Effects of dietary L -arginine on structure and function of flow-restricted vein grafts

AbstractPurpose: Experiments were designed to determine effects of dietary supplementation with L -arginine on structure and function of flow-restricted vein grafts. Methods: Saphenous veins were placed as bilateral interposition grafts in femoral arteries of two groups of adult male mongrel dogs; one group was maintained on a normal diet (control), the other group supplemented with L -arginine (200 mg/kg per day) beginning 1 week before surgery. In each dog, flow was reduced by 50% in one graft by placing an adjustable clamp on the artery distal to the distal anastomosis. Plasma amino acids and oxidized products of nitric oxide (NOx ) were measured before and after L -arginine feeding. At postoperative week 4, grafts were removed and prepared for organ chamber studies to determine functions of the endothelium or smooth muscle and for histology. Results: Plasma L -arginine increased within 3 hours after feeding and increased from 141 ± 8 nmol/mL to 169 ± 11 nmol/mL (n = 6) after 5 weeks of supplementation. Plasma ornithine and citrulline paralleled arginine, whereas circulating NOx was unchanged. Maximal contractions to 60 mmol/L KCl were reduced in grafts from L -arginine–fed dogs. Endothelium-dependent relaxations to the calcium ionophore A23187 and relaxations of the smooth muscle NO were reduced in grafts from L -arginine–fed dogs. Neointimal hyperplasia was increased in grafts with reduced flow and not affected by arginine feeding. Conclusions: Dietary supplementation with L -arginine did not increase plasma NO in dogs with peripheral vein grafts or increase endothelium-dependent relaxations in control or flow-restricted grafts. Therefore, dietary supplementation with L -arginine may not improve long-term functions of flow-restricted peripheral bypass grafts. (J Vasc Surg 2001;33:829-39.

The care of patients with varicose veins and associated chronic venous diseases: Clinical practice guidelines of the Society for Vascular Surgery and the American Venous Forum

The Society for Vascular Surgery (SVS) and the American Venous Forum (AVF) have developed clinical practice guidelines for the care of patients with varicose veins of the lower limbs and pelvis. The document also includes recommendations on the management of superficial and perforating vein incompetence in patients with associated, more advanced chronic venous diseases (CVDs), including edema, skin changes, or venous ulcers. Recommendations of the Venous Guideline Committee are based on the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system as strong (GRADE 1) if the benefits clearly outweigh the risks, burden, and costs. The suggestions are weak (GRADE 2) if the benefits are closely balanced with risks and burden. The level of available evidence to support the evaluation or treatment can be of high (A), medium (B), or low or very low (C) quality. The key recommendations of these guidelines are: We recommend that in patients with varicose veins or more severe CVD, a complete history and detailed physical examination are complemented by duplex ultrasound scanning of the deep and superficial veins (GRADE 1A). We recommend that the CEAP classification is used for patients with CVD (GRADE 1A) and that the revised Venous Clinical Severity Score is used to assess treatment outcome (GRADE 1B). We suggest compression therapy for patients with symptomatic varicose veins (GRADE 2C) but recommend against compression therapy as the primary treatment if the patient is a candidate for saphenous vein ablation (GRADE 1B). We recommend compression therapy as the primary treatment to aid healing of venous ulceration (GRADE 1B). To decrease the recurrence of venous ulcers, we recommend ablation of the incompetent superficial veins in addition to compression therapy (GRADE 1A). For treatment of the incompetent great saphenous vein (GSV), we recommend endovenous thermal ablation (radiofrequency or laser) rather than high ligation and inversion stripping of the saphenous vein to the level of the knee (GRADE 1B). We recommend phlebectomy or sclerotherapy to treat varicose tributaries (GRADE 1B) and suggest foam sclerotherapy as an option for the treatment of the incompetent saphenous vein (GRADE 2C). We recommend against selective treatment of perforating vein incompetence in patients with simple varicose veins (CEAP class C2; GRADE 1B), but we suggest treatment of pathologic perforating veins (outward flow duration ≥500 ms, vein diameter ≥3.5 mm) located underneath healed or active ulcers (CEAP class C5-C6; GRADE 2B). We suggest treatment of pelvic congestion syndrome and pelvic varices with coil embolization, plugs, or transcatheter sclerotherapy, used alone or together (GRADE 2B)

Early abdominal closure with mesh reduces multiple organ failure after ruptured abdominal aortic aneurysm repair: Guidelines from a 10-year case-control study

AbstractObjective: The objectives of this study were the comparison of patients who needed mesh closure of the abdomen with patients who underwent standard abdominal closure after ruptured abdominal aortic aneurysm repair and the determination of the impact of timing of mesh closure on multiple organ failure (MOF) and mortality. Methods: We performed a case-control study of patients who needed mesh-based abdominal closure (n = 45) as compared with patients who underwent primary closure (n = 90) after ruptured abdominal aortic aneurysm repair. Results: Before surgery, the patients who needed mesh abdominal closure had more blood loss (8 g versus 12 g of hemoglobin; P <.05), had prolonged hypotension (18 minutes versus 3 minutes; P <.01), and more frequently needed cardiopulmonary resuscitation (31% versus 2%; P <.01) than did the patients who underwent primary closure. During surgery, the patients who needed mesh closure also had more severe acidosis (base deficit, 14 versus 7; P <.01), had profound hypothermia (32°C versus 35°C; P <.01), and needed more fluid resuscitation (4.0 L/h versus 2.7 L/h; P <.01). With this adverse clinical profile, the patients who needed mesh closure had a higher mortality rate than did the patients who underwent primary closure (56% versus 9%; P <.01). However, the patients who underwent mesh closure at the initial operation (n = 35) had lower MOF scores (P <.05), a lower mortality rate (51% versus 70%), and were less likely to die from MOF (11% versus 70%; P <.05) than the patients who underwent mesh closure after a second operation in the postoperative period for abdominal compartment syndrome (n = 10). Conclusion: This study reports the largest experience of mesh-based abdominal closure after ruptured abdominal aortic aneurysm repair and defines clinical predictors for patients who need to undergo this technique. Recognition of these predictors and initial use of mesh closure minimize abdominal compartment syndrome and reduce the rate of mortality as the result of MOF. (J Vasc Surg 2002;35:246-53.

Inflammatory abdominal aortic aneurysms: A case-control study

AbstractPurpose: This study was designed to identify significant differences in the clinical and radiologic characteristics and outcome between patients with inflammatory and noninflammatory abdominal aortic aneurysms (AAAs).Methods: We reviewed 29 consecutive patients who underwent repair of an inflammatory AAA between 1985 and 1994. This group was matched in a case-control fashion by date of surgery and by the performing surgeon to a group of 58 patients who underwent repair of noninflammatory AAAs.Results: The two groups had comparable characteristics of age, gender, and cardiovascular risk factors. Patients with inflammatory AAAs were significantly more symptomatic than those with noninflammatory AAAs (93% vs 9%, p < 0.001), were more likely to have a family history of aneurysms (17% vs 1.5%, p = 0.007), and tended to be current smokers (45% vs 24%, p = 0.049). Thi most significant laboratory difference was an elevated sedimentation rate in patients with inflammatory AAAs (mean, 53 mm/hr vs 12 mm/hr, p < 0.00001). Inflammatory AAAs also were significantly larger than noninflammatory AAAs at presentation (6.8 cm vs 5.9 cm, p < 0.05). Although operative mortality was low in both groups, patients with an inflammatory AAA tended to have higher morbidity, including sepsis ( p < 0.01) and renal failure ( p = 0.04). Five-year survival rates, however, were similar for the two groups (79% for inflammatory and 83% for noninflammatory AAAs). On follow-up computed tomographic scans, the retroperitoneal inflammatory process resolved completely in 53% of the patients, but 47% of patients had persistent inflammation that involved the ureters in 32% and resulted in long-term solitary or bilateral renal atrophy in 47%.Conclusions: This case-control study provides preliminary evidence that inflammatory AAAs may have a relatively strong familial connection and that current smoking may play an important role in the inflammatory response. The study also documents that persistent retroperitoneal inflammation may be more prevalent than has been previously reported, and stresses the need for an improved understanding of the pathogenesis and long-term management of inflammatory AAAs. (J Vasc Surg 1996;23:860-9.

Contemporary management of acute mesenteric ischemia: Factors associated with survival

AbstractPurpose: Acute mesenteric ischemia (AMI) is a morbid condition with a difficult diagnosis and a high rate of complications, which is associated with a high mortality rate. For the evaluation of the results of current management and the examination of factors associated with survival, we reviewed our experience. Methods: The clinical data of all the patients who underwent operation for AMI between January 1, 1990, and December 31, 1999, were retrospectively reviewed, clinical outcome was recorded, and factors associated with survival rate were analyzed. Results: Fifty-eight patients (22 men and 36 women; mean age, 67 years; age range, 35 to 96 years) underwent study. The cause of AMI was embolism in 16 patients (28%), thrombosis in 37 patients (64%), and nonocclusive mesenteric ischemia (NMI) in five patients (8.6%). Abdominal pain was the most frequent presenting symptom (95%). Twenty-five patients (43%) had previous symptoms of chronic mesenteric ischemia. All the patients underwent abdominal exploration, preceded with arteriography in 47 (81%) and with endovascular treatment in eight. Open mesenteric revascularization was performed in 43 patients (bypass grafting, n = 22; thromboembolectomy, n = 19; patch angioplasty, n = 11; endarterectomy, n = 5; reimplantation, n = 2). Thirty-one patients (53%) needed bowel resection at the first operation. Twenty-three patients underwent second-look procedures, 11 patients underwent bowel resections (repeat resection, n = 9), and three patients underwent exploration only. The 30-day mortality rate was 32%. The rate was 31% in patients with embolism, 32% in patients with thrombosis, and 80% in patients with NMI. Multiorgan failure (n = 18 patients) was the most frequent cause of death. The cumulative survival rates at 90 days, at 1 year, and at 3 years were 59%, 43%, and 32%, respectively, which was lower than the rate of a Midwestern white control population (P <.001). Six of the 16 late deaths (38%) occurred because of complications of mesenteric ischemia. Age less than 60 years (P <.003) and bowel resection (P =.03) were associated with improved survival rates. Conclusion: The contemporary management of AMI with revascularization with open surgical techniques, resection of nonviable bowel, and liberal use of second-look procedures results in the early survival of two thirds of the patients with embolism and thrombosis. Older patients, those who did not undergo bowel resection, and those with NMI have the highest mortality rates. The long-term survival rate remains dismal. Timely revascularization in patients who are symptomatic with chronic mesenteric ischemia should be considered to decrease the high mortality rate of AMI. (J Vasc Surg 2002;35:445-52.

Factors affecting outcomes of open surgical repair of pararenal aortic aneurysms: A 10-year experience

PurposeFew large series document surgical outcomes for patients with pararenal abdominal aortic aneurysms (PAAAs), defined as aneurysms including the juxtarenal aorta or renal artery origins that require suprarenal aortic clamping. No standard endovascular alternatives presently exist; however, future endovascular branch graft repairs ultimately must be compared with the gold standard of open repair. To this end, we present a 10-year experience.MethodsBetween 1993 and 2003, 3058 AAAs were repaired. Perioperative variables, morbidity, and mortality were retrospectively assessed. Renal insufficiency was defined as a rise in the concentration of serum creatinine by ≥0.5 mg/dL. Factors predicting complications were identified by multivariate analyses. Morbidity and 30-day mortality were evaluated with multiple logistic regression analysis.ResultsOf a total of 3058 AAA repairs performed, 247 were PAAAs (8%). Mean renal ischemia time was 23 minutes (range, 5 to 60 minutes). Cardiac complications occurred in 32 patients (13%), pulmonary complications in 38 (16%), and renal insufficiency in 54 (22%). Multivariate analysis associated myocardial infarction with advanced age (P = .01) and abnormal preoperative serum creatinine (>1.5 mg/dL) (P = .08). Pulmonary complications were associated with advanced age (P = .03), renal artery bypass (P = .02), increased mesenteric ischemic time (P = .01), suprarenal aneurysm repair (P < .0008), and left renal vein division (P = .01). Renal insufficiency was associated with increased mesenteric ischemic time (P = .001), supravisceral clamping (P = .04), left renal vein division (P = .04), and renal artery bypass (P = .0002), but not renal artery reimplantation or endarterectomy. New dialysis was required in 3.7% (9/242). Abnormal preoperative serum creatinine (>1.5 mg/dL) was predictive of the need for postoperative dialysis (10% vs 2%; P = .04). Patients with normal preoperative renal function had improved recovery (93% vs 36%; P = .0002). The 30-day surgical mortality was 2.5% (6/247) but was not predicted by any factors, and in-hospital mortality was 2.8% (7/247). Median intensive care and hospital stays were 3 and 9 days, respectively, and longer stays were associated with age at surgery (P = .007 and P = .0002, respectively) and any postoperative complication.ConclusionsPAAA repair can be performed with low mortality. Renal insufficiency is the most frequent complication, but avoiding renal artery bypass, prolonged mesenteric ischemia time, or left renal vein transection may improve results

Control of disseminated intravascular coagulation in Klippel-Trenaunay-Weber syndrome using enoxaparin and recombinant activated factor VIIa: a case report

<p>Abstract</p> <p>Introduction</p> <p>Vascular malformation is associated with coagulopathies, especially when hemostasis is challenged.</p> <p>Case presentation</p> <p>We present the case of an 11-year-old Hispanic girl with Klippel-Trenaunay-Weber syndrome that developed disseminated intravascular coagulation after minor surgery, which was controlled by blood product transfusions and enoxaparin to address an ongoing consumptive coagulopathy. The patient, however, developed bacteremia and liver trauma that resulted in severe bleeding. To the best of our knowledge, we report here the first known instance of administering recombinant coagulation factor VIIa to control acute bleeding in a patient with Klippel-Trenaunay-Weber syndrome.</p> <p>Conclusions</p> <p>This case illustrates the concept of enoxaparin maintenance to suppress an ongoing consumptive coagulopathy and the use of recombinant coagulation factor VIIa to control its potentially fatal severe bleeding episodes.</p

The impact of transcranial direct current stimulation on inhibitory control in young adults

In recent years, many important discoveries have been made to challenge current policy, guidelines, and practice regarding how best to prevent stroke associated with atherosclerotic stenosis of the origin of the internal carotid artery. TheUnited States Center forMedicare andMedicaid Services (CMS), for instance, is calling for expert advice as to whether its current policies should be modified. Using a thorough review of literature, 41 leading academic stroke-prevention clinicians from the United States and other countries, have united to advise CMS not to extend current reimbursement indications for carotid angioplasty/stenting (CAS) to patients with asymptomatic carotid stenosis or to patients with symptomatic carotid stenosis considered to be at low or standard risk from carotid endarterectomy (CEA). It was concluded that such expansion of reimbursement indications would have disastrous health and economic consequences for the United States and any other country that may follow such inappropriate action. This was an international effort because the experts to best advise CMS are relatively few and scattered around the world. In addition, US health policy, practice, and research have tended to have strong influences on other countries. © 2012 The Authors. Published by Wiley Periodicals, Inc