Effect of a Single Element Subcutaneous Array Electrode Added to a Transvenous Electrode Configuration on the Defibrillation Field and the Defibrillation Threshold

Even with the use of biphasic shocks, up to 5% of patients need an additional subcutaneous lead to obtain a defibrillation safety margin of at least 10 J. The number of patients requiring additional subcutaneous leads may even increase, because recent generation devices have a < 34 J maximum output in order to decrease their size. In 20 consecutive patients, a single element subcutaneous array lead was implanted in addition to a transvenous lead system consisting of a right ventricular (RV) and a vena cava superior lead using a single infraclavicular incision. The RV lead acted as the cathode; the subcutaneous lead and the lead in the subclavian vein acted as the anode. The biphasic defibrillation threshold was determined using a binary search protocol. Patients were randomized as to whether to start them with the transvenous lead configuration or the combination of the transvenous lead and the subcutaneous lead. In addition, a simplified assessment of the defibrillation field was performed by determining the interelectrode area for the transvenous lead only and the transvenous lead in combination with the subcutaneous lead from a biplane chest X ray. The intraoperative defibrillation threshold was reconfirmed after 1 week, after 3 months, and after 12 months. The mean defibrillation threshold with the additional subcutaneous lead was significantly (P = 0.0001) lower (5.7 ± 2.9 J) than for the transvenous lead system (9.5 ± 4.6 J). With the subcutaneous lead, the impedance of the high voltage circuit decreased from 48.9 ± 7.4 Ω to 39.2 ± 5.0 Ω. In the frontal plane, the interelectrode area increased by 11.3%± 5.5% (P < 0.0001) and in the lateral plane by 29.5%± 12.4% (P < 0.0001). The defibrillation threshold did not increase during follow-up. Complications with the subcutaneous electrode were not observed during a follow-up of 15.8 ± 2 months. The single finger array lead is useful in order to lower the defibrillation threshold and can be used in order to lower the defibrillation threshold.     

Treatment of Superficial Surgical Wounds after Removal of Seborrheic Keratoses: A Single-Blinded Randomized-Controlled Clinical Study

BACKGROUND: For the treatment of superficial surgical wounds, there are a number of options, including topical antibiotic ointments, dressings, and specialized wound care materials, such as hydrocolloid dressings. OBJECTIVE: To evaluate the wound-healing activity of a commercially available hydrocolloid wound dressing (Avery H2460, Avery Dennison, Turnhout, Belgium) in comparison with a control treatment (Fucidine cream with Cutiplast sterile dressing) in superficial wounds after surgical removal of seborrheic keratoses. METHODS: In a single-blinded, randomized, controlled trial, the hydrocolloid wound dressing (Avery H2460) was compared with healing by secondary intention as a control. Sixteen patients between 18 and 80 years of age with seborrheic keratoses were enrolled. Wound healing was evaluated after 7 and 10 days and then daily until complete closure of the wound area. In 7 of 16 patients, biopsies were taken after 14 days of reepithelization. RESULTS: The hydrocolloid wound dressing (Avery H2460) induced a significantly (p<.05) faster healing (median: 8.5 days) in comparison with the control treatment (median: 10 days). The histologic investigations showed no significant differences for the investigated parameters in both groups. CONCLUSION: The faster healing in comparison with the control treatment supports the use of the hydrocolloid wound dressing (Avery H2460) for the treatment of superficial surgical wounds.     

The determination of spontaneous megakaryocyte colony formation is an unequivocal test for discrimination between essential thrombocythaemia and reactive thrombocytosis

Summary. Spontaneous colony formation from bone marrow megakaryocyte progenitors (BMsCFU-Mk) was studied in 24 patients with essential thrombocythaemia (ET), 20 patients with reactive thrombocytosis (RT), 20 patients with polycthaemia rubra vera with thrombocytosis (PRVtr), 16 patients with chronic myeloid leukaemia with thrombocytosis (CMLtr) and 18 normal control subjects (C).
The culture medium which was used in the methylcellu-lose assay in vitro contained 30% of plasma from a single patient with hereditary haemochromatosis. Remarkable BMsCFU-Mk growth was recorded in all patients with ET but in none with RT or in C. BMs-CFU-Mk were present in 11/20 patients with PRVtr and 7/16 patients with CMLtr.
Spontaneous bone marrow erythroid progenitors (BMsBFU-E) were also determined in these patients. BMsBFU-E were found in 21/24 patients with ET and none in the patients with RT and C. All patients with PRVtr and one patient with CMLtr showed BMsBFU-E.
We conclude that our implementation of the in vitro methylcellulose assay allows the BMsCFU-Mk to be used as an unequivocal test for discrimination between ET and RT which has not been shown in previously published studies.
In addition, we present evidence that in 10 patients BMsCFU-Mk and/or BMsBFU-E growth in the test persisted after long-lasting haematological remission.     

A retrospective analysis of anesthesiologic complications in pediatric neurosurgery

Background and objective:  Different clinical and surgical factors can influence the occurrence of anesthesiologic complications in pediatric neurosurgery. Preoperative knowledge of these factors is of great importance in the application of safe anesthetics and a favorable surgical outcome. The objective was to establish the importance of clinical and surgical risk factors on the frequency of anesthesia complications in pediatric neurosurgery.
Data and method:  The research, from 1996 to 2000, involved 705 children, aged from <1 year to 15 years, who underwent surgery for elective neurosurgical pathology and severe head injuries. We analysed the influence that: age, the preoperative neurologic diagnosis, the urgency of the operation, additional disorders, the surgical position, and the duration of anesthesia had on the frequency of anesthesia complications. To test the statistical relevance and to confirm the hypothesis, the Pearson's chi-square test, Mann–Whitney U -test, and univariate and multivariate logistic regressions were used.
Results:  Anesthesia complications (cardiovascular, respiratory, air embolism, allergic reactions) were present in 68/705 (9.6%) patients. Their frequency was statistically greater in children for whom the surgery was >240 min, who were in the sitting position and when comorbidity was evident. Neither age nor the urgency of the operation or reoperation had any significant influence on the occurrence of anesthetic complications.
Conclusion:  The duration of anesthesia, the sitting position of the patient, and the presence of comorbidities significantly increase the risk of anesthesia complications in pediatric neurosurgery.     

DDD Pacemaker Implantation After Fontan-Type Operations

HEINEMANN, M.K., et al. : DDD Pacemaker Implantation After Fontan-Type Operations. Bradyarrhythmias developing after Fontan-type operations impair the function of the univentricular heart causing fatigue, headaches, ascites, and protein-losing enteropathy (PLE). Transvenous inaccessibility, requiring epicardial implantation, accounts for the reluctance to implant a pacemaker (PM). Between 1997 and 2000, 24 patients (mean age 9.5 years, range 6 months to 19 years) with Fontan-type operations received DDD pacing systems with atrial steroid-eluting stitch-on electrodes (mean capture threshold 1.9 V/0.5 ms, range 0.4–3.5 V) and ventricular screw-in electrodes (mean capture threshold 1.7 V/0.5 ms, range 0.1–3 V). The systems were implanted at the time of conversion from atrio- to cavopulmonary connections in 5 patients, at the time of a total cavopulmonary Fontan operation in 6, and 1–50 months thereafter (mean = 18) in 13 patients. A right ventricular anatomy was present in 13 (54%) of 24 of PM recipients, versus 35% of the overall population. After a mean follow-up of 3.5 years, the PM were functioning in DDD mode in 23 of the 24 patients. Length of hospital stay in the ten patients who underwent repeat sternotomy was 5 days, without procedure related complications. In three children a repeat sternotomy was avoided by implanting the atrial electrodes during the Fontan operation. All patients improved clinically, including resolution of PLE in four patients. Bradyarrhythmias may lead to significant morbidity after Fontan-type operations. Electrophysiological evaluation is advised at follow-up. The indication for implantation of a DDD pacemaker system should be liberal. Placing atrial electrodes during the Fontan operation, especially in the presence of a right ventricular anatomy, avoids repeat sternotomy. (PACE 2003; 26[Pt. II]:492–495)     

Absorbable Suture Technique: Solution to the Growth Problem in Pediatric Pacing with Endocardial Leads

Endocardial pacing system implantation has been performed in 15 children of mean age 37 months (ranging from 1 day to 89 months), Endocardial lead fixation was performed by means of slowly resorbable suture (Dexon) to allow spontaneous lead migration as the child grows. During a mean follow-up period of 61 months (range 17–108 months), none of the patients needed reintervention for correcting the lead length to allow growth.