Reprint of: Thoracolumbar burst fractures associated with incomplete neurological deficit in patients under the age of 40: Is the posterior approach enough? Surgical treatment and results in a case series of 10 patients with a minimum follow-up of 2 years.

INTRODUCTION: Surgical management of thoracolumbar burst fractures is controversial. While the goals of surgical treatment are well accepted (i.e., fracture reduction and stabilization, neural elements decompression, and segmental angular deformity correction), the choice of the best surgical approach (i.e., posterior vs. anterior vs. combined approach) remains controversial. Several studies have debated the advantages of each surgical approach but there is no definitive evidence available to date, particularly in young adult patients. The aim of this study was to assess whether posterior approach alone can be a valid surgical treatment for patient under the age of 40 affected by thoracolumbar burst fractures and incomplete neurological deficits. MATERIAL AND METHODS: A total of 10 consecutive patients affected by thoracolumbar burst fractures associated with incomplete neurological deficits treated at our institution from January 2015 to February 2017 were included in our study. All patients were under the age of 40 at the time of injury and underwent decompression and stabilization using the posterior surgical approach alone. Demographics, clinical, and radiographic parameters were recorded preoperatively, postoperatively and at the latest available follow-up. The minimum follow-up was set at 2 years post-operatively. RESULTS: The mean operative time was 303.6 min (range, 138-486). Average blood loss was 756 mL (range, 440-2100). Nine out of ten patients returned to a normal neurological status after surgery while 1 patient showed some improvement but did not recover completely. Segmental kyphotic deformity improved from a mean of 21.8° before surgery to 14.8° at the time of the last follow-up. The anterior and posterior wall height of the fractured vertebra was restored with an average of 4 mm. The Visual Analogue Scale score reported an improvement from the mean preoperative value of 7.92 to 1.24 at the last follow-up; 8 out of 10 patients resumed physical activity while all of them returned to work. CONCLUSIONS: A single posterior surgical approach is an acceptable option in terms of clinical, radiological and functional outcomes at 2 years follow-up in patients under the age of 40 presenting with a thoracolumbar burst fracture and neurological deficit.

Thoracolumbar burst fractures associated with incomplete neurological deficit in patients under the age of 40: Is the posterior approach enough? Surgical treatment and results in a case series of 10 patients with a minimum follow-up of 2 years.

INTRODUCTION: Surgical management of thoracolumbar burst fractures is controversial. While the goals of surgical treatment are well accepted (i.e., fracture reduction and stabilization, neural elements decompression, and segmental angular deformity correction), the choice of the best surgical approach (i.e., posterior vs. anterior vs. combined approach) remains controversial. Several studies have debated the advantages of each surgical approach but there is no definitive evidence available to date, particularly in young adult patients. The aim of this study was to assess whether posterior approach alone can be a valid surgical treatment for patient under the age of 40 affected by thoracolumbar burst fractures and incomplete neurological deficits. MATERIAL AND METHODS: A total of 10 consecutive patients affected by thoracolumbar burst fractures associated with incomplete neurological deficits treated at our institution from January 2015 to February 2017 were included in our study. All patients were under the age of 40 at the time of injury and underwent decompression and stabilization using the posterior surgical approach alone. Demographics, clinical, and radiographic parameters were recorded preoperatively, postoperatively and at the latest available follow-up. The minimum follow-up was set at 2 years post-operatively. RESULTS: The mean operative time was 303.6 min (range, 138-486). Average blood loss was 756 mL (range, 440-2100). Nine out of ten patients returned to a normal neurological status after surgery while 1 patient showed some improvement but did not recover completely. Segmental kyphotic deformity improved from a mean of 21.8° before surgery to 14.8° at the time of the last follow-up. The anterior and posterior wall height of the fractured vertebra was restored with an average of 4 mm. The Visual Analogue Scale score reported an improvement from the mean preoperative value of 7.92 to 1.24 at the last follow-up; 8 out of 10 patients resumed physical activity while all of them returned to work. CONCLUSIONS: A single posterior surgical approach is an acceptable option in terms of clinical, radiological and functional outcomes at 2 years follow-up in patients under the age of 40 presenting with a thoracolumbar burst fracture and neurological deficit.

High frequency of contact allergy to gold in patients with endovascular coronary stents.

BACKGROUND: Stent implantation is an effective method for treatment of atherosclerotic disease. Factors predisposing to in-stent restenosis are still largely unknown. Contact allergy to metal ions eluted from the stent has been suggested to be a risk factor. OBJECTIVES: To explore whether there is a possible induction of contact allergy to metals used in stents among patients with a stainless steel stent containing nickel (Ni stent) and patients with a gold-plated stent (Au stent). METHODS: Adults (n = 484) treated with coronary stent implantation participated in the study with patch testing. The study design was retrospective and cross-sectional with no assessment of contact allergy before stenting. Age- and sex-matched patch-tested patients with dermatitis (n = 447) served as controls. RESULTS: Of Au-stented patients, 54 of 146 (37%) were allergic to gold compared with 85 of 447 (19%) controls (P < 0.001). Within the stented population there were no statistically significant differences in contact allergy to gold or nickel between Ni-stented and Au-stented patients. In multivariate models where other risk factors for contact allergy to gold were considered, the Au stent showed a trend towards statistical significance (odds ratio 1.43, 95% confidence interval 0.95-2.16; P = 0.09). CONCLUSIONS: As the frequency of contact allergy to gold is higher in stented patients independent of stent type it suggests a previous sensitization. However, several pieces of circumstantial evidence as well as statistical analysis indicate the possibility of sensitization in the coronary vessel by the Au stent. Ni stents and Au stents should not be ruled out as risk factors for induction of contact allergy to these metals.

Recording monophasic action potentials using a platinum-electrode ablation catheter.

AIMS: The monophasic action potential (MAP) is conventionally recorded using Ag-AgCl electrodes which are not suitable for delivering radiofrequency currents. To be able to use the sharp MAP upstroke for identifying the local activation, as a step towards the development of a MAP-guided catheter ablation technique, the possibility of recording MAP via platinum electrodes of an ordinary ablation catheter was explored. METHODS AND RESULTS: One hundred and forty-two MAP recordings from the endocardium were obtained via an ablation catheter in 40 patients undergoing electrophysiological study/catheter ablation. During sinus rhythm and pacing, 90% of the ventricular and 100% of the atrial MAPs had stable baselines. The amplitudes were 13 +/- 4.2 mV for ventricular and 2.4 +/- 0.8 mV for atrial MAPs. During mapping and ablation, MAPs and uni- and bipolar electrograms were recorded simultaneously using the same tip electrode in eight patients. The MAPs provided more distinct local activation than the electrograms. During 17 MAP recordings, additional MAPs were recorded simultaneously using an Ag-AgCl electrode catheter in the immediate vicinity of the ablation catheter. The MAPs taken with the ablation catheter had characteristics consistent with those taken with the Ag-AgCl catheter. CONCLUSIONS: (1) Platinum electrodes can be used for timely recording of MAPs in patients. (2) It is feasible to record MAPs and deliver radiofrequency currents via the same platinum-tip electrode. These findings suggest that MAP-guided catheter ablation is technically possible.

Signed value of monophasic action potential duration difference. A useful measure in evaluation of dispersion of repolarization in patients with ventricular arrhythmias.

AIMS: To evaluate the usefulness of the signed value of monophasic action potential duration difference in analysing the cause of dispersion of ventricular repolarization. METHODS AND RESULTS: Monophasic action potentials were simultaneously recorded from the right ventricular apex and outflow tract during programmed stimulation in 36 patients with ventricular arrhythmias. The time difference between the ends of repolarization on the two monophasic action potentials was used as a measure of the dispersion of ventricular repolarization, and the signed value of the monophasic action potential duration difference was used to specify the contributions of the activation time difference and the monophasic action potential duration difference to the dispersion of ventricular repolarization. During right ventricular pacing, single and double programmed stimulation and at the induction of ventricular arrhythmias, the dispersion of ventricular repolarization and the signed value of monophasic action potential duration difference were markedly greater in the 11 patients with polymorphic ventricular tachycardia/ventricular fibrillation induced than in the 13 patients with monomorphic ventricular tachycardia induced, and in the 10 patients with clinical polymorphic ventricular tachycardia/ventricular fibrillation/cardiac arrest than in the 12 patients with sustained monomorphic ventricular tachycardia. This disclosed that the increased dispersion of ventricular repolarization was caused by increases in both the activation time difference and the monophasic action potential duration difference in the former, but mainly by an increased activation time difference in the latter groups. CONCLUSION: The signed value of monophasic action potential duration difference can specify whether an increased dispersion of ventricular repolarization is caused by inhomogeneous repolarization, inhomogeneous conduction or both, and thereby it is useful in study of the mechanism of ventricular arrhythmias.

Dispersion of repolarization following double and triple programmed stimulation. A clinical study using the monophasic action potential recording technique.

To study the dispersion of ventricular repolarization following double and triple programmed stimulation and its correlation with the inducibility of ventricular arrhythmias, monophasic action potentials were simultaneously recorded from the right ventricular apex and outflow tract during programmed stimulation in 12 patients with ventricular arrhythmias and a normal QT interval. The time difference between the ends of the two monophasic action potentials were used as a measure of the dispersion of ventricular repolarization, which consists of the activation time difference and the monophasic action potential duration difference. During double and triple programmed stimulation, the dispersion of ventricular repolarization increased significantly with the shortening of the coupling interval but decreased slightly with the shortening of the preceding interval. The induction of the ventricular arrhythmias in these patients was invariably associated with a marked increase in the dispersion of ventricular repolarization. The maximal dispersion of ventricular repolarization was significantly larger in the seven patients with polymorphic ventricular tachycardia and/or ventricular flutter/fibrillation induced than in the four patients with monomorphic ventricular tachycardia induced. Analysis of the two components of the dispersion of ventricular repolarization revealed that the increased dispersion of ventricular repolarization was mainly caused by an increase in the activation time difference in the monomorphic ventricular tachycardia subgroup, and by increases in both the activation time difference and monophasic action potential duration difference in the polymorphic ventricular tachycardia/fibrillation subgroup. These findings suggest that increased dispersion of ventricular repolarization is one of the underlying mechanisms accounting for the myocardial vulnerability to ventricular arrhythmias and that repolarization disturbance is important for the genesis of polymorphic ventricular tachycardia/fibrillation.

Epiglottitis and torsade de pointes tachycardia.

Severe throat infection is not usually associated with a higher risk of paroxysmal attacks of torsade de pointes tachycardia. A patient is reported in whom epiglottitis was associated with the sudden development of cardiac syncope caused by an acquired adrenergic-dependent long QT syndrome and the development of ventricular arrhythmias.