased by the 8-cell stage and continued to decrease by the mid blastocyst stage to about 14% of the 1- and 2-cell values. By contrast, cAMP amounts remained essentially constant at 0.05 fmole/embryo (0.3 microM) from the 1-cell to the blastocyst stage and increased to 0.175 fmole in the fully expanded blastocyst that was close to hatching. Measurements of embryo volume indicated that intracellular volume remained essentially constant up to the blastocyst stage. The morphological changes in cell shape that accompany differentiation of the trophectoderm and that are coupled with blastocoel expansion decreased the intracellular volume. This decrease resulted in an increase in the cAMP concentration to about 0.4 microM by the mid-blastocyst stage. Previous studies indicate that either cAMP or TGF-alpha/EGF can stimulate the rate of blastocoel expansion. Although TGF-alpha/EGF can elevate cAMP levels in other cell types, TGF-alpha, at a concentration that maximally stimulates the rate of blastocoel expansion, did not elevate cAMP in blastocysts. Thus, it was unlikely that elevation of cAMP is the mechanism by which TGF-alpha stimulates the rate of blastocoel expansion.

Blastocoel expansion in the preimplantation mouse embryo: stimulatory effect of TGF-alpha and EGF.

The factors that promote blastocoel expansion in the preimplantation mouse embryo are not well understood. Since cAMP stimulates the rate of blastocoel expansion and, in other systems, EGF can elevate intracellular cAMP levels, we investigated the ability of either TGF-alpha or EGF to stimulate the rate of blastocoel expansion in the mouse. Picomolar concentrations of either TGF-alpha or EGF stimulate the rate of blastocoel expansion in a concentration-dependent manner, and the continual presence of the growth factor is required to observe the stimulatory effect. Neutralizing antibodies to either TGF-alpha or EGF inhibit the TGF-alpha or EGF stimulatory effect, respectively. An antibody to the extracellular domain of the EGF receptor stimulates the rate of blastocoel expansion in a concentration-dependent manner, whereas an antibody to the cytoplasmic domain of the receptor does not. Tyrphostin RG 50864, which inhibits the EGF receptor kinase activity, inhibits the TGF-alpha stimulation of the rate of blastocoel expansion in a concentration-dependent manner; the less active tyrphostin, RG 50862, has no inhibitory effect. In addition, TGF-alpha does not stimulate a precocious onset of cavitation. The stimulatory effect on the rate of blastocoel expansion elicited by TGF-alpha or EGF is observed in 70% of the embryos (responders). Responders and nonresponders have similar intracellular ATP levels and cell numbers. Whereas TGF-alpha stimulates the uptake of [35S]methionine into the acid-soluble and acid-insoluble pools in the responders, TGF-alpha has no stimulatory effect in the nonresponders. Results of these experiments suggest that an initial differentiative function of the first mammalian epithelium--fluid transport--is sensitive to peptide growth factor modulation.