Combined intermittent pneumatic leg compression and pharmacological prophylaxis for prevention of venous thromboembolism.

BACKGROUND: It is generally assumed by practitioners and guideline authors that combined modalities (methods of treatment) are more effective than single modalities in preventing venous thromboembolism (VTE), defined as deep vein thrombosis (DVT) or pulmonary embolism (PE), or both. This is the second update of the review first published in 2008. OBJECTIVES: The aim of this review was to assess the efficacy of combined intermittent pneumatic leg compression (IPC) and pharmacological prophylaxis compared to single modalities in preventing VTE. SEARCH METHODS: The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL, and AMED databases, and World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 18 January 2021. We searched the reference lists of relevant articles for additional studies.  SELECTION CRITERIA: We included randomised controlled trials (RCTs) or controlled clinical trials (CCTs) of combined IPC and pharmacological interventions used to prevent VTE compared to either intervention individually. DATA COLLECTION AND ANALYSIS: We independently selected studies, applied Cochrane's risk of bias tool, and extracted data. We resolved disagreements by discussion. We performed fixed-effect model meta-analyses with odds ratios (ORs) and 95% confidence intervals (CIs). We used a random-effects model when there was heterogeneity. We assessed the certainty of the evidence using GRADE. The outcomes of interest were PE, DVT, bleeding and major bleeding. MAIN RESULTS: We included a total of 34 studies involving 14,931 participants, mainly undergoing surgery or admitted with trauma. Twenty-five studies were RCTs (12,672 participants) and nine were CCTs (2259 participants). Overall, the risk of bias was mostly unclear or high. We used GRADE to assess the certainty of the evidence and this was downgraded due to the risk of bias, imprecision or indirectness. The addition of pharmacological prophylaxis to IPC compared with IPC alone reduced the incidence of symptomatic PE from 1.34% (34/2530) in the IPC group to 0.65% (19/2932) in the combined group (OR 0.51, 95% CI 0.29 to 0.91; 19 studies, 5462 participants, low-certainty evidence). The incidence of DVT was 3.81% in the IPC group and 2.03% in the combined group showing a reduced incidence of DVT in favour of the combined group (OR 0.51, 95% CI 0.36 to 0.72; 18 studies, 5394 participants, low-certainty evidence). The addition of pharmacological prophylaxis to IPC, however, increased the risk of any bleeding compared to IPC alone: 0.95% (22/2304) in the IPC group and 5.88% (137/2330) in the combined group (OR 6.02, 95% CI 3.88 to 9.35; 13 studies, 4634 participants, very low-certainty evidence). Major bleeding followed a similar pattern: 0.34% (7/2054) in the IPC group compared to 2.21% (46/2079) in the combined group (OR 5.77, 95% CI 2.81 to 11.83; 12 studies, 4133 participants, very low-certainty evidence). Tests for subgroup differences between orthopaedic and non-orthopaedic surgery participants were not possible for PE incidence as no PE events were reported in the orthopaedic subgroup. No difference was detected between orthopaedic and non-orthopaedic surgery participants for DVT incidence (test for subgroup difference P = 0.19).  The use of combined IPC and pharmacological prophylaxis modalities compared with pharmacological prophylaxis alone reduced the incidence of PE from 1.84% (61/3318) in the pharmacological prophylaxis group to 0.91% (31/3419) in the combined group (OR 0.46, 95% CI 0.30 to 0.71; 15 studies, 6737 participants, low-certainty evidence). The incidence of DVT was 9.28% (288/3105) in the pharmacological prophylaxis group and 5.48% (167/3046) in the combined group (OR 0.38, 95% CI 0.21 to 0.70; 17 studies; 6151 participants, high-certainty evidence). Increased bleeding side effects were not observed for IPC when it was added to anticoagulation (any bleeding: OR 0.87, 95% CI 0.56 to 1.35, 6 studies, 1314 participants, very low-certainty evidence; major bleeding: OR 1.21, 95% CI 0.35 to 4.18, 5 studies, 908 participants, very low-certainty evidence). No difference was detected between the orthopaedic and non-orthopaedic surgery participants for PE incidence (test for subgroup difference P = 0.82) or for DVT incidence (test for subgroup difference P = 0.69). AUTHORS' CONCLUSIONS: Evidence suggests that combining IPC with pharmacological prophylaxis, compared to IPC alone reduces the incidence of both PE and DVT (low-certainty evidence). Combining IPC with pharmacological prophylaxis, compared to pharmacological prophylaxis alone, reduces the incidence of both PE (low-certainty evidence) and DVT (high-certainty evidence). We downgraded due to risk of bias in study methodology and imprecision. Very low-certainty evidence suggests that the addition of pharmacological prophylaxis to IPC increased the risk of bleeding compared to IPC alone, a side effect not observed when IPC is added to pharmacological prophylaxis (very low-certainty evidence), as expected for a physical method of thromboprophylaxis. The certainty of the evidence for bleeding was downgraded to very low due to risk of bias in study methodology, imprecision and indirectness. The results of this update agree with current guideline recommendations, which support the use of combined modalities in hospitalised people (limited to those with trauma or undergoing surgery) at risk of developing VTE. More studies on the role of combined modalities in VTE prevention are needed to provide evidence for specific patient groups and to increase our certainty in the evidence.

Combined intermittent pneumatic leg compression and pharmacological prophylaxis for prevention of venous thromboembolism.

BACKGROUND: It is generally assumed by practitioners and guideline authors that combined modalities (methods of treatment) are more effective than single modalities in preventing venous thromboembolism (VTE), defined as deep vein thrombosis (DVT) or pulmonary embolism (PE), or both. This is an update of the review first published in 2008. OBJECTIVES: The aim of this review was to assess the efficacy of combined intermittent pneumatic leg compression (IPC) and pharmacological prophylaxis versus single modalities in preventing venous thromboembolism. SEARCH METHODS: For this update the Cochrane Vascular Information Specialist (CIS) searched the Specialised Register (May 2016). In addition the CIS searched the Cochrane Register of Studies (CENTRAL (2016, Issue 4)). Clinical trials databases were searched for details of ongoing or unpublished studies. SELECTION CRITERIA: Randomized controlled trials (RCTs) or controlled clinical trials (CCTs) of combined IPC and pharmacological interventions used to prevent VTE. DATA COLLECTION AND ANALYSIS: We independently selected trials and extracted data. Disagreements were resolved by discussion. We performed fixed-effect model meta-analyses with odds ratios (ORs) and 95% confidence intervals (CIs). We used a random-effects model when there was heterogeneity. MAIN RESULTS: We included a total of 22 trials (9137 participants) of which 15 were randomized trials (7762 participants). The overall risk of bias was mostly unclear or high due to selection and performance bias. We used GRADE to assess the quality of the evidence and this was downgraded from high to moderate or very low due to the risk of bias, imprecision or indirectness.The rate of PE in the studies comparing IPC alone with combined IPC and pharmacological prophylaxis was low, underpowering the analyses. The incidence of symptomatic PE was 0.79% with IPC, but ranged between 0.1 to 1% with combined IPC and pharmacological prophylaxis (OR 0.49, 95% CI 0.18 to 1.34; 12 studies, 3017 participants, moderate quality evidence). The incidence of DVT was 4.10% in the IPC group and 2.19% in the combined group showing a reduced incidence of DVT in favour of the combined group (OR 0.52, 95% CI 0.33 to 0.82; 11 studies, 2934 participants, moderate quality evidence). The addition of an anticoagulant to IPC, however, increased the risk of any bleeding compared to IPC alone; 0.66% (7/1053) in the IPC group and 4.0% (44/1102) in the combined group (OR 5.04, 95% CI 2.36 to 10.77; 7 studies, 2155 participants, moderate quality evidence). Major bleeding followed a similar pattern; 0.1% (1/1053) in the IPC group to 1.5% (17/1102) in the combined group (OR 6.81, 95% CI 1.99 to 23.28; 7 studies, 2155 participants, moderate quality evidence).We detected no difference between the type of surgery subgroups such as orthopedic and non-orthopedic participants for DVT incidence (P = 0.16). Tests for differences between type of surgery subgroups were not possible for PE incidence.Compared with pharmacological prophylaxis alone, the use of combined IPC and pharmacological prophylaxis modalities reduced the incidence of symptomatic PE from 2.92% to 1.20% (OR 0.39, 95% CI 0.23 to 0.64; 10 studies, 3544 participants, moderate quality evidence). The incidence of DVT was 6.2% in the pharmacological prophylaxis group and 2.9% in the combined group showing no difference between the combined and pharmacological prophylaxis groups (OR 0.42, 95% CI 0.18 to 1.03; 11 studies, 2866 participants, moderate quality evidence). Increased bleeding side effects were not observed for IPC when it was added to anticoagulation (bleeding: OR 0.80, 95% CI 0.30 to 2.14, very low quality evidence; major bleeding: OR 1.21, 95% CI 0.35 to 4.18, very low quality evidence, 3 studies, 244 participants).No difference was detected between the type of surgery subgroups for PE incidence (P = 0.68) or for DVT incidence (P = 0.10). AUTHORS' CONCLUSIONS: Moderate quality evidence suggests that combining IPC and pharmacological prophylaxis, compared with IPC or pharmacological prophylaxis alone, decreases the incidence of DVT when compared to compression, and incidence of PE when compared to anticoagulation. Moderate quality evidence suggests that there is no difference between combined and single modalities in the incidence of PE when compared with compression alone and DVT when compared with anticoagulation alone. The quality of evidence for PE or DVT was downgraded to moderate due to imprecision or risk of bias in study methodology, highlighting the need for further research. Moderate quality evidence suggests the addition of pharmacological prophylaxis to IPC, increased the risk of bleeding compared to IPC alone, a side effect not observed for IPC when added to pharmacological prophylaxis (very low quality evidence), as expected for a physical method of thromboprophylaxis. The quality of evidence for bleeding was downgraded to moderate due to indirectness or very low due to risk of bias in study methodology, indirectness and imprecision highlighting the need for further research. Nevertheless, the results of the current review agree with current guideline recommendations, which support the use of combined modalities in hospitalised patients (limited to those with trauma or undergoing surgery) at risk of developing VTE. More studies on the role of combined modalities in VTE prevention are needed.

Frequency, risk factors, and management of perigraft seroma after open abdominal aortic aneurysm repair.

OBJECTIVE: Perigraft seroma (PGS) causing enlargement of the native aneurysm sac after open abdominal aortoiliac aneurysm (AAA) repair is a rarely recognized complication with unknown clinical consequences. This study was undertaken to determine the frequency of PGS, identify associated risk factors, and review resulting complications and their management strategies. METHODS: Charts of all patients who underwent open AAA repair at our institution from 1995 to 2009 and had at least one postoperative abdominal cross-sectional imaging study (the study subjects) were retrospectively reviewed. PGS was defined as a perigraft fluid collection present > 3 months postoperatively, ≥ 3-cm in diameter and having a radiodensity ≤ 25 Hounsfield units on computed tomography (CT). Patient records were reviewed for demographics, comorbidities, operative and postoperative variables, and long-term outcome. RESULTS: Of the 111 study subjects identified, 13 had aortic reconstruction with Dacron grafts and 98 with polytetrafluoroethylene (PTFE) grafts. Twenty patients (18%) had PGS, all of whom had PTFE grafts (20 of 98; 20.4%). Mean age was 68.5 years and mean aneurysm diameter preoperatively was 6.4 cm (range, 4.0-10.9 cm). The average time from AAA repair to PGS detection was 51 months (range, 4-156 months). PGS averaged 6.0-cm in diameter (range, 3.0-11.0 cm). Multivariate analysis revealed that the following factors were associated with PGS development: diabetes (odds ratio [OR], 3.5; 95% confidence interval [CI], 1.1-21.2; P = .013), smoking (OR, 5.6; 95% CI, 0.73-33.74; P = .01), anticoagulation (OR, 7.2; 95% CI, 2.6-63.3; P = .003), bifurcated graft reconstruction (OR, 8.0; 95% CI, 2.6-94.1; P = .017), and left flank retroperitoneal approach for repair (OR, 7.1; 95% CI, 1.9-26.5; P = .003). Four patients (4 of 20; 20%) required intervention for PGS-related complications: 3 patients for symptomatic PGS expansion (1 patient with rupture) and 1 patient for acute limb ischemia secondary to graft limb compression and thrombosis. Two patients had open exploration, sac evacuation/reduction, and graft replacement with a Dacron graft: 1 patient for a ruptured aneurysm sac and 1 patient for persistent pain associated with sac enlargement. A third patient underwent a failed CT-guided drainage for abdominal pain and was subsequently treated with partial graft excision. The patient with acute limb ischemia was treated with catheter-directed thrombolysis and graft limb stenting. CONCLUSION: PGS after open AAA repair occurs more frequently than previously reported. Complications requiring intervention can occur in up to 20% of patients with PGS. A variety of treatment modalities can be used to deal with the complications. Earlier CT surveillance is advised after open AAA repair with a PTFE graft if symptoms are suggestive of PGS development.

Contemporary presentation and evolution of management of neck paragangliomas.

BACKGROUND: The aim of the present study was to review the contemporary presentation and evolution of management of neck paragangliomas. METHODS: Forty-one neck paragangliomas operated on in 36 patients over a 44 year period were included in the current report. The study period was divided into two parts, the first three decades (1964-1989), during which the current management techniques were evolved, and the last two decades (1990-2008). RESULTS: Patients presented with a palpable neck mass (n = 17), cranial nerve (CN) palsy (n = 3) or both (n = 6), or the lesion was an incidental finding (n = 14). The use of cross-section imaging modalities (n = 24) increased from 35% during the first part of the study to 95% during the second part of the study (P < .001). Preoperative embolization (introduced in 1979) was performed in 60% (median size 4.3 cm for embolized vs 3 cm [P = .02], for non-embolized tumors). During the first study period, the frequency of Shamblin group II/III tumors was 95% compared with a frequency of 42% during the second study period (P < .001, odds ratio 25), median blood loss was 600 ml and 150 ml, respectively (P = .001) and the transfusion rate was 44% and 5%, respectively (P = .008). The incidence of temporary and permanent new CN deficits postoperatively was 22.5% and 10%, respectively, and was similar during the two study periods. Three tumors were malignant, based on lymph node involvement (n = 1) or development of late metastases (n = 2). CONCLUSIONS: In the modern era, neck paragangliomas can be managed with a low incidence of long-term sequelae. Smaller, asymptomatic, and incidentally detected tumors are currently the most common presentation pattern.

Robotic-assisted laparoscopic dissection of the infrarenal aorta and iliac artery: a technical description and early results.

We report our initial experience with a novel robotic-assisted dissection of the infrarenal aorta and iliac arteries for the treatment of aortoiliac occlusive disease and abdominal aortoiliac aneurysm. Seven patients underwent the procedure using the da Vinci Surgical System. Transabdominal, retroperitonal dissection of the aorta and iliac arteries was completed using the robotic system; then, a mini-laparotomy and hand-sewn aorta-to-graft anastomosis were performed. There was no mortality in this series of patients. This novel technique may overcome the difficulty of aortic dissection in a purely laparoscopic aortic surgery and serves as a bridging step toward totally robotic-assisted aortic surgery.

Total robotic ligation of inferior mesenteric artery for type II endoleak after endovascular aneurysm repair.

We present a case of totally robotic ligation of the inferior mesenteric artery (IMA) for treatment of a persistent endoleak from the IMA into the aneurysm sac after endovascular aneurysm repair (EVAR). An 84-year-old male underwent EVAR with a Gore Excluder stent graft for an asymptomatic infrarenal abdominal aortic aneurysm. Follow-up computed tomographic (CT) scan showed persistent type II endoleak from the IMA, with progressive enlargement of the aneurysm sac from 5 to 6.1 cm over an 18-month period. In this case, the patient underwent ligation of the IMA using the da Vinci Surgical System for the treatment of retrograde flow into the aneurysm sac. The total operating time was 249 min; of this, the robotic assistance time was approximately 180 min. No intraoperative complications occurred. The estimated blood loss was 50 mL and the urine output 650 mL. The patient was extubated immediately after the procedure and tolerated a regular diet the following day. He was discharged home with a urinary catheter on postoperative day 2. CT scan postoperatively and at 3-month follow-up demonstrated an occluded IMA and stabilization of the aneurysm sac size.

Prospective comparison of the pneumatic cuff and manual compression methods in diagnosing lower extremity venous reflux.

AIM: To compare pneumatic cuff with manual compression in diagnosing reflux in patients with chronic venous insufficiency (CVI). PATIENTS AND METHODS: Eighteen patients (Clinical Etiologic Anatomic Pathophysiologic [CEAP 2-5], median Venous Clinical Severity Score [VCSS 6.5]) were studied. The VenaPulse device (ACI Medical, San Marcos, California) was used for cuff inflation. The hemodynamic performance of the 2 methods was tested in the first 9 patients, while their diagnostic value was tested in the last 9 patients. RESULTS: Both methods induced equal compression with median peak velocity of the antegrade flow (PVA) being 86 cm/s (P = .65). Coefficient of variation (CV) for PVA in the superficial veins was significantly higher with the manual method (16.8%) compared to the VenaPulse method (9.5%, P <.001), while sensitivity and specificity were 85% and 100%, and 78% (kappa .68, P <.001) and 100%, respectively. CONCLUSIONS: Pneumatic cuff and manual compression were shown to be equally effective in diagnosing venous reflux. Cost-effectiveness and ease-of-use studies comparing these methods are justified.

Thromboprophylaxis in radical retropubic prostatectomy: efficacy and patient compliance of a dual modality.

OBJECTIVES: The risk of developing venous thromboembolism (VTE) in urologic patients undergoing major surgery without thromboprophylaxis is high (up to 40%). The aims were to study the acceptability rate of and overall patient satisfaction with an automatic sequential leg compression system and the short-term effectiveness of a combined VTE prevention modality. METHODS: One-hundred and eighty-four consecutive patients undergoing radical retropubic prostatectomy were postoperatively treated with enoxaparine and intermittent pneumatic compression of the thigh. By completing a questionnaire, the patients were prospectively studied to evaluate the comfort and tolerability of a compression device (SCD Response Compression System; Covidien, Gosport, UK). The patients were monitored for complications and development of VTE for up to 4 weeks postoperatively. The device used ensures customized and effective compression therapy matching the patient's individual vascular refill by sequential, gradient, circumferential microprocessor-controlled compression cycles. RESULTS: No clinically evident VTE, critical bleeding or postoperative death occurred during the study period. Drain output was associated with transfusion requirement (p < 0.001), obesity (p < 0.02) and longer operation duration (p < 0.001). The sequential compression devices were well tolerated by 63% of the patients, in that the sleeves were judged as being pleasant (72%) and nonoppressive (79%). Patients reported bothersome insomnia (23%) and noise (44%), and early removal was required in 3%. CONCLUSIONS: Combined mechanical and pharmacological thromboprophylaxis was highly effective, well tolerated, and safe. The device tested showed a high comfort and tolerability profile. The use of combined modalities for VTE prophylaxis is justified in patients at very high risk of VTE, such as those undergoing radical retropubic prostatectomy.

Combined intermittent pneumatic leg compression and pharmacological prophylaxis for prevention of venous thromboembolism in high-risk patients.

BACKGROUND: It has been suggested that combined modalities (methods of treatment) are more effective than single modalities in preventing venous thromboembolism (defined as deep vein thrombosis and pulmonary embolism, or both) in high-risk patients. OBJECTIVES: To assess the efficacy of intermittent pneumatic leg compression combined with pharmacological prophylaxis versus single modalities in preventing venous thromboembolism in high-risk patients. SEARCH STRATEGY: The Cochrane Peripheral Vascular Diseases (PVD) Group searched their Specialized Register (last searched 17 July 2007) and the Cochrane Central Register of Controlled Trials (CENTRAL) (last searched The Cochrane Library 2008, Issue 3). We searched the reference lists of relevant articles to identify additional trials. SELECTION CRITERIA: Randomized controlled trials (RCTs) or controlled clinical trials (CCTs) of combined intermittent pneumatic leg compression and pharmacological interventions used to prevent venous thromboembolism in high-risk patients. DATA COLLECTION AND ANALYSIS: Data extraction was undertaken independently by two review authors using data extraction sheets. MAIN RESULTS: Eleven studies, six of them randomized controlled trials, were identified. The trials included 7431 patients, in total. Compared with compression alone, the use of combined modalities reduced significantly the incidence of both symptomatic pulmonary embolism (PE) (from about 3% to 1%; odds ratio (OR) 0.39, 95% confidence interval (CI) 0.25 to 0.63) and deep vein thrombosis (DVT) (from about 4% to 1%; OR 0.43, 95% CI 0.24 to 0.76). Compared with pharmacological prophylaxis alone, the use of combined modalities significantly reduced the incidence of DVT (from 4.21% to 0.65%; OR 0.16, 95% CI 0.07 to 0.34) but the included studies were underpowered with regard to PE. The comparison of compression plus pharmacological prophylaxis versus compression plus aspirin showed a non-significant reduction in PE and DVT in favor of the former group. Repeat analysis restricted to the RCTs confirmed the above findings. AUTHORS' CONCLUSIONS: Compared with compression alone, combined prophylactic modalities decrease significantly the incidence of venous thromboembolism. Compared with pharmacological prophylaxis alone, combined modalities reduce significantly the incidence of DVT but the effect on PE is unknown. The results of the current review support, especially in high-risk patients, the use of combined modalities. More studies on their role in PE prevention, compared with pharmacological prophylaxis alone, are urgently needed.

Novel NAD(P)H oxidase inhibitor suppresses angioplasty-induced superoxide and neointimal hyperplasia of rat carotid artery.

Neointimal proliferation occurring after vascular or endovascular procedures is a major complication leading to end-organ or limb ischemia. In experimental models, balloon injury has been shown to induce NAD(P)H oxidase to produce vascular superoxide anion (O2*-) production, which has been implicated in cell proliferation, but a direct link is still unclear. We postulated that inhibition of arterial NAD(P)H oxidase, resulting in decreased O2*-, would lessen the neointimal hyperplasia caused by balloon injury to the common carotid artery (CCA). Sprague-Dawley rats were implanted with osmotic minipumps containing either vehicle, a cell-permeant peptide that inhibits NAD(P)H oxidase (gp91ds-tat, 10 mg/kg per day), or a scrambled peptide control (scrmb-tat). Two days after pump implantation, the left CCA was injured using an intravascular balloon embolectomy catheter (2F Fogarty). Systolic blood pressure was monitored by tail cuff. Fourteen days after injury, CCAs were harvested and analyzed by digital morphometry. Rats in both groups remained normotensive, with no significant differences in systolic blood pressure. Reactive oxygen species measurements after injury indicated a significant reduction in vascular O2*- in rats infused with gp91ds-tat, and the neointima/media area and thickness ratios were significantly lower in their arteries compared with control. On the contrary, no significant change in overall CCA diameter was observed in any group. Our data indicate that in response to balloon injury of the rat carotid artery, NAD(P)H oxidase activity contributes to neointimal hyperplasia and is involved in vascular cell proliferation and migration during restenosis.

Infrainguinal endovascular procedures should be reserved for patients who do not have good open surgical options.

This article is the result of a debate. The motion proposed was "Infrainguinal endovascular procedures should be reserved for patients who do not have good open surgical options.'' Arguments in favor of the motion were offered by Daniel J. Reddy of Henry Ford Hospital in Detroit, MI, and arguments against the motion were offered by Peter Kalman of Loyola University Medical Center in Maywood, IL.

Equivalent secondary patency rates of upper extremity Vectra Vascular Access Grafts and transposed brachial-basilic fistulas with aggressive access surveillance and endovascular treatment.

OBJECTIVES: The 2006 update of the DOQI guidelines has stated that in patients with end-stage renal disease, autogenous radial-cephalic, or brachial-cephalic fistulas are the preferred access modalities, followed by transposed brachial-basilic (TBB) fistulas and prosthetic arteriovenous (AV) grafts. AV grafts are in general least preferred; however, there is very limited data comparing directly the last two modalities. The aim of the present study is to compare outcomes of the TBB fistula and the Vectra Vascular Access Graft. METHODS: Seventy-six patients had a prosthetic brachial-axillary Vectra graft placed, while in 41 patients brachial-basilic upper arm transposition was performed. Graft surveillance to detect a failing/failed access was followed by endovascular treatment, rheolytic thrombectomy (AngioJet, Possis Medical), and/or angioplasty +/- stenting of the responsible anatomical lesion(s). RESULTS: Use of Vectra grafts and TBB fistulas started after a median (interquartile range) of 14 (7-30) and 70 (52-102) days, respectively (P < .001), as early as the operative day in some patients with grafts. Postoperative complications were more frequent in TBB fistulas and late complications (mainly access thrombosis) in Vectra grafts. Total number of thrombectomy sessions performed for graft or fistula occlusion was 45 and 7, respectively (P = .032); total number of isolated angioplasty sessions, performed for failing graft or fistula was 31 and 45, respectively (P = .004). Although primary patency of the two access modalities was equivalent, primary assisted patency was significantly reduced in Vectra grafts (70% at 12 months and 58% at 18 months), compared with TBB fistulas (82% at 12 months and 78% at 18 months, P = .033); however, as a result of endovascular intervention, secondary patency rates at 12 months (87% vs 88%) and 18 months (87% vs 83%) were equivalent (P = .91). Presence of arterial anastomosis stenosis treated with angioplasty at any stage had a significant negative predictive value on secondary patency rates at 12 and 18 months which were 61%, compared with 96% for Vectra grafts that had any intra-graft, venous outflow, draining or central vein stenosis treated with angioplasty at any stage (P = .010). CONCLUSIONS: Aggressive graft surveillance and endovascular treatment methods can yield equivalent long-term secondary patency rates between Vectra graft and TBB fistulas. The advantage of earlier use of Vectra graft must be balanced against the need for more frequent secondary interventions and the risk of graft infection.

Results of aggressive graft surveillance and endovascular treatment on secondary patency rates of Vectra Vascular Access Grafts.

OBJECTIVE: The aim of the present study was to determine the effect of an aggressive graft surveillance and endovascular treatment protocol on secondary patency rates of a polyetherurethaneurea vascular access graft, specially designed to provide early access and rapid hemostasis. METHODS: One hundred and ninety Vectra Vascular Access Grafts (C. R. Bard, Inc, Murray Hill, NJ) were placed in 176 patients (78 females and 98 males, mean age 61.7 years). There were 41 forearm grafts, 145 upper arm grafts and four thigh grafts. Graft surveillance was performed by using clinical and hemodialysis parameters to detect a failing/failed graft and followed by endovascular treatment, rheolytic thrombectomy (AngioJet, Possis Medical Inc, Minneapolis, Minn) and/or angioplasty +/- stenting of the anatomical lesion (arterial anastomosis, graft, venous outflow, draining or central veins). RESULTS: Hemodialysis started after a median of 15.5 days, as soon as from the day of the operation in some cases. Bleeding complications occurred in six patients (3.2%), venous hypertension in seven (3.7%), steal syndrome in two (1.1%), neurological complications in two (1.1%), while late infection (range 2.7-14.6 months) was seen in six patients (3.2%). Thrombectomy and angioplasty (median number of sessions 1, interquartile range 1-2) was performed in 43 grafts. Isolated angioplasty, not associated with thrombosis (median number of sessions 1, interquartile range 1-2), was performed in 50 grafts. These interventions increased primary assisted patency from 69% and 63% at 12 and 18 months, respectively to a secondary patency rate of 86%. Taking into account grafts removed for late infection, functional secondary patency rate dropped to 83% and 81%, at 12 and 18 months, respectively. Arterial anastomosis angioplasty was performed more frequently in thrombosed grafts (28.6%) than failing grafts (6.7%), P < .001 and had a significant negative predictive value on secondary patency rates at 12 and 18 months, which were 60.5% compared with 89% for grafts that had no interventions performed (P = .007) and 90.9% for grafts that had any intra-graft, venous outflow, or draining or central vein stenosis treated with angioplasty at any stage (P = .002). Multivariate analysis identified the presence of arterial anastomosis stenosis as the single predictor of secondary patency (relative risk 0.247, P = .002). CONCLUSIONS: Aggressive graft surveillance and endovascular treatment increases significantly secondary patency rates of Vectra Vascular Access Grafts. Longer follow-up will determine the effectiveness of this policy. The role of inflow stenosis on graft longevity and alternative treatment options warrant further investigation.

Adventitial delivery of dominant-negative p67phox attenuates neointimal hyperplasia of the rat carotid artery.

Several essential components of NADPH oxidase, including p22phox, gp91phox (nox2) and its homologs nox1 and nox4, p47phox, p67phox, and rac1, are present in the vasculature. We previously reported that p67phox is essential for adventitial fibroblast NADPH oxidase O2- production. Thus we postulated that inhibition of adventitial p67phox activity would attenuate angioplasty-induced hyperplasia. To test this hypothesis, we treated the adventitia of carotid arteries with a control adenovirus (Ad-control), a virus expressing dominant-negative p67phox (Ad-p67dn), or a virus expressing a competitive peptide (gp91ds) targeting the p47phox-gp91phox interaction (Ad-gp91ds). Common carotid arteries (CCAs) from male Sprague-Dawley rats were transfected with Ad-control, Ad-p67dn, or Ad-gp91ds in pluronic gel. After 2 days, a 2-F (Fogarty) catheter was used to injure CCAs in vivo. After 14 days, CCAs were perfusion-fixed and analyzed. In 13 experiments, digital morphometry suggested a reduction of neointimal hyperplasia with Ad-p67dn compared with Ad-control; however, the reduction did not reach statistical significance (P = 0.058). In contrast, a significant reduction was achieved with Ad-gp91ds (P = 0.006). No changes in medial area or remodeling were observed with either treatment. Moreover, adventitial fibroblast proliferation in vitro was inhibited by Ad-gp91ds but not by Ad-p67dn, despite confirmation that Ad-p67dn inhibits NADPH oxidase in fibroblasts. These data appear to suggest that a multicomponent vascular NADPH oxidase plays a role in neointimal hyperplasia. However, inhibition of p47phox may be more effective than inhibition of p67phox at attenuating neointimal growth.

Perivascular gene transfer of NADPH oxidase inhibitor suppresses angioplasty-induced neointimal proliferation of rat carotid artery.

Vascular stretch induces NADPH oxidase-derived superoxide anion (O2-), which has been implicated in hypertrophy and cell proliferation. We hypothesized that targeted delivery of an NADPH oxidase inhibitor to the adventitia would reduce stretch-induced vascular O2- and attenuate neointima formation. We designed a novel replication-deficient adenovirus containing a fibroblast-active promoter driving expression of NADPH oxidase inhibitory sequence gp91ds (Ad-PDGFbetaR-gp91ds/eGFP). 1) We characterized the specificity of this promoter using pPDGFbetaR-luciferase by showing induction of luciferase in cultured rat aortic fibroblasts but not in vascular smooth muscle cells. 2) Using RT-PCR, we observed expression of gp91ds and the reporter gene in fibroblasts after infection with Ad-PDGFbetaR-gp91ds/eGFP. 3) Using Ad-CMV-eGFP as a control, we delivered Ad-PDGFbetaR-gp91ds/eGFP to the adventitia of the rat common carotid artery (CCA). Immunohistochemistry confirmed localized delivery of the inhibitor to the adventitia. After CCAs were injured with an embolectomy catheter, we observed a significant increase in neointima-to-media area ratio in control CCAs, which was significantly attenuated in CCAs treated with the gp91ds-expressing virus. In a second group of rats, we detected a 10-fold increase in distension-stimulated O2-, which was significantly reduced in CCAs infected with gp91ds-expressing virus. These data demonstrate that localized adventitial delivery of an NADPH oxidase inhibitor is effective in reducing overall vascular O2- and neointima formation, suggesting that adventitial NADPH oxidase plays a functional role in development of neointimal hyperplasia.

Adrenal insufficiency in patients with ruptured abdominal aortic aneurysms.

PURPOSE: Failure of the adrenocortical system after open repair of ruptured abdominal aortic aneurysm (RAAA) has never been reported, to our knowledge. This study was undertaken to examine the incidence and response to treatment of adrenal insufficiency in the RAAA population. METHODS: A 6-year retrospective analysis was carried out on data for all patients admitted after RAAA repair. A cosyntropin stimulation test (CST) was performed in patients with unexplained postoperative hypotension. Patients with adrenal insufficiency were given stress dose hydrocortisone, followed by slow hydrocortisone taper. RESULTS: Twenty of 26 patients admitted after RAAA repair survived longer than 1 week. Nine of these 20 patients underwent CST because of unexplained hypotension, and six patients were found to have adrenal insufficiency. Compared with the three patients with normal CST and the 11 patients with normotension who did not require testing, patients with adrenal insufficiency had greater preoperative hypotension (83% vs 29%; P =.05), greater operative blood loss (7.0 +/- 1.6 L vs 3.0 +/- 0.9 L; P =.003), longer lower extremity ischemia time (5.0 +/- 2.3 hours vs 1.3 +/- 0.5 hours; P =.025), and lower intraoperative urine output (0.8 +/- 0.4 mL/kg/hr vs 2.1 +/- 0.6 mL/kg/hr; P =.023). No difference in length of stay (40 +/- 18 days vs 35 +/- 26 days), major complications (27% vs 32%), or overall mortality (17% vs 15%) was demonstrated with steroid therapy. Initiation of steroid therapy enabled weaning of vasopressor support within 48 hours in patients with adrenal insufficiency. CONCLUSIONS: Adrenal insufficiency was identified in 67% of patients with RAAA with unexplained postoperative hypotension given a CST. Predictors of adrenal insufficiency after RAAA repair include preoperative hypotension and a complicated operative course. Steroid therapy can limit vasopressor dependence, and is not associated with increased morbidity or mortality.

Long-term outcome after mesenteric artery reconstruction: a 37-year experience.

PURPOSE: The purpose of this study was the definition of the late results and determining factors after mesenteric artery reconstruction (MAR) for atherosclerotic mesenteric ischemia. METHODS: A retrospective review identified 48 consecutive patients (66 arteries) who underwent MAR for acute mesenteric ischemia (AMI) of nonembolic origin (n = 23; 12 with and 11 without prior symptoms) and chronic mesenteric ischemia (CMI; n = 25) from 1963 to 2000 in a tertiary care referral center. The 29 women (60%) and the 19 men (40%) had a mean age of 64 years (range, 40 to 87 years). The operative procedures consisted of bypass grafting in 36 arteries (AMI, 12; CMI, 24), local endarterectomy (LEA) in 16 arteries (AMI, 9; CMI 7), and transaortic endarterectomy (TAE) in 14 arteries (AMI, 4; CMI, 10). The follow-up of the 34 survivors was complete in all but four patients and averaged 5.3 years (range, 30 days to 36 years). Radiographic documentation of vessel/graft patency was obtained in 33 of 34 survivors. RESULTS: Single-vessel revascularization was performed more frequently in the AMI group than in the CMI group (91% versus 48%; P =.001). The perioperative (<30 days) mortality rate in the AMI group was 52% (12 of 23 cases) as compared with 0 of 25 cases in the CMI group (P <.001). Bowel infarction was the cause of nine deaths. Major complications occurred in 60% of the cases. Fifteen late graft failures occurred, for a cumulative patency rate of 57% at 5 years and 46% at 10 years. TAE was associated with improved patency rates as compared with LEA (TAE versus LEA; P =.002). Symptomatic recurrences developed in eight patients, all involving superior mesenteric artery thrombosis (P <.001). The freedom-from-recurrence rates in the survivors were 79% at 5 years and 59% at 10 years. The late survival rates were 54% and 20% at 5 and 10 years, respectively. With the exclusion of perioperative deaths, the probability of long-term survival was 77% at 5 years and 29% at 10 years and did not differ between AMI and CMI. CONCLUSION: Although MAR for CMI carries a low mortality rate, AMI remains a lethal and frequently unheralded problem. Long-term patency and symptom-free survival can be expected after successful MAR for AMI and is comparable with those rates achieved after MAR for CMI. The patency of the SMA is important in the prevention of symptomatic recurrences. Elective MAR is indicated in patients with CMI and warrants long-term surveillance.

Long-term results of catheter-directed thrombolysis to treat infrainguinal bypass graft occlusion: the urokinase era.

PURPOSE: This study was undertaken to review the long-term results of catheter-directed thrombolysis in treatment of infrainguinal bypass graft occlusion. METHODS: From January 1987 to December 1998, 67 patients with 69 acutely occluded infrainguinal arterial bypass grafts (48 vein grafts, 21 prosthetic grafts) underwent treatment with catheter-directed thrombolysis with urokinase. Long-term results were assessed with Kaplan-Meier life-table analysis, and factors predictive of success were determined with multivariate analysis. RESULTS: Thrombolysis was aborted in 7 patients (10%) because of major complications or technical failure and was unsuccessful in restoring graft patency (

Safety and durability of redo carotid operation: an 11-year experience.

PURPOSE: With the recent emergence of carotid stenting in the management of carotid disease, the role of surgery has been challenged, particularly for recurrent carotid stenosis. This study was undertaken to determine the safety and durability of redo carotid operation (RCO) for recurrent stenosis. METHODS: A retrospective review identified 64 consecutive patients who underwent 66 RCOs between 1990 and 2000. There were 33 males (52%) and 31 females, with a mean age of 68.2 years (range, 38-84 years). The mean interval from the primary carotid surgery to RCO was 77.5 months (range, 1-292 months). Operative indications were severe asymptomatic stenosis in 33 cases (50%), transient ischemic attacks (TIA) or amaurosis fugax in 25 (38%), recent stroke in 6 (9%), and nonhemispheric symptoms in 1. Two operations were tertiary carotid reconstructions. A total of 56 (85%) patch angioplasties were performed, 49 with vein and 6 with synthetic material. Primary closure was performed in three cases (5%), whereas interposition grafts were required in eight (12%). Complete follow-up was available in 59 patients (92%) and averaged 4.3 years (range, 0.2-12.9 years); 97% of patients underwent follow-up duplex scanning. RESULTS: There were no operative deaths and only two operative strokes (3.1%). Permanent cranial nerve deficit occurred in one patient (1.5%). Late stroke occurred in five patients: four ipsilateral and one contralateral. Kaplan-Meier estimates for 5- and 10-year stroke-free survival were 92% and 74%, and for overall survival were 72% and 50%. Duplex scanning detected significant recurrent carotid stenosis (>80%) or occlusion in six cases (9%) at a mean follow-up of 4.1 years. Kaplan-Meier estimates for freedom from recurrent stenosis of >80% were 94% and 86% at 5 and 10 years. CONCLUSIONS: RCO for recurrent carotid stenosis can be performed safely with excellent protection from stroke and long-term durability. These data provide a standard against which the results of carotid stenting can be compared.