Efficacy of 3-D-imaging in minimally-invasive screw fixation of proximal phalanx fractures: A cadaveric study.

The current study evaluated whether 3-D fluoroscopic imaging is capable of adequate visualisation, reduction and effective guidance of implant placement during a minimally-invasive screw-fixation (MISF) procedure in the treatment of proximal phalanx fractures. A comparison with conventional intraoperative 2-D imaging was performed in a cadaveric model. Conventional 2-D and 3-D imaging series were performed following the creation of proximal phalanx fractures, reduction and fixation, pre- and post-operatively. For both imaging modalities, attention was paid to A) correct reduction, B) screw-placement and, if present, C) intra-articular offset of fracture edges.The results revealed no related overall advantage of the 3-D imaging system over normal 2-D fluoroscopy at the proximal phalanx region. The authors conclude that, given the cost of 3-D imaging technology, as well as the increased time required for image acquisition, its routine use in the treatment of phalanx fracture cases is not justifiable at present.

Results of total aponeurectomy for Dupuytren's contracture in 61 patients: a retrospective clinical study.

INTRODUCTION: Many surgical techniques have been advocated to treat Dupuytren's contracture. Partial fasciectomy is often performed to treat the whole spectrum of Dupuytren's disease. METHOD: We have reviewed the effectiveness of total aponeurectomy performed on 61 patients [10 women and 51 men (male:female ratio 5.1:1) with a mean age of 63.0 (range 42-79 years) and a mean follow-up of 3.45 years (range 1.03-6.39 years)]. RESULTS: Post-operative complications including haematoma, seroma or necrosis were found in 13.8% of the patients. Recurrence of contracture occurred in 10.8% of the patients and 4.6% of the operated patients presented with a nerve lesion. Nerve irritation occurred in 6.2% of the patients. The mean DASH-score was 3.85 (range 0-52.5). Family pre-disposition was an important risk factor for Dupuytren's disease with 44.3% of patients having a positive family history. CONCLUSION: We suggest that total aponeurectomy is a promising alternative to partial fasciectomy with low risk for a recurrence and slightly increased risk for a nerve lesion.

Arthrodesis of the distal interphalangeal joint: description of a new technique and clinical follow-up at 2 years.

INTRODUCTION: Arthrodesis of the distal interphalangeal joint (DIPJ) is an accepted operative procedure to treat osteoarthritis, instability and joint deformity. There is a wide spectrum of recommended operative techniques including cerclage wires, headless screws, bio-resorbable pins and lag screws. Lag screw fixation remains one of the most accepted methods of fixation; however, problems can occur in particular subsidence of the screw head leading to loss of compression and prominence of the screw head in the finger tip necessitating removal. We describe here a new technique of DIPJ arthrodesis that avoids these problems. METHODS AND PATIENTS: The technique is described here in detail, and clinical results are given for 18 joints (17 patients) followed-up at a mean 24 months (range 6-44). RESULTS: Mean post-operative DASH score was 15. There were no cases of non-union; only four complications were seen, one case of nail growth disturbance and one of early screw breakage necessitating revision. Two infections necessitated early hardware removal although both arthodesis were united. CONCLUSION: The technique is simple and reliable giving consistent clinical results.

[Self-active physical thrombosis prophylaxis in the patients' bed with the Phlebostep: acceptance and measurement of venous blood flow in immobilized patients]. / Eigenaktive physikalische Thromboseprophylaxe im Patientenbett mit dem Phlebostep : Akzeptanz und venöse Flussmessung beim immobilisierten Patienten.

BACKGROUND: Despite the broad use of low molecular weight heparin, deep vein thrombosis is still a relevant risk for immobilized patients in orthopedic surgery. Patients can reduce this risk by active training exercises with a muscle pump. The aim of this study was to test the acceptance and effect of a self-developed training device to accelerate venous return as well as a technical optimization. The device was installed for in-patients in orthopedic and traumatology departments. PATIENTS AND METHODS: A simple pillow-like device was developed, which can be positioned against the foot end of the patient's bed (Phlebostep). The device gives a sound-based feedback to the patient while pushing actively against it with complete ankle flexion. A digital integrated counter device allows direct feedback to the physician and nursing staff at any time. Initial testing including duplex sonography for venous flow measurements were done on 10 orthopedic in-patients. Prior testing on 7 healthy volunteers was carried out to define the effect of various amounts of pressure on the Phlebostep on the venous blood flow. Additionally, a questionnaire on the general acceptance and user-friendliness was filled out by 84 patients who had used the Phlebostep. RESULTS: The optimal pressure force was defined as 35 mmHg for further measurements. The venous flow measurements in the 10 postoperative patients revealed an increased venous blood flow in the affected leg by an average of 99.9%. Analysis of the questionnaire from the 84 patients showed a high degree of acceptance. CONCLUSION: In addition to the technical feasibility, this study showed that use of the Phlebostep resulted on average in a doubling of venous return. The increase of venous flow offers an additional effective device for thrombosis prophylaxis through patient's own active movements and is clearly superior to the use of devices such as antithrombosis stockings alone. The Phlebostep found a high degree of acceptance with the patients.

Modified syringe design prevents plunger-related contamination--results of contamination and flow-rate tests.

The usual mechanism for syringe contamination is spread of micro-organisms along the inside of the barrel. Two or more full strokes of the plunger will inevitably transport a contaminant from the inside wall into the sterile compartment. We modified syringes by replacing the plunger with a modified version that has an additional central O-ring seal. Conventional and modified syringes were tested for their susceptibility to contamination using standard microbiological and radioisotope methods, and the flow-rate stability of the modified syringe design was assessed in a model with commercially available infusion pumps. Although conventional syringes consistently became contaminated with the second full excursion of the plunger, no contamination was observed in modified syringes, even after 100 aspiration/injection cycles. With respect to flow-rate stability, the new syringe design complies with DIN (German Institute for Standardization) standards.

Improved detection and analysis of sensed and paced events in dual chamber pacemakers with extended memory function. A prospective multicenter trial in 626 patients.

PATIENTS AND METHODS: This prospective study analyzed the incidence of atrial arrhythmias in a population of 626 patients in 173 medical centers of eleven European countries and Japan with indication for a dual chamber pacemaker system. The accuracy of the new Automatic Interpretation for Diagnosis Assistance (AIDA) program which is included in Chorus pacemakers was evaluated and the AIDA analysis was compared to and proven with Holter monitoring. Data stored in the pacemakers' memories for the first 24 hours (D1) were compared with simultaneously recorded 24-hour surface electrocardiograms, and data stored over the following 28 days (D28) were examined against reported intercurrent symptoms. RESULTS: At D1, atrial arrhythmias were detected by AIDA in 60 of 626 patients (12%), consisting of atrial fibrillation (n = 29), atrial flutter (n = 4), and miscellaneous arrhythmias (n = 17), and closely corroborated by Holter monitoring (sensitivity 93.7%, specificity 94.9%). At D28, 149 of 386 patients (49%) had had episodes of automatic mode switch prompted by atrial arrhythmias. Symptoms were reported by 81 patients (54%), 92 (62%) had no histories of atrial arrhythmias, and 57 patients (38%) were neither symptomatic nor had histories of atrial arrhythmias. An inverse relationship was found between the number of atrial paced events and the occurrence of atrial arrhythmias (p < 0.001). A history of atrial arrhythmias and older age were associated with a higher risk of atrial arrhythmias (p < 0.05). In contrast, gender, hypertension, concomitant heart disease, or type of atrial lead fixation system were not related with the occurrence of atrial arrhythmias. CONCLUSION: AIDA allowed to confirm, or disprove, the occurrence of atrial arrhythmias as a source of symptoms reported during long-term follow-up. It could also be used to examine the efficacy of antiarrhythmic therapy, and be of assistance when weighing the needs for anticoagulation in patients experiencing asymptomatic atrial arrhythmias.

[Pacemaker and defibrillator lead extraction techniques - literature review and own results]. / Verfahren zur Extraktion von transvenösen Herzschrittmacher- und Defibrillatorsonden : Literaturübersicht und eigene Ergebnisse.

In the past, the application of continuous traction used to be the alternative to open surgical removal of impacted pacemaker leads. Today's state-of-the-art methods for lead extraction follow the principles of traction (by locking stylets) and countertraction (by outer sheaths). Technical advances with respect to outer sheath design - including the use of lasers or bipolar electrocautery - led to a higher success rate, particularly as far as the removal of endocardial defibrillator leads is concerned. From 1997 to 1999, we treated 31 patients (pts) who required lead extraction more than 6 months after lead implantation. In 16 pts pacemaker leads and in 15 pts endocardial defibrillator leads had to be removed. All but one infected lead could be extracted using the "Cook-Byrd-Method" described here. Incompletely extracted leads were more common in the patient group without infection. This may be the result of different levels of "aggressiveness" when removing leads in infected and non-infected cases, and a reflection of the different risks. We report on the technical principles of lead removal. Published methods and results are reviewed and compared. The laser sheath, recently favored by some authors, are not necessarily quicker, better and safer. New electrosurgical dissection sheaths seem to be promising in one study with just a small sample size. The results of the EXCL study (Electrosurgical Extraction of Cardiac Leads) will provide us with new data. Complete lead removal is mandatory, especially in systemically infected pacemaker systems, while it remains most important to prevent harm to the individual patient. The "aggressiveness" of each procedure should be related to the potential risk. However, the costs associated with each method may not be neglected.

Interaction of the ACE D allele and the GNB3 825T allele in myocardial infarction.

In polygenetic disorders, such as ischemic heart disease, the investigation of gene-gene interactions rather than determination of single gene effects is crucial to better understand the contribution of genetic factors. The 825T allele of the G-protein ss(3)-subunit gene (GNB3) associated with enhanced G-protein signaling is a candidate to interact with the angiotensin-converting enzyme (ACE) deletion/insertion (D/I) polymorphism to increase the risk for myocardial infarction (MI). The ACE D:/I variant affects the renin-angiotensin system hormones that activate G-protein-coupled receptors. Genotyping at the ACE and GNB3 loci was performed on 585 patients with coronary artery disease with (n=270) or without (n=315) previous MI. Logistic regression analysis demonstrated a significant interaction between the ACE D: allele and the GNB3 825T allele (P<0.001). The odds ratio for MI, associated with the 825T allele, was not increased in the presence of the ACE II genotype (OR 0.5; P=0.09) but was significantly higher in 825T allele carriers with the ACE DI genotype (OR 1.9; P=0.01) and further increased in individuals with the ACE DD genotype (OR 2.4; P=0.02). The highest odds ratio was found in homozygous 825T allele carriers with the ACE DD genotype (OR 7.5; P=0.006). Our data suggest a significant interaction of the GNB3 825T allele with the ACE D allele in MI. These hypothesis-generating data may justify larger prospective studies.

Effects of defibrillator implantation testing on myocardial metabolism.

BACKGROUND: The effects of fibrillation/defibrillation episodes (FDEs) during defibrillator implantation on myocardial metabolism were investigated at various defibrillation energies in patients with different cardiac pathologies. METHODS: Myocardial lactate extraction (MLE) was examined during defibrillation threshold (DFT) testing in patients with either coronary artery disease (CAD, n = 20) or non-ischemic cardiomyopathy (CM, n = 10). Defibrillation pulses were released 15 seconds after induced fibrillation. A test cycle of four FDEs separated by 2-minute intervals was applied in each case. RESULTS: Mean MLE decreased significantly from 28 +/- 4% before FDEs to 8 +/- 5% immediately after all episodes in CAD patients, but recovered to 27 +/- 7% within 2 minutes even in patients with reduced left-ventricular function. In patients with CM mean MLE decreased markedly from 29 +/- 3% to -11 +/- 3% immediately after each FDE but increased to baseline (33 +/- 8%) within the recovery period. MLE changes were independent of defibrillation energy in all cases. CONCLUSIONS: Myocardial lactate production, suggesting cardiac ischemia, was observed in patients with CM, but not in patients with CAD. But recovery of myocardial lactate extraction was not faster in CAD patients, indicating that the fixed FDE cycle used was well tolerated by all patients.

[Surgical management of type III thoracic shotgun injury]. / Chirurgisches Management des thorakalen Schrotschusses Typ III.

Reporting the case of a short-range severe thoracic shotgun injury the differentiated management of this trauma is discussed. Indication for operative exploration under emergency conditions is hemorrhagic shock, perforation of esophagus/stomach and pericardial tamponade. Even under a toxicological point of view there is no indication for emergency revisions.

[Changes in heart surgical strategies: a word of caution]. / Herzchirurgische Strategien im Wandel: Ein Wort der Vorsicht.

The introduction of minimally invasive coronary artery bypass surgery has expanded the technical armementarium for operative treatment of coronary artery disease. Minimal access surgery using partial sternotomy or anterior intercostal minimal thoracotomy can be combined with videoscopic techniques or port-access-methods. Either atrio-aortal cannulation, femoro-femoral or jugular-femoral connections to the pump are possible for extracorporal circulation (ECC). Even endoluminar occlusion of the aorta and application of cardioplegia into the aortic root can be considered and applied. Extracorporal circulation has developed into a safe standardized method. As far as pathophysiology is concerned, the decision to use ECC or not is of much more importance than the grade of invasiveness. Fundamentally we therefore need to distinguish between minimally invasive methods with and without ECC. Video-assisted coronary surgery in hearts under hypothermia and fibrillation with ECC is also recommended occasionally. Minimally invasive coronary artery procedures on beating hearts without ECC have to be done in a stabilized and bloodless operative field to allow the construction of high standard anastomoses between bypass grafts and coronary arteries. In practice, silicon occluders, epicardial and myocardial suture occlusion and fixation, mechanical stabilization devices, and pharmacologic induction of bradycardia are used. In principle a skilled surgeon should be familiar with all these methods to select the most suitable solution for the special clinical problem. A final judgement about each method is not possible up to now. High patients numbers have to be recruited in the groups and subgroups due to low mortality (1%) and morbidity (5%), otherwise statistical significance of the results cannot be gained.

Atrial fibrillatory electrogram measurement allows atrial lead placement in patients who develop atrial fibrillation during permanent dual chamber pacemaker implantation.

The benefit of DDD(R) pacing is proven even in patients with intermittent atrial fibrillation. Atrial fibrillation developing during dual chamber pacemaker implantation creates a difficult problem. Maneuvers to reestablish a stable atrial rhythm often are required if atrial fibrillation sets in. This study was performed to determine if atrial lead placement can be performed with acceptable long-term results in the presence of atrial fibrillation. Twenty-one patients in whom atrial fibrillation developed during permanent pacemaker implantation were included in this study. In 12 patients, episodes of intermittent atrial fibrillation had been documented before the procedure. Screw-in leads were used in 15 patients and J-shaped passive fixation leads in 6 patients. All leads were bipolar. The intraoperative atrial fibrillation electrogram amplitudes ranged from 0.9 to 3.2 mV (mean 1.8 +/- 0.6 mV). One patient required lead revision due to a high atrial pacing threshold after conversion to SR. One patient remained in atrial fibrillation at 3-month follow-up. The other 20 patients converted to SR, 11 of whom had intermittent atrial fibrillation with successful mode switch activation. P wave amplitudes were 2.8 +/- .6 mV (range 1.4 to 4.0 mV) after conversion to SR. The mean atrial pacing threshold was 1.1 +/- 0.5 V (range 0.5 to 3.5 V). Placement of atrial leads in patients who develop atrial fibrillation during pacemaker implantation is feasible; fibrillatory electrogram amplitudes showed a good correlation with the atrial signal after conversion to an organized atrial rhythm (r = 0.698). Acceptable atrial pacing thresholds can be expected as well.

Myocardial lactate extraction during repeated fibrillation/defibrillation episodes in defibrillator implantation testing.

Intraoperative testing with several fibrillation/defibrillation episodes (FDEs) is routinely performed during defibrillator implantation. Testing is considered safe even in patients with severe cardiac impairment, provided the recovery timespans and number of FDEs are adapted to the individual patient. Myocardial lactate extraction (MLE) was examined in two testing protocols. In 30 patients with coronary artery disease defibrillator implantations were performed under intravenous anesthesia. A percutaneous catheter was positioned into the coronary sinus (CS) underfluoroscopy. Two groups were randomly formed: group A (n = 20, mean number of FDEs: 4.2/patient) with 2 minutes waiting time between FDEs, and group B (n = 10, mean number of FDEs 4.1/patients) with 10 minutes between FDEs. Defibrillation pulses were released 15 seconds after T wave shock induced fibrillation. To estimate MLE, arterial and CS blood samples were collected before and after each FDE. After the last FDE, samples were obtained after 5, 10, and up to 20 minutes. In group A, MLE fell from a baseline value of 29.6% +/- 3.6% before the FDEs to 7.8% +/- 5.4% immediately after the episodes. MLE recovered to 27.2% +/- 6.5% within 1 minute and overshot to 35.6% +/- 5.8% within 5 minutes. In group B, MLE decreased from 37.6% +/- 7.5% to 15.1% +/- 8.1% immediately after each FDE and rose to its original value (33.6 +/- 7.8) within the 5-minute recovery period. MLE decreased immediately after each FDE, and recovered within 1 minute even in poor left ventricular function. For full MLE recovery a 2-minute wait between episodes is sufficient, if the total number of FDEs does not exceed four.

Percutaneous dilatational tracheostomy--early results and long-term outcome of 326 critically ill patients.

OBJECTIVE: To analyze perioperative and postoperative complications and long-term sequelae following percutaneous dilatational tracheostomy (PDT). DESIGN: A prospective clinical study of patients undergoing PDT. SETTING: Seven intensive care units at a University hospital PATIENTS: 326 intensive care patients (202 male, 124 female; age: 11-95 years) with indications for tracheostomy. INTERVENTIONS: Using tracheoscopic guidance, 337 PDTs were performed according to Ciaglias' method. In 106 decannulated patients, tracheal narrowing was assessed by plain tracheal radiography. RESULTS: Two procedure-related deaths were seen (0.6%). Perioperative and postoperative complications occurred with 9.5% of the PDTs. One of 106 patients, who were followed-up for at least 6 months, showed a clinically relevant tracheal stenosis. Subclinical tracheal stenosis of at least 10% of the cross-sectioned area was recognized in 46 of 106 patients (43.4%). In the univariate analysis, the degree of stenosis was influenced by the age of the patient (p = 0.044), the duration of intubation prior to PDT (p = 0.042) and by the duration of cannulation (p = 0.006). These parameters had no statistical significance in a multiple regression model. CONCLUSION: When performed by experienced physicians, percutaneous dilatational tracheostomy under fiberoptic guidance is a safe method. The risks of early complications and of clinically relevant tracheal stenoses are low. Subclinical tracheal stenoses are found in about 40% of patients following PDT.

Intravascular ultrasound (IVUS) examination reverses therapeutic decision from percutaneous intervention to a surgical approach in patients with alterations of the left main stem.

Intravascular ultrasound (IVUS) represents a new method to assess vessel lumen and wall morphology. To prospectively evaluate the usefulness of IVUS for further therapeutic decisions in left main stem (LM) lesions with unclear angiographic definition, this study was launched. We studied 56 patients with significant stenosis of the LAD and/or LCX arteries and questionable LM morphology. 30-MHz IVUS catheters with 2.9 or 3.2 F outer diameters were used. A significant luminal reduction of the left main stem was defined as an area stenosis greater than 50% or a minimal luminal diameter smaller than 3 mm as determined by IVUS. 36 of 56 patients (61%) fulfilled these criteria. Additionally, 12 patients showed a ruptured plaque within the LM. 30 of these 36 patients were originally thought to be candidates for angioplasty. After positive IVUS 34 of these 36 patients were sent to surgery. No perioperative ischemic complications occurred. In angiographically unclear left main stem findings. IVUS establishes a definitive diagnosis. After IVUS confirmation of significant left main stem pathology operative management should be the preferred approach as compared to transluminal coronary interventions. However, prospective randomized studies are needed to define the most efficient approach.