Balloon catheter injury abolishes phenylephrine-induced relaxation in the rat contralateral carotid

BACKGROUND AND PURPOSE The consequences of compensatory responses to balloon catheter injury in rat carotid artery, on phenylephrine-induced relaxation and contraction in the contralateral carotid artery were studied. EXPERIMENTAL APPROACH Relaxation and contraction concentration-response curves for phenylephrine were obtained for contralateral carotid arteries in the presence of indomethacin (COX inhibitor), SC560 (COX-1 inhibitor), SC236 (COX-2 inhibitor) or 4-hydroxytetramethyl-L-piperidine-1-oxyl (tempol; superoxide dismutase mimetic). Reactive oxygen species were measured in carotid artery endothelial cells fluorimetrically with dihydroethidium. KEY RESULTS Phenylephrine-induced relaxation was abolished in contralateral carotid arteries from operated rats (E(max) = 0.01 +/- 0.004 g) in relation to control (E(max) = 0.18 +/- 0.005 g). Phenylephrine-induced contractions were increased in contralateral arteries (E(max) = 0.54 +/- 0.009 g) in relation to control (E(max) = 0.38 +/- 0.014 g). SC236 restored phenylephrine-induced relaxation (E(max) = 0.17 +/- 0.004 g) and contraction (E(max) = 0.34 +/- 0.018 g) in contralateral arteries. Tempol restored phenylephrine-induced relaxation (E(max) = 0.19 +/- 0.012 g) and contraction (E(max) = 0.42 +/- 0.014 g) in contralateral arteries, while apocynin did not alter either relaxation (E(max) = 0.01 +/- 0.004 g) or contraction (E(max) = 0.54 +/- 0.009 g). Dihydroethidium fluorescence was increased in contralateral samples (18 882 +/- 435 U) in relation to control (10 455 +/- 303 U). SC236 reduced the fluorescence in contralateral samples (8250 +/- 365 U). CONCLUSIONS AND IMPLICATIONS Balloon catheter injury abolished phenylephrine-induced relaxation and increased phenylephrine-induced contraction in contralateral carotid arteries, through O(2)(-) derived from COX-2.

Impaired calcium influx despite hyper-reactivity in contralateral carotid following balloon injury: eNOS involvement

Balloon catheter injury results in hyper-reactivity to phenylephrine in contralateral carotids. Decreased nitric oxide (NO) modulation and/or increased intracellular calcium concentration triggers vascular smooth muscle contraction. Therefore, this study explores the participation of NO signaling pathway and calcium mobilization on hyper-reactivity to phenylephrine in contralateral carotids. Concentration-response curves for calcium (CaCl(2)) and phenylephrine were obtained in control and contralateral carotids four days after balloon injury, in the presence and absence of the inhibitors (L-NAME, L-NNA, 1400W, 7-NI, Oxyhemoglobin, ODQ or Tiron). Confocal microscopy using Fluo-3AM or DHE was performed to detect the intracellular levels of calcium and reactive oxygen species, respectively. The modulation of NO on phenylephrine-induced contraction was absent in the contralateral carotid. Phenylephrine-induced intracellular calcium mobilization was not altered in contralateral carotids. However, extracellular calcium mobilization by phenylephrine was reduced in the contralateral carotid compared to control arteries, and this result was confirmed by confocal microscopy. L-NAME increased phenylephrine-induced extracellular calcium mobilization in the contralateral carotid to the control levels. Results obtained with L-NNA, 1400W, 7-NI, OxyHb, ODQ or Tiron showed that this response was mediated by products from endothelial NOS (eNOS) different from NO and without soluble guanylate cyclase activation, but it involved superoxide anions. Furthermore. Tiron or L-NNA reduced the levels of reactive oxygen species in contralateral carotids. Data suggest that balloon catheter injury promoted eNOS uncoupling in contralateral carotids, which generates superoxide rather than NO, and reduces phenylephrine-induced extracellular calcium mobilization, despite the hyper-reactivity to phenylephrine in contralateral carotids. (C) 2010 Elsevier B.V. All rights reserved.

An Apparent Paradox: Attenuation of Phenylephrine-mediated Calcium Mobilization and Hyperreactivity to Phenylephrine in Contralateral Carotid After Balloon Injury

Balloon catheter injury promotes hyperreactivity to phenylephrine (Phe) in the contralateral carotid. Phe-induced contraction involves calcium mobilization, a process that may be sensitive to reactive oxygen species. In this study, we investigated whether increased reactivity to Phe in the contralateral carotid is due to alterations in calcium mobilization by Phe and reactive oxygen species signaling. Concentration-response curves to Phe were obtained in control and contralateral arteries 4 days after balloon injury. Tiron did not modify E(max) to Phe in control arteries but reduced this parameter in the contralateral carotid to control levels. Moreover, immunofluorescence to dihydroethydine showed increased basal oxidative stress in the contralateral artery compared with control artery. Intracellular calcium mobilization by Phe in the contralateral artery was not different from control, but Phe-induced extracellular calcium mobilization was reduced in the contralateral artery compared with that in the control. These data were confirmed by confocal microscopy using Fluo 3-AM. Tiron and SC-236 increased Phe-induced calcium influx in the contralateral artery, which was similar to controls in the same conditions. However, catalase did not modify this response. Taken together, our results suggest that superoxide anions and prostanoids from cyclooxygenase-2 alter pathways downstream of alpha(1)-adrenoceptor activation in the contralateral carotid in response to injury. This results in reduced Phe-induced calcium influx, despite hyperreactivity to Phe.

A quantitative coronary angiography-matched comparison between a prospective randomised multicentre cutting balloon angioplasty and bare metal stent trial (REDUCE III) and the Rapamycin-Eluting Stent Evaluation At Rotterdam Cardiology Hospital (RESEARCH) study

Aims: There remains significant concern about the long-term safety of drug-eluting stents (DES). However, bare metal stents (BMS) have been used safely for over two decades. There is therefore a pressing need to explore alternative strategies for reducing restenosis with BMS. This study was designed to examine whether IVUS-guided cutting balloon angioplasty (CBA) with BMS could convey similar restenosis rates to DES. Methods and results: In the randomised REstenosis reDUction by Cutting balloon angioplasty Evaluation (REDUCE III) study, 521 patients were divided into four groups based on device and IVUS use before BMS (IVUS-CBA-BMS: 137 patients; Angio-CBA-BMS: 123; IVUS-BA-BMS: 142; and Angio-BA-BMS: 119). At follow-up, the IVUS-CBA-BMS group had a significantly lower restenosis rate (6.6%) than the other groups (p=0.016). We performed a quantitative coronary angiography (QCA) based matched comparison between an IVUS-guided CBA-BMS strategy (REDUCE III) and a DES strategy (Rapamycin-Eluting-Stent Evaluation At Rotterdam Cardiology. Hospital, the RESEARCH study). We matched the presence of diabetes, vessel size, and lesion severity by QCA. Restenosis (>50% diameter stenosis at follow-up) and target vessel revascularisation (TVR) were examined. QCA-matched comparison resulted in 120-paired lesions. While acute gain was significantly greater in IVUS-CBA-BMS than DES (1.65 +/- 0.41 mm vs. 1.28 +/- 0.57 mm, p=0.001), late loss was significantly less with DES than with IVUS-CBA-BMS (0.03 +/- 0.42 mm vs. 0.80 +/- 0.47 mm, p=0.001). However, no difference was found in restenosis rates (IVUS-CBA-BMS: 6.6% vs. DES: 5.0%, p=0.582) and TVR (6.6% and 6.6%, respectively). Conclusions: An IVUS-guided CBA-BMS strategy yielded restenosis rates similar to those achieved by DES and provided an effective alternative to the use of DES.

Use of an Inflatable Silicone Balloon Improves the Success Rate of Bladder Autoaugmentation at Long-Term Followup

Purpose: Most groups have reported disappointing results with autoaugmentation or detrusor myectomy for low capacity/compliance neuropathic bladders. Failure may be due to an ischemic diverticulum or mucosal shrinkage. We investigated whether a Silimed (R) silicone balloon placed in the bladder after autoaugmentation could prevent these problems, improving surgical results. Materials and Methods: We compared the results of standard bladder autoaugmentation in 12 children (group 1) with those in 10 (group 2) who underwent the same surgery using a bladder conformer. The conformer was a silicone balloon filled with saline that remained in the bladder for 2 weeks. All patients had a neuropathic bladder with poor capacity and compliance, resulting in urinary leakage between catheterizations. Preoperative and postoperative evaluation included a voiding diary, ultrasound, voiding cystourethrogram and urodynamics. Results: In group 1 only 1 patient became dry, 4 had little improvement in continence, 4 remained unchanged and 3 became worse. In group 2, 6 patients (60%) become continent without medication, 2 (20%) become continent with oxybutynin and 2 remained unchanged. Bladder capacity and compliance did not change significantly in group 1. However, in group 2 capacity changed from a mean of 140 to 240 ml and mean +/- SD compliance increased from 15.6 +/- 16.8 to 34.3 +/- 22.8 ml/cm H(2)O (p = 0.02). Conclusions: The inflatable balloon improved our long-term results of bladder auto-augmentation. A larger series may be necessary to confirm procedure efficacy and safety.

Treatment of ring slippage after gastric bypass: long-term results after endoscopic dilation with an achalasia balloon (with videos)

Background: Silastic rings are used in gastric bypass procedures for the treatment of obesity, but ring slippage may lead to gastric pouch outlet stenosis (GPOS). Conventional management has been ring removal through abdominal surgery. Objective: To describe a novel, safe, minimally invasive, endoscopic technique for the treatment of GPOS caused by ring slippage after gastric bypass. Design: Case series. Setting: Federal University of Pernambuco and sao Paulo University. Patients: This study involved 39 consecutive patients who-were screened for inclusion. Intervention: Endoscopic dilation with an achalasia balloon. Main Outcome Measurements: Technical success and safety of the procedure. Results: Among the 39 patients, 35 underwent endoscopic dilation at the ring slippage site for the relief of GPOS. The 4 patients who did not undergo endoscopic dilation underwent surgical removal of the ring, based on the exclusion criteria. The endoscopic approach was successful in 1 to 4 sessions in 100% of cases with radioscopic control (n = 12). The duration of the procedures ranged from 5 to 30 minutes, and the average internment was 14.4 hours. Dilation promoted either rupture (65.7%) or stretching (34.3%) of the thread within the ring, thereby increasing the luminal diameter of the GPOS. Complications included self-limited upper digestive tract hemorrhage (n = 1) and asymptomatic ring erosion (n = 4). There were no recurrences of obstructive symptoms during the follow-up period (mean of 33.3 months). Limitations: This was not a randomized, comparison study, and the number of patients was relatively small. Conclusion: The technique described promotes the relief of GPOS with low overall morbidity and avoids abdominal reoperation for ring removal. (Gastrointest Endosc 2010;72:44-9.)

A pilot study to evaluate the safety, tolerance, and efficacy of a novel stationary antral balloon (SAB) for obesity

Background: A 150 cm(3) pear-shaped gastric balloon with a 30 cm-long duodenal stem and a 7 g metallic weight at its distal end was designed and developed to facilitate weight loss by (a) delaying gastric emptying thus enhancing interprandial satiety, and (b) stimulating antral and duodenal receptors of satiation. Methods: Twenty-six patients (body mass index of 29 to 40 kg/m(2)) who failed to lose weight despite dietary intervention underwent endoscopic implantation of the balloon device. Patients were monitored for tolerance to the balloon, complications, weight loss, and compliance with a restricted caloric intake. Results: Six men and 20 women with a median body weight of 93.0kg (range, 73.5 to 119.9), median body mass index 34.3 kg/m(2) (range, 28.8 to 39.5) underwent balloon implantation for a median period of 4.0 months (range, 0.75 to 6.0). Twenty-two patients successfully complied with a 1250 to 1500 kcal daily diet restriction during the study period. Median weight reduction was 6.5 kg (range, 3.7 to 19.9). Patients with initial body weight of > 90 kg tended to loose more weight (8.1 kg) than patients weighing < 90 kg (4.5 kg) (P = 0.14). Nine patients with dwell times of 6 months lost 11.5 +/- 4.6 kg. The balloon malfunctioned in 4 patients (in I patient, the balloon leaked spontaneously but remained in the stomach and in 3 patients, the balloon migrated distally). Conclusions: Our novel balloon device may be effective in inducing weight loss by promoting compliance with a restricted caloric intake and is well tolerated due to its small size. Complications resulted from balloon rupture, which can be easily prevented by enhancements in design and use of alternative materials.

Small Bowel Endoscopy Using the Double-Balloon Technique: Four-Year Results in a Tertiary Referral Hospital in Brazil

Background: Double-balloon enteroscopy (DBE) allows evaluation and therapy for various small bowel diseases. In this series the outcome of a 4-year experience in a tertiary hospital school in Brazil is reported. Methods: A total of 457 consecutive DBE were performed in 418 patients from August 2004 to August 2008. 93 patients with several indications, whose aim was not the evaluation of suspected diseases of the small bowel mucosa, were excluded, therefore leaving 364 DBE in 325 patients for analysis. Data were retrospectively collected with regard to clinical, endoscopic findings, therapy and complications. Results: Among the 364 DBE performed in 325 patients, 143/325 were males (44%) and 182/325 females (56%) with a mean age of 48.6 +/- 15.7 years (range 17-89). Mean investigation time was 64 +/- 22 min (range 35-135). The depth of insertion beyond the ligament of Treitz was 230 +/- 85 cm (range 30-500) by the antegrade approach and 140 +/- 75 cm (range 0-320) by the retrograde approach. Total enteroscopy was achieved in 41.66% of the attempts (30 of 72 patients). Overall diagnostic yield was 54.95% (200 of 364 procedures) ranging from 0 to 100% in this series, depending on the indication. Angiodysplasia was the main diagnosis in 24.5% (49 of 200 procedures) and endoscopic treatment, including biopsies, hemostasis, tattooing and polypectomy were performed in 65.38% (238 of 364 procedures). No major complications were reported. Conclusions: DBE is a feasible, safe and well-tolerated procedure allowing endoscopic therapy. Selection of indications increases its diagnostic yield. Copyright (C) 2009 S. Karger AG, Basel

ERCP Using Double-Balloon Enteroscopy in Patients with Roux-en-Y Anatomy

Double-balloon enteroscopy (DBE) is a useful method for endoscopic retrograde cholangiopancreatography (ERCP) in patients with Roux-en-Y anatomy. Depending on the distorted anatomy, endoscopic therapies with conventional scopes were very difficult or impossible before the advent of DBE and patients had to be submitted to a percutaneous or surgical approach. The case of 6 patients with different types of Roux-en-Y-altered anatomy in which DBE-ERCP was performed with 83.3% successful rate (5/6) is reported confirming recent data in the literature on the feasibility of this method. Copyright (C) 2009 S. Karger AG, Basel

Secondary Lymphangiectasia of the Small Bowel: Utility of Double Balloon Enteroscopy for Diagnosis and Management

Sporadic lymphangiectasias are commonly found throughout the small bowel and are considered to be normal. Not uncommonly, lymphangiectasias are pathologic and can lead to mid-gastrointestinal bleeding, abdominal pain and protein-losing enteropathy. Pathologic lymphangiectasias of the small bowel include primary lymphangiectasia, secondary lymphangiectasia and lymphaticovenous malformations. In this report we present three different cases of small bowel lymphangiectasia detected by double balloon enteroscopy. The patients were diagnosed with South American blastomycosis, tuberculosis and primary small bowel lymphangioma. Copyright (C) 2009 S. Karger AG, Basel

Cardiovascular response during trigeminal ganglion compression for trigeminal neuralgia according to the use of local anesthetics

There are controversies about the use of local anesthetics during balloon compression for trigeminal neuralgia (TN) as a protective factor for cardiovascular events. The objective of this study was to investigate cardiovascular parameters (blood pressure and heart rate [HR]) of patients that underwent trigeminal balloon compression with local anesthetics compared to a control group (placebo). This is a randomized controlled study; 55 patients were randomized into two groups: study (deep sedation and trigeminal block with 0.8-mL lidocaine 2%) and control group (deep sedation and trigeminal injection of 0.8-mL saline). Blood pressure and HR were measured in five distinct moments: preoperative, during puncture for local anesthesia/placebo, during puncture with the catheter, during balloon compression, and final evaluation. Statistical analysis was performed with Pearson`s chi (2) and McNemar tests and the analysis of variance for repetitive measures. The means of systolic and diastolic blood pressures (SBP and DBP, respectively) were higher in the control group when compared to the study group at the evaluation during puncture with the catheter (p < 0.001) and balloon compression (p < 0.001 and p = 0.018 for DBP and SBP, respectively). There was an increase in the HR in the control group during the procedure (p = 0.017). The use of local anesthetics during the trigeminal balloon compression for TN can have a preventive role for the risk of cardiovascular events.

Perioperative Temporary Occlusion of the Internal Iliac Arteries as Prophylaxis in Cesarean Section at Risk of Hemorrhage in Placenta Accreta

Purpose The purpose of this study was to describe the preliminary results of prophylactic temporary balloon occlusion of the internal iliac arteries for bleeding control in patients with placenta accreta during cesarean hysterectomy. Methods From May 2006 to March 2010, 21 patients diagnosed with placenta accreta using ultrasound and/or magnetic resonance imaging were submitted to prophylactic balloon occlusion before hysterectomy. Fluoroscopy, balloon occlusion time, surgical duration, intraoperative blood loss, transfusion volume, and procedure complications were analyzed. Results The mean age was 30.5 years with a mean of 3.6 previous gestations. Imaging studies revealed that all patients had placenta accreta and all were submitted to cesarean hysterectomy. One hysterectomy was due to previous diagnosis of fetal death and another due to cesarean with uterine curettage. Mean fluoroscopy time was 7.5 min, balloon occlusion time was 164 min, and surgery duration was 260 min. Estimated blood loss was 1,671.5 ml with mean reposition fluids of 3,538 ml of crystalloids, 309.5 ml of colloids, and 1.24 ml of packed red blood cells. Two patients were submitted to thromboembolectomy due to prolonged surgical time. There was no maternal or fetal mortality related to the procedure. Conclusions The results demonstrated that prophylactic balloon occlusion of internal iliac artery is a safe method and appears to reduce blood loss and transfusion requirements in patients diagnosed with placenta accreta who undergo cesarean hysterectomy. Antenatal imaging diagnosis of placenta accreta enables preoperative planning.

Intimal dissection of the hepatic artery after thrombectomy as a cause of graft loss in pediatric living-related liver transplantation

HAT is the main cause of graft loss in pediatric living-related LTx. Revascularization of the graft by thrombectomy and re-anastomosis has been reported to be effective for graft salvage in cases of HAT and should be attempted when potential donors are not available for emergency re-transplantation. Immediate complications secondary to revascularization attempts in cases of HAT are not described. Late complications are mainly related to biliary tree ischemia. We report a case of child who experienced intimal hepatic artery dissection, which extended into intra-hepatic branches of the artery after a thrombectomy with a Fogarty balloon catheter in an attempt to restore arterial flow after HAT. This complication led to acute deterioration of the graft and the need for emergency re-transplantation.

Meta-analysis of infrapopliteal angioplasty for chronic critical limb ischemia

Background: Percutaneous transluminal angioplasty has been used with increasing frequency in the treatment of infrainguinal arterial occlusive disease. This meta-analysis aimed to assess the middle-term outcomes after crural angioplasty in patients with chronic critical limb ischemia and compare results with a meta-analysis of popliteal-to-distal vein bypass graft. Methods: Data were retrieved from 30 articles published from 1990 through 2006 (63% of articles published between 2000 and 2006). All studies used survival analysis, reported a 12-month cumulative rate of patency or limb salvage, and included at least 15 infrapopliteal angioplasties. The outcome measures were immediate technical success, primary and secondary patency, limb salvage, and patient survival. Data from life-tables, survival curves, and texts were used. Results. The pooled estimate of success was 89.0% +/- 2.2% for immediate technical result. Results at 1 and 36 months were 77.4% +/- 4.1% and 48.6% +/- 8.0% for primary patency, 83.3% +/- 1.4% and 62.9% +/- 11.0% for secondary patency, 93.4% +/- 2.3% and 82.4% +/- 3.4% for limb salvage, and 98.3% +/- 0.7% and 68.4% +/- 5.5% for patient survival, respectively. Studies with >75% of the limbs with tissue loss fared worse than their respective comparative subgroup for technical success and patency but not for limb salvage or survival. No publication bias was detected. Conclusion: The technical success and subsequent durability of crural angioplasty are limited compared with bypass surgery, but the clinical benefit is acceptable because limb salvage rates are equivalent to bypass surgery. Further studies are necessary to determine the proper role of infrapopliteal angioplasty.

Effectiveness of Thalidomide and Tamoxifen in Preventing Neointimal Hyperplasia in Experimental Vascular Injury in Rats

Introduction. Chronic allograft vasculopathy is an important cause of graft loss. Considering the inflammatory response in the development of chronic vascular lesions, therapeutic approaches to target the inflammatory process may be useful. We sought to investigate the possible protective effects on balloon catheter-induced vascular injury of thalidomide and tamoxifen, 2 drugs with powerful anti-inflammatory, immunomodulatory, and antifibrotic effects, using an animal model that mimics the morphologic features of chronic allograft vasculopathy. Methods. Male Wistar rats subjected to balloon catheter carotid injury (INJ) were treated with thalidomide (100 mg/kg), or tamoxifen (10 mg/kg), or vehicle. Contralateral right carotid arteries were used as uninjured controls. Morphometric and immunohistochemical analyses were performed at 14 days postinjury. Results. Injured carotid arteries showed marked neointimal hyperplasia, which was significantly inhibited among animals treated with thalidomide or tamoxifen: neointimal/media ratios of 1.4 +/- 0.4 versus 0.2 +/- 0.1 versus 0.4 +/- 0.2, for INJ, INJ + Thalid, and INJ + Tamox; respectively (P < .001). The endothelial cell loss was significantly less pronounced among animals subjected to carotid balloon injury that were treated with thalidomide (24 +/- 14 vs 1 +/- 1 cells per section in INJ, respectively (P < .05). Therapy with either thalidomide or tamoxifen effectively maintained alpha-smooth muscle actin expression in the media, similar to uninjured arteries. In this setting, tamoxifen was additionally effective to prevent the migration of myofibroblasts in to the intima. Conclusion. Thalidomide and tamoxifen were effective to reduce neointimal hyperplasia secondary to vascular damage. The vasculoprotective effects of thalidomide were more pronounced to preserve endothelial cells, whereas tamoxifen inhibited smooth muscle cell migration and proliferation. A possible beneficial effect of combined therapy with thalidomide plus tamoxifen should be addressed in future studies.