Interspinous distraction in lumbar spinal stenosis: a neurophysiological perspective.

STUDY DESIGN: Prospective neurophysiological study. OBJECTIVE: To identify and quantify the neurophysiological effects of interspinous distraction during spine surgery for lumbar spinal stenosis (LSS). SUMMARY OF BACKGROUND DATA: Interspinous devices have been introduced as an alternative treatment of LSS in selected patients aiming at obtaining indirect decompression. Nevertheless, there is no data on the immediate neurophysiological effect of distraction. METHODS: Thirty patients with LSS undergoing decompression (14 at single level, 16 at multiple levels) were enrolled, resulting in a total of 48 levels to be analyzed. Before decompression, calibrated incremental distraction simulating interspinous device implantation of 8, 10, 12, 14, and 16 mm was performed. Intraoperative motor evoked potentials were acquired before any distraction, during distraction at each incremental value and after bilateral decompression. We evaluated relative changes of motor evoked potentials normalized to hand muscles and related them to the number of affected levels, LSS radiological severity based on the A to D grading, lordosis, and disc height. RESULTS: For single-level disease, 8-mm distraction and open decompression yielded similar improvement in motor evoked potentials not only in levels with morphological grades A or B, but also in levels with morphological grades C or D (i.e., severe or extreme stenosis) (P = 0.32). In contrast, distraction superior to 8 mm was less effective (P ≤ 0.05). In multiple-level stenosis, decompression was significantly more effective than any degree of distraction (P < 0.001). No correlation of those results to disc height or lordosis was observed. Using χ trend test to analyze the effect of distraction, a linear trend favoring moderate over severe stenotic morphology was observed (P = 0.0349). CONCLUSION: Interspinous distraction of 8 mm is sufficient to replicate electrophysiological improvements obtained during full decompression even in severe single-level stenosis but not in multilevel disease. Interspinous distraction has therefore an immediately measurable neurophysiological effect. Level of Evidence: 4.

Clinical results of autologous infrainguinal revascularization using grafts originating distal to the femoral bifurcation in patients with mild inflow disease.

AIM: Chronic critical limb ischemia (CLI) often requires venous bypass grafting to distal arterial segments. However, graft patency is influenced by the length and quality of the graft and occasionally patients may have limited suitable veins. We investigated short distal bypass grafting from the superficial femoral or popliteal artery to the infrapopliteal, ankle or foot arteries, despite angiographic alterations of inflow vessels, providing that invasive pressure measurement at the site of the planned proximal anastomosis revealed an inflow-brachial pressure difference of <or=10 mmHg. METHODS: Four hundred and twenty-three consecutive infrainguinal bypass grafts were performed for CLI between June, 1999 and November, 2002 at our institution. All patients underwent preoperative clinical examination, arteriography and assessment of the veins by duplex ultrasound. The study group are patients in whom the proximal and distal anastomoses of the bypass are below the femoral bifurcation and the popliteal artery, respectively. Invasive arterial pressure measurements were recorded at the level of the planned proximal anastomosis which was performed at that level if the difference of the inflow-brachial pressure was <or=10 mmHg, irrespective of angiographic alterations of the inflow vessels proximal to the planned anastomosis. All patients had a clinical follow-up included a duplex examination of their graft, at 1 week, 3, 9 and 12 months and, thereafter, annually. No patient was lost to follow-up. RESULTS: Sixty-seven patients underwent 71 short distal bypass grafts in 71 limbs with reversed saphenous vein grafts in 52, in situ saphenous veins in 11, reversed cephalic vein in 1 and composite veins in 7, respectively. Surgical or endovascular interventions to improve inflow were required in 4 limbs (5.6%). The mean follow-up time was 22.5 months and the two-year survival was 92.5%. Primary and secondary patency rates at 2 years were 73% and 93%, respectively, and the limb salvage rate was 98.5%. CONCLUSION: In appropriately selected patients, short distal venous bypass grafts can be performed with satisfactory patency and limb salvage rates even in the presence of morphologic alterations of the inflow vessels providing that these are not hemodynamically significant, or can be corrected intraoperatively.

Which available transapical transcatheter valve fits into degenerated aortic bioprostheses?

The transapical transcatheter aortic valve implantation (TA-TAVI) in degenerated aortic bioprosthesis is an emerging therapy for surgically non-amenable patients. However, the presence of different types of aortic bioprostheses (stented and stentless), available in different sizes (19-27 mm), can be at the origin of important mismatches between the malfunctioning, degenerated aortic valves and the inner stent-valves implanted through transapical accesses (23 and 26 mm Edwards Sapien transcatheter stent-valves). We report an emergency TA-TAVI treatment of a severely regurgitant degenerated 23 mm Mitroflow aortic bioprosthesis (Sorin Group, Milano, Italy) implanted seven years earlier in an 80-year-old lady, and we reviewed the current available literature about transapical 'valve-in-valve' procedures to analyze the hemodynamic results and the ideal 'prosthesis-to-prosthesis' match.

Peri-operative management of antiplatelet therapy in patients with coronary artery disease. Joint position paper by members of the working group on Perioperative Haemostasis of the Society on Thrombosis and Haemostasis Research (GTH), the working group on Perioperative Coagulation of the Austrian Society for Anesthesiology, Resuscitation and Intensive Care (ÖGARI) and the Working Group Thrombosis of the European Society for Cardiology (ESC).

An increasing number of patients suffering from cardiovascular disease, especially coronary artery disease (CAD), are treated with aspirin and/or clopidogrel for the prevention of major adverse events. Unfortunately, there are no specific, widely accepted recommendations for the perioperative management of patients receiving antiplatelet therapy. Therefore, members of the Perioperative Haemostasis Group of the Society on Thrombosis and Haemostasis Research (GTH), the Perioperative Coagulation Group of the Austrian Society for Anesthesiology, Reanimation and Intensive Care (ÖGARI) and the Working Group Thrombosis of the European Society of Cardiology (ESC) have created this consensus position paper to provide clear recommendations on the perioperative use of anti-platelet agents (specifically with semi-urgent and urgent surgery), strongly supporting a multidisciplinary approach to optimize the treatment of individual patients with coronary artery disease who need major cardiac and non-cardiac surgery. With planned surgery, drug eluting stents (DES) should not be used unless surgery can be delayed for ≥12 months after DES implantation. If surgery cannot be delayed, surgical revascularisation, bare-metal stents or pure balloon angioplasty should be considered. During ongoing antiplatelet therapy, elective surgery should be delayed for the recommended duration of treatment. In patients with semi-urgent surgery, the decision to prematurely stop one or both antiplatelet agents (at least 5 days pre-operatively) has to be taken after multidisciplinary consultation, evaluating the individual thrombotic and bleeding risk. Urgently needed surgery has to take place under full antiplatelet therapy despite the increased bleeding risk. A multidisciplinary approach for optimal antithrombotic and haemostatic patient management is thus mandatory.

Encapsulated, genetically engineered cells, secreting glucagon-like peptide-1 for the treatment of non-insulin-dependent diabetes mellitus.

Non-insulin-dependent, or type II, diabetes mellitus is characterized by a progressive impairment of glucose-induced insulin secretion by pancreatic beta cells and by a relative decreased sensitivity of target tissues to the action of this hormone. About one third of type II diabetic patients are treated with oral hypoglycemic agents to stimulate insulin secretion. These drugs however risk inducing hypoglycemia and, over time, lose their efficacy. An alternative treatment is the use of glucagon-like peptide-1 (GLP-1), a gut peptidic hormone with a strong insulinotropic activity. Its activity depends of the presence of normal blood glucose concentrations and therefore does not risk inducing hypoglycemia. GLP-1 can correct hyperglycemia in diabetic patients, even in those no longer responding to hypoglycemic agents. Because it is a peptide, GLP-1 must be administered by injection; this may prevent its wide therapeutic use. Here we propose to use cell lines genetically engineered to secrete a mutant form of GLP-1 which has a longer half-life in vivo but which is as potent as the wild-type peptide. The genetically engineered cells are then encapsulated in semi-permeable hollow fibers for implantation in diabetic hosts for constant, long-term, in situ delivery of the peptide. This approach may be a novel therapy for type II diabetes.

Pacemaker therapy in patients with neurally mediated syncope and documented asystole: Third International Study on Syncope of Uncertain Etiology (ISSUE-3): a randomized trial.

BACKGROUND: The efficacy of cardiac pacing for prevention of syncopal recurrences in patients with neurally mediated syncope is controversial. We wanted to determine whether pacing therapy reduces syncopal recurrences in patients with severe asystolic neurally mediated syncope. METHODS AND RESULTS: Double-blind, randomized placebo-controlled study conducted in 29 centers in the Third International Study on Syncope of Uncertain Etiology (ISSUE-3) trial. Patients were ≥40 years, had experienced ≥3 syncopal episodes in the previous 2 years. Initially, 511 patients, received an implantable loop recorder; 89 of these had documentation of syncope with ≥3 s asystole or ≥6 s asystole without syncope within 12 ± 10 months and met criteria for pacemaker implantation; 77 of 89 patients were randomly assigned to dual-chamber pacing with rate drop response or to sensing only. The data were analyzed on intention-to-treat principle. There was syncope recurrence during follow-up in 27 patients, 19 of whom had been assigned to pacemaker OFF and 8 to pacemaker ON. The 2-year estimated syncope recurrence rate was 57% (95% CI, 40-74) with pacemaker OFF and 25% (95% CI, 13-45) with pacemaker ON (log rank: P=0.039 at the threshold of statistical significance of 0.04). The risk of recurrence was reduced by 57% (95% CI, 4-81). Five patients had procedural complications: lead dislodgment in 4 requiring correction and subclavian vein thrombosis in 1 patient. CONCLUSIONS: Dual-chamber permanent pacing is effective in reducing recurrence of syncope in patients ≥40 years with severe asystolic neurally mediated syncope. The observed 32% absolute and 57% relative reduction in syncope recurrence support this invasive treatment for the relatively benign neurally mediated syncope. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00359203.

Critical single proximal left arterial descending coronary artery stenosis to mimic chronic myocardial ischemia: a new model induced by minimal invasive technology.

BACKGROUND/AIMS: The present report examines a new pig model for progressive induction of high-grade stenosis, for the study of chronic myocardial ischemia and the dynamics of collateral vessel growth. METHODS: Thirty-nine Landrace pigs were instrumented with a novel experimental stent (GVD stent) in the left anterior descending coronary artery. Eight animals underwent transthoracic echocardiography at rest and under low-dose dobutamine. Seven animals were examined by nuclear PET and SPECT analysis. Epi-, mid- and endocardial fibrosis and the numbers of arterial vessels were examined by histology. RESULTS: Functional analysis showed a significant decrease in global left ventricular ejection fraction (24.5 +/- 1.6%) 3 weeks after implantation. There was a trend to increased left ventricular ejection fraction after low-dose dobutamine stress (36.0 +/- 6.6%) and a significant improvement of the impaired regional anterior wall motion. PET and SPECT imaging documented chronic hibernation. Myocardial fibrosis increased significantly in the ischemic area with a gradient from epi- to endocardial. The number of arterial vessels in the ischemic area increased and coronary angiography showed abundant collateral vessels of Rentrop class 1. CONCLUSION: The presented experimental model mimics the clinical situation of chronic myocardial ischemia secondary to 1-vessel coronary disease.

Ex-PRESS R-50 miniature glaucoma implant insertion under the conjunctiva combined with cataract extraction

Rapport de synthèse : Le glaucome à angle ouvert est une neuropathie optique chronique progressive pour laquelle de nombreux traitements tant médicaux que chirurgicaux ont été proposés. La prise en charge chirurgicale s'articule principalement autour de deux chirurgies filtrantes, la trabéculectomie et la sclérectomie profonde avec implant de collagène. Cependant, les complications postopératoires de ces deux interventions étant relativement fréquentes, la recherche s'est orientée vers des traitements alternatifs dont la mise en place de micro-drains. Ces implants de drainage diminuent la pression intraoculaire en créant un court-circuit du flux d'humeur aqueuse de la chambre antérieure vers l'espace sous-conjonctival avec formation d'une bulle de filtration. L'implant Ex-PRESS R-50 est un implant miniature (2.5 mm de long pour 400 µm de diamètre) en acier inoxydable et biocompatible. La présente étude s'est proposée d'étudier l'efficacité et la sécurité de l'implant miniature Ex-Press R-50 lors d'une opération combinée cataracte-glaucome. Trente-cinq yeux de 35 patients (âge moyen: 75 ans) ont été inclus dans l'étude. Tous les patients ont bénéficié d'une opération de la cataracte par phacoemulsification et mise en place d'un implant de chambre postérieure suivie de l'implantation du micro-drain. Les pressions intraoculaires préopératoires et postopératoires, la meilleure acuité visuelle corrigée, le nombre de médicaments anti-glaucomateux ainsi que le type et le nombre de complications ont été évalués mensuellement puis tous les 6 mois pendant 4 ans. Le succès total a été défini par une pression postopératoire finale inférieure à 18mmHg sans traitement médical associé, le succès partiel par une pression postopératoire finale inférieure à 18mmHg avec ou sans traitement médical associé.. Le suivi moyen a été de 36.9 mois avec une baisse de la pression intraoculaire significative d'environ 25%. Une augmentation de l'acuité visuelle a été observée après l'opération de la cataracte et le nombre de médicaments anti-glaucomateux a été réduit de 57%. Dix patients ont bénéficié d'un traitement supplémentaire de la bulle de filtration par injection d'anti-métabolite (mitomycine C). Nous avons observé 8 complications majeures (4 érosions conjonctivales et 4 obstructions de l'orifice interne du micro-drain), toutes suivies de l'ablation de l'implant et de la réalisation d'une chirurgie classique du glaucome. En se basant sur les courbes de Kaplan-Meier à 48 mois, le taux de succès total était de 32.7% et le succès partiel de 53.7%. Nous pouvons conclure suite à ce travail que l'implant miniature Ex-PRESS R-50 est associé à un nombre trop élevé de complications, même si les cas non compliqués ont bénéficié d'une baisse significative de la pression intraoculaire. La modification de l'architecture du micro-drain ainsi que de la technique chirurgicale devrait augmenter le taux de succès.

Détermination de l'antigène HLA-G soluble dans le liquide folliculaire et dans le milieu de culture d'embryons comme indicateur du succès d'un traitement par FIV-ICSI [Soluble human leukocyte antigen-G (sHLA-G) in follicular fluid and embryo culture medium and its impact on pregnancy prediction in IVF-ICSI treatment]

In IVF around 70% of embryos fail to implant. Often more than one embryo is transferred in order to enhance the chances of pregnancy, but this is at the price of an increased multiple pregnancy risk. In the aim to increase the success rate with a single embryo, research projects on prognostic factors of embryo viability have been initiated, but no marker has found a routine clinical application to date. Effects of soluble human leukocyte antigen-G (sHLA-G) on both NK cell activity and on Th1/Th2 cytokine balance suggest a role in the embryo implantation process, but the relevance of sHLA-G measurements in embryo culture medium and in follicular fluid (FF) are inconsistent to date. In this study, we have investigated the potential of sHLA-G in predicting the achievement of a pregnancy after IVF-ICSI in a large number of patients (n = 221). sHLA-G was determined in media and in FF by ELISA. In both FF and embryo medium, no significant differences in sHLA-G concentrations were observed between the groups "pregnancy" and "implantation failure", or between the groups "ongoing" versus "miscarried pregnancies". Our results do not favour routine sHLA-G determinations in the FF nor in embryo conditioned media, with the current assay technology available.

Prospective randomized study of two cryopreservation policies avoiding embryo selection: the pronucleate stage leads to a higher cumulative delivery rate than the early cleavage stage.

OBJECTIVE: To compare the cumulative live birth rates obtained after cryopreservation of either pronucleate (PN) zygotes or early-cleavage (EC) embryos. DESIGN: Prospective randomized study. SETTING: University hospital. PATIENT(S): Three hundred eighty-two patients, involved in an IVF/ICSI program from January 1993 to December 1995, who had their supernumerary embryos cryopreserved either at the PN (group I) or EC (group II) stage. For 89 patients, cryopreservation of EC embryos was canceled because of poor embryo development (group III). Frozen-thawed embryo transfers performed up to December 1998 were considered. MAIN OUTCOME MEASURE(S): Age, oocytes, zygotes, cryopreserved and transferred embryos, damage after thawing, cumulative embryo scores, implantation, and cumulative live birth rates. RESULT(S): The clinical pregnancy and live birth rates were similar in all groups after fresh embryo transfers. Significantly higher implantation (10.5% vs. 5.9%) and pregnancy rates (19.5% vs. 10.9%; P< or = .02 per transfer after cryopreserved embryo transfers were obtained in group I versus group II, leading to higher cumulative pregnancy (55.5% vs. 38.6%; P < or = .002 and live birth rates (46.9% vs. 27.7%; P< or = .0001.Conclusion(s): The transfer of a maximum of three unselected embryos and freezing of all supernumerary PN zygotes can be safely done with significantly higher cumulative pregnancy chances than cryopreserving at a later EC stage.

What influence do anticoagulants have on oral implant therapy? A systematic review.

OBJECTIVES: This systematic review aims to assess the risks (both thromboembolic and bleeding) of an oral anticoagulation therapy (OAT) patient undergoing implant therapy and to provide a management protocol to patients under OAT undergoing implant therapy. MATERIAL AND METHODS: Medline, Cochrane Data Base of Systematic Reviews, the Cochrane Central Register of Controlled Trials and EMBASE (from 1980 to December 2008) were searched for English-language articles published between 1966 and 2008. This search was completed by a hand research accessing the references cited in all identified publications. RESULTS: Nineteen studies were identified reporting outcomes after oral surgery procedures (mostly dental extractions in patients on OAT following different management protocols and haemostatic therapies). Five studies were randomized-controlled trials (RCTs), 11 were controlled clinical trials (CCTs) and three were prospective case series. The OAT management strategies as well as the protocols during and after surgery were different. This heterogeneity prevented any possible data aggregation and synthesis. The results from these studies are very homogeneous, reporting minor bleeding in very few patients, without a significant difference between the OAT patients who continue with the vitamin K antagonists vs. the patients who stopped this medication before surgery. These post-operative bleeding events were controlled only with local haemostatic measures: tranexamic acid mouthwashes, gelatine sponges and cellulose gauzes's application were effective. Post-operative bleeding did not correlate with the international normalised ratio (INR) status. In none of the studies was a thromboembolic event reported. CONCLUSIONS: OAT patients (INR 2-4) who do not discontinue the AC medication do not have a significantly higher risk of post-operative bleeding than non-OAT patients and they also do not have a higher risk of post-operative bleeding than OAT patients who discontinue the medication. In patients with OAT (INR 2-4) without discontinuation, topical haemostatic agents were effective in preventing post-operative bleeding. OAT discontinuation is not recommended for minor oral surgery, such as single tooth extraction or implant placement, provided that this does not involve autogenous bone grafts, extensive flaps or osteotomy preparations extending outside the bony envelope. Evidence does not support that dental implant placement in patients on OAT is contraindicated.

Vancomycin exposure from active calcium sulfate bone filler

Objective: Bone cements and substitutes are commonly used in surgery to deliver antibiotics locally. The objective of this study was to assess the systemic absorption and disposition of vancomycin in patients treated with active calcium sulfate bone filler and to predict systemic concentrations under various conditions. Method: 277 blood samples were taken from 42 patients receiving vancomycin in bone cement during surgery. Blood samples were collected from 3h to 10 days after implantation. Vancomycin was measured by immunoenzymatic assay. Population pharmacokinetic (PK) analysis was performed using NONMEM to assess average estimates and variability of PK parameters. Based on the final model, simulations with various doses and renal function levels were performed. Results: The patients were 64 ± 20 years old, their body weight was 81 ± 22 kg and Cockcroft-Gault creatinine clearance (CLcr) 98 ± 55 mL/min. Vancomycin doses ranged from 200 mg to 6000 mg and implantation sites were hip (n=16), tibia (10) or others (16). Concentration profiles remained low and consistent with absorption rate-limited first-order release, while showing prominent variability. Mean clearance (CL) was 3.87 L/h (CV 35%), absorption rate constant (ka) 0.004 h-1 (66%) and volume of distribution (V) 9.5 L. Simulations with up to 8000 mg vancomycin implant showed systemic concentrations exceeding 20 mg/L for 3.5 days in 43% of the patients with CLcr 15 mL/min, whereas 7% of the patients with normal renal function had a concentration above 20 mg/L for 1.1 days. Subtherapeutic concentrations (0.4-4 mg/L) were predicted during a median of 22 days in patients with normal renal function and 4000 mg vancomycin implant, with limited influence of dose or renal function. Conclusion: Vancomycin-laden calcium sulfate implant does not raise toxicity concern. Selection of resistant bacteria, such as Enterococcus and Staphylococcus species, might however be a concern, as simulations show persistent subtherapeutic systemic concentrations during 3 to 4 weeks in these patients.

Qualité de vie avant et 6 mois après angioplastie coronaire transluminale percutanée

Contexte: Le traitement de l'angine de poitrine par angioplastie coronaire transluminale percutanée (PTCA) est efficace et peu invasif, mais son impact sur la qualité de vie des patients a été relativement peu étudié avec des questionnaires spécifiques. Méthode: Durant 6 mois, tous les patients souffrant d'une angine de poitrine pour qui une PTCA élective était envisagée, et qui étaient disponibles pour un suivi à 6 mois ont été inclus dans l'étude. Le questionnaire spécifique «Seattle Angina Questionnaire» (SAQ) a été utilisé le jour avant et 6 mois après la procédure. La décision d'implanter un stent était laissée au cardiologue au moment de la procédure. Résultats: 112 patients ont été initialement inclus. Trente-neuf d'entre eux ont été traités avec une PTCA, et 62 avec une PTCA et l'implantation de stent. Il n'y avait pas de différence de sexe, d.âge, de sévérité de l'angine de poitrine, et de type de lésion coronaire entre les deux groupes. Un suivi à 6 mois a été possible pour 101 patients (90% de la cohorte initiale). La qualité de vie a été améliorée de façon spectaculaire dans 4 des 5 dimensions du SAQ (limites physiques, stabilité de l'angor, fréquence de l'angor, perception de l'angor, p <0,001). Seule, la satisfaction avec le traitement était pire lors du suivi qu'avant l'intervention (p = 0,03), en particulier la satisfaction avec les explications reçues, la conviction que tous les moyens avaient été utilisés pour le traitement, et la satisfaction globale. L'implantation d'un stent n'a eu aucun impact sur ces résultats.

Retrograde ascending aortic dissection during or after thoracic aortic stent graft placement: insight from the European registry on endovascular aortic repair complications.

BACKGROUND: Single-center reports have identified retrograde ascending aortic dissection (rAAD) as a potentially lethal complication of thoracic endovascular aortic repair (TEVAR). METHODS AND RESULTS: Between 1995 and 2008, 28 centers participating in the European Registry on Endovascular Aortic Repair Complications reported a total of 63 rAAD cases (incidence, 1.33%; 95% CI, 0.75 to 2.40). Eighty-one percent of patients underwent TEVAR for acute (n=26, 54%) or chronic type B dissection (n=13, 27%). Stent grafts with proximal bare springs were used in majority of patients (83%). Only 7 (15%) patients had intraoperative rAAD, with the remaining occurring during the index hospitalization (n=10, 21%) and during follow-up (n=31, 64%). Presenting symptoms included acute chest pain (n=16, 33%), syncope (n=12, 25%), and sudden death (n=9, 19%) whereas one fourth of patients were asymptomatic (n=12, 25%). Most patients underwent emergency (n=25) or elective (n=5) surgical repair. Outcome was fatal in 20 of 48 patients (42%). Causes of rAAD included the stent graft itself (60%), manipulation of guide wires/sheaths (15%), and progression of underlying aortic disease (15%). CONCLUSIONS: The incidence of rAAD was low (1.33%) in the present analysis with high mortality (42%). Patients undergoing TEVAR for type B dissection appeared to be most prone for the occurrence of rAAD. This complication occurred not only during the index hospitalization but after discharge up to 1050 days after TEVAR. Importantly, the majority of rAAD cases were associated with the use of proximal bare spring stent grafts with direct evidence of stent graft-induced injury at surgery or necropsy in half of the patients.