Miguel Ángel de Gregorio

Pulmonary Embolism Response to Fragmentation, Embolectomy, and Catheter Thrombolysis (PERFECT): Initial Results From a Prospective Multicenter Registry

BACKGROUND Systemic thrombolysis for acute pulmonary embolism (PE) carries up to a 20% risk of major bleeding, including a 2% to 5% risk of hemorrhagic stroke. We evaluated the safety and effectiveness of catheter-directed therapy (CDT) as an alternative treatment of acute PE. METHODS One hundred one consecutive patients receiving CDT for acute PE were prospectively enrolled in a multicenter registry. Massive PE (n = 28) and submassive PE (n = 73) were treated with immediate catheter-directed mechanical or pharmacomechanical thrombectomy and/or catheter-directed thrombolysis through low-dose hourly drug infusion with tissue plasminogen activator (tPA) or urokinase. Clinical success was defined as meeting all the following criteria: stabilization of hemodynamics; improvement in pulmonary hypertension, right-sided heart strain, or both; and survival to hospital discharge. Primary safety outcomes were major procedure-related complications and major bleeding events. RESULTS Fifty-three men and 48 women (average age, 60 years [range, 22-86 years]; mean BMI, 31.03 ± 7.20 kg/m2) were included in the study. The average thrombolytic doses were 28.0 ± 11 mg tPA (n = 76) and 2,697,101 ± 936,287 International Units for urokinase (n = 23). Clinical success was achieved in 24 of 28 patients with massive PE (85.7%; 95% CI, 67.3%-96.0%) and 71 of 73 patients with submassive PE (97.3%; 95% CI, 90.5%-99.7%). The mean pulmonary artery pressure improved from 51.17 ± 14.06 to 37.23 ± 15.81 mm Hg (n = 92) (P < .0001). Among patients monitored with follow-up echocardiography, 57 of 64 (89.1%; 95% CI, 78.8%-95.5%; P < .0001) showed improvement in right-sided heart strain. There were no major procedure-related complications, major hemorrhages, or hemorrhagic strokes. CONCLUSIONS CDT improves clinical outcomes in patients with acute PE while minimizing the risk of major bleeding. At experienced centers, CDT is a safe and effective treatment of both acute massive and submassive PE. TRIAL REGISTRY ClinicalTrials.gov; No.: NCT01097928; URL: www.clinicaltrials.gov.

New procedure for the treatment of colorectal neoplastic obstructions.

PURPOSE: A new procedure for the treatment of colorectal neoplastic obstructions is described. METHODS: This procedure involves the following phases: 1) placing a stent at the point of the stenosis of the colon, which enables the acute obstruction phase to be overcome; 2) recovering the general state of the patient, analyzing the development of the disease, and mechanically preparing the colon; 3) performing regulated and final surgery. RESULTS: In two patients, these three phases have been completed without complication and with excellent results. CONCLUSION: This procedure is both safe and effective and could become the method of choice for the treatment of colorectal neoplastic obstructions.

The Günther Tulip Retrievable Filter: Prolonged Temporary Filtration by Repositioning within the Inferior Vena Cava

PURPOSE To report experience with the retrievable Günther Tulip filter (GTF) as a means of temporary caval filtration for the prevention of pulmonary embolism (PE) with use of a technique that prolongs filter dwell time beyond 14 days. MATERIALS AND METHODS Eighty-eight GTFs were implanted in 87 patients. The GTFs were placed with the intention of retrieval in all patients within 14 days after initial implantation. In 23 of the 87 patients (26%), there was a need to prolong temporary caval filtration beyond the recommended period of 14 days. This was successfully achieved with use of percutaneous techniques from the right internal jugular vein whereby the filter was repositioned to a different location within the inferior vena cava (IVC) before definitive device removal. RESULTS Of 88 GTFs implanted in 87 patients, 70 were successfully retrieved and 18 were left in place permanently. Forty-seven filters in 46 patients were removed after initial implantation with no need for percutaneous repositioning within the IVC to prolong dwell time (mean dwell time, 13 days). In the 23 patients who required repositioning of 23 GTFs within the IVC to prolong temporary caval filtration, the mean dwell time was 34.8 days; the mean number of repositioning procedures was 1.5, the mean time between repositioning procedures was 13.8 days, and the mean fluoroscopy time was 4.4 minutes in patients in whom filter retrieval was attempted. One patient underwent placement and subsequent removal of the GTF twice for perioperative prophylaxis against PE on two separate occasions. No filters were misplaced in an unintended location or tilted (>15 degrees ) in relation to the main caval axis after deployment. In one patient, a GTF became permanently fixed in the IVC 16 days after initial implantation and could not be removed percutaneously. Nine patients had mild or moderate-sized cervical hematomas. One patient had recurrent asymptomatic PE 2 months after filter insertion. CONCLUSION Dwell times of 14 days can be achieved in most patients before device removal. Prolongation of the dwell time beyond 14 days can be safely and easily achieved by performing percutaneous repositioning of the device within the IVC via a jugular approach.

Mechanical and Enzymatic Thrombolysis for Massive Pulmonary Embolism

PURPOSE To assess the efficacy and safety of mechanical fragmentation combined with intrapulmonary thrombolysis in massive pulmonary thromboembolism (PTE) with hemodynamic impairment. MATERIALS AND METHODS Fifty-nine patients diagnosed with massive PTE with hemodynamic impact were treated. The initial clinical symptoms were shock in 23 patients (38.9%), syncope in eight (13.5%), and dyspnea at rest in 28 (47.4%). Mean O2 saturation was 67.8%. Mean pulmonary artery pressure (PAP) was 42.1 mm Hg. During fragmentation, thrombolysis was administered in the form of a urokinase bolus of 200,000-500,000 U in 57 patients and 20 mg of recombinant tissue plasminogen activator (rt-PA) in two patients. The mean urokinase dose used was 2,500,000 IU, whereas the total dose of rt-PA was 100 mg. Heparin sodium infusion was performed to reach activated partial thromboplastin time ratios of 2. The follow-up consisted of clinical assessment, pulmonary scintigraphy, and echocardiography. The patients received treatment with dicoumarin for 6 months after the procedure. RESULTS Clinical improvement was seen in 56 patients (94%). Three patients died. The mean PAP after the treatment was 21.8 mm Hg. The mean posttreatment Miller index was 0.35. Technical success was achieved in all cases and clinical symptoms improved in all cases except those in which the patients died. Pulmonary scintigraphy showed improved perfusion in all cases. Echocardiography was performed after 3-6 months, showing a mean pressure of 22.8 mm Hg (corrected values). There were no signs of recurrent PTE or arterial hypertension in the follow-up. CONCLUSION The data provided confirm the efficacy and safety of mechanical fragmentation and pharmacologic thrombolysis in the treatment of massive PTE with hemodynamic impairment, showing improvement of symptoms and a decrease in PAP.

Short- and long-term retrievability of the Celect vena cava filter: Results from a multi-institutional registry

PURPOSE To evaluate retrievability of the Celect vena cava filter over time and to assess the safety of the retrieval procedure in a prospective multicenter registry. MATERIALS AND METHODS Between October 2005 and March 2008, Celect filters were placed in 95 patients (61 men; mean age, 51 years +/- 18.5) with a temporary need for an inferior vena cava (IVC) filter. All patients satisfied requirements for filter placement; the primary indications for placement were pulmonary embolism (PE) with a contraindication to or failure of anticoagulation (n = 40), high risk for further PE (n = 29), trauma (n = 23), or massive PE with residual deep vein thrombosis and risk for further PE (n = 3). Filter orientation, vena cava injury, and other device-related incidents were evaluated at implantation and retrieval. The degree of difficulty associated with retrieval was also assessed. RESULTS Filter retrieval was attempted in 58 patients (mean indwell time of 179 days; median, 168.5 d; range, 5-466 d). Fifty-six filters (96.6%) were successfully retrieved. Unsuccessful retrieval attempts were attributed to filter tilt (n = 1) or excessive tissue growth with the hook embedded in the endothelium (n = 1). No adverse events were associated with the inability to retrieve these filters. A Kaplan-Meier product-limit survival estimate revealed that the probability of successful filter retrieval remained at 100% at 50 weeks and at more than 74% at 55 weeks after implantation. No adverse events were related to the retrieval procedures. CONCLUSIONS Retrieval of the Celect filter was performed safely as long as 466 days after implantation.

Retrieval of Gunther Tulip optional vena cava filters 30 days after implantation: a prospective clinical study.

PURPOSE To report on the feasibility and safety of retrieval of the Günther Tulip optional vena cava filter 30 days after initial implantation. MATERIALS AND METHODS From March 2004 to September 2005, a single-center prospective study was undertaken in 35 patients who required inferior vena cava (IVC) filtration. All the Günther Tulip filters (GTFs) were implanted with the intention to be removed 30 days after initial implantation. A modified commercial dynamometer was used to measure the force required to remove the device. The degree of difficulty to remove the GTF was classified into four levels: N (no difficulty, force of 0-4.41 N), M (medium difficulty, force of 4.41-5.88 N), G (great difficulty, force of 5.88-9.8 N), and U (unable to remove). Clinical follow-up was performed 1, 3, 6, and 12 months after filter retrieval by review of medical records and imaging. RESULTS Two of the 35 patients experienced extensive thrombosis in the IVC as revealed by abdominal computed tomography, and their filters were left in place on a permanent basis. One patient died of respiratory and cardiac failure during follow-up within the first 30 days after GTF insertion. Filter retrieval was attempted in the remaining 32 patients, and 31 of these attempts were successful (98%). The force necessary to disengage the GTF from the caval wall was less than 9.8 N (N, 79%; M, 13%; G, 6%). Attempts to remove the GTF failed in only one patient (2%). On follow-up times ranging between 14 and 640 days (mean, 342.5 d), no complications or cases of recurrent pulmonary embolism were observed in this patient population. CONCLUSION The Günther Tulip optional IVC filter can be safely placed and retrieved percutaneously 30 days after initial implantation.

Use of venous thromboembolism prophylaxis for surgical patients: a multicentre analysis of practice in Spain.

OBJECTIVE To assess the use of venous thromboembolism prophylaxis in surgical patients. DESIGN Retrospective multicentre study. SETTING Eight acute-care teaching hospitals with more than 400 beds, Spain. PATIENTS Medical records of all consecutive patients undergoing operations in the general surgical and trauma and orthopaedic services during the month of April, 1997, were randomly selected. INTERVENTION The sample size for each type of operation (general, trauma-orthopaedic) was calculated from the number of operations done at each hospital (with an absolute precision of 5%, and an alpha error of 5%) and the prevalence of the use of venous thromboembolism prophylaxis obtained from a random sample of 50 records (25 from patients in general surgery and 25 from patients in orthopaedic surgery) from each centre. MAIN OUTCOME MEASURES Appropriate and inappropriate pharmacological prophylaxis defined according to a combination of risk categories for venous thromboembolism, doses of antithrombotic agents given, time of starting prophylaxis, and its duration. RESULTS A total of 1848 medical records (general surgery, n = 1025; trauma-orthopaedic surgery, n = 823) were included. Physical methods (elastic stockings, intermittent pneumatic compression) were used in only 0.3% of patients. Pharmacological prophylaxis consisted of low molecular weight heparin in 99% of cases. The percentage given heparin-based prophylaxis was 54%. Overall, appropriate prophylaxis was given in 1175 patients (64%). Use of thromboprophylaxis ranged from 27% to 70% among the participating hospitals. Prophylaxis was more likely to be appropriate in orthopaedic patients (577, 70%) than in general surgical patients (598, 58%) in both the high and moderate risk categories. CONCLUSIONS Given the large variability between the participating hospitals, more specific protocols and recommendations about prophylaxis of thromboembolism in surgical patients are needed.

Improved perfusion system for bipolar radiofrequency ablation of liver: preliminary findings from a computer modeling study

Current systems for radiofrequency ablation of liver tumors are unable to consistently treat tumors larger than 3 cm in diameter with a single electrode in a single application. One of the strategies for enlarging coagulation zone dimensions is to infuse saline solutions into the tissue through the active electrodes. Nevertheless, the uncontrolled and undirected diffusion of boiling saline into the tissue has been associated with irregular coagulation zones and severe complications, mainly due to reflux of saline along the electrode path. In order to improve the perfusion bipolar ablation method, we hypothesized that the creation of small monopolar coagulation zones adjacent to the bipolar electrodes and previous to the saline infusion would create preferential paths for the saline to concentrate on the targeted coagulation zone. Firstly, we conducted ex vivo experiments in order to characterize the monopolar coagulation zones. We observed that they are practically impermeable to the infused saline. On the basis of this finding, we built theoretical models and conducted computer simulations to assess the feasibility of our hypothesis. Temperature distributions during bipolar ablations with and without previous monopolar coagulation zones were obtained. The results showed that in the case of monopolar coagulation zones the temperature of the tissue took longer to reach 100 degrees C. Since this temperature value is related to rise of impedance, and the time necessary for this process is directly related to the volume of the coagulation zone, our results suggest that monopolar sealing would allow larger coagulation zones to be created. Future experimental studies should confirm this benefit.

Fluoroscopic Management of Complications after Colorectal Stent Placement

Colorectal self-expanding metal stents have been widely used as a bridge to surgery in patients with acute malignant colonic obstruction by allowing a single-stage operation, or as a definitive palliative procedure in patients with inoperable tumors. Colonic stents are placed under either fluoroscopic or combined endoscopic and fluoroscopic guidance, with similar technical-success and complication rates. Placement of colonic stents is a very safe procedure with a low procedure-related mortality rate, but serious complications can develop and reinterventions are not uncommon. Most of the complications can be treated by minimally invasive or conservative techniques, while surgical interventions are required for most patients with perforation.

Retrievability of Uncoated Versus Paclitaxel-coated Günther-Tulip IVC Filters in an Animal Model

PURPOSE To compare in a pilot study, the retrievability and inferior vena cava (IVC) wall reaction elicited by uncoated and paclitaxel-coated Günther-Tulip filters in the animal model. MATERIALS AND METHODS Three groups with five pigs each underwent infrarenal IVC implantation of Günther-Tulip filters. Paclitaxel-coated filters were used in Groups A and B and uncoated filters were used in Group C. Filters were removed at 14, 19, 22, 26, and 30 days after implantation. A laparotomy was performed to remove filters from animals in group A and filters from animals in groups B and C that could not be retrieved via the right transjugular approach. Filter-induced venous wall changes were evaluated by examination of IVC venography, feasibility of filter removal at different implantation times, and laparotomy and microscopic findings. Feasibility of filter retrieval and venous wall changes were correlated. RESULTS IVC cavography showed no abnormality. Filters in animals in group B were uneventfully removed by a right jugular approach. Uncoated filter removal was not feasible in three of five animals in group C (19, 22, and 26 days). Microscopically, animals in group A had absent filter-induced IVC wall changes at 14, 19, 22, and 26 days and minimal changes at 30 days post implantation; animals in group B had absent filter-induced IVC wall changes at 14, 19, and 22 days and minimal changes at 26 and 30 days; animals in group C had moderate filter-induced IVC wall changes at 14 days and severe changes at 19, 22, 26, and 30 days. CONCLUSIONS This pilot study suggests that endothelial reaction to the presence of IVC filters in the porcine model is diminished by addition of paclitaxel coating to these filters. Further studies are necessary to substantiate these results.