Quantification of horseradish peroxidase delivery into the arterial wall in vivo as a model of local drug treatment: Comparison between a porous and a gel-coated balloon catheter

Purpose: To quantify horseradish peroxidase (HRP) delivery into the arterial wall, as a model of local drug delivery, and to compare two different percutaneous delivery balloons. Methods: Perforated and hydrophilic hydrogel-coated balloon catheters were used to deliver HRP in aqueous solution into the wall of porcine iliac arteries in vivo. HRP solutions of 1 mg/ml were used together with both perforated and hydrophilic hydrogel-coated balloon catheters and 40 mg/ml HRP solutions were used with the hydrogel-coated balloon only. The amount of HRP deposited in the arterial wall was then determined photospectrometrically. Results: Using the 1 mg/ml HRP solution, the hydrogel-coated balloon absorbed 0.047 mg HRP into the coating. Treatment with this balloon resulted in a mean vessel wall concentration of 7.4 μg HRP/g tissue ± 93% (standard deviation) (n = 7). Treatment with the hydrogel-coated balloon that had absorbed 1.88 mg HRP into the coating (using the 40 mg/ml HRP solution) led to a mean vessel wall concentration of 69.5 μg HRP/g tissue ± 74% (n = 7). Treatment with the perforated balloon using 1 mg/ml aqueous HRP solution led to a mean vessel wall concentration of 174 μg/g ± 81% (n = 7). Differences between the hydrogel-coated and perforated balloons (1 mg/g solutions of HRP) and between hydrogel-coated balloons (0.047 mg vs 1.88 mg absorbed into the balloon coating) were significant (p < 0.05; two-sided Wilcoxon test). Conclusions: The use of a perforated balloon catheter allowed the delivery of a higher total amount of HRP compared with the hydrogel-coated balloon, but at the cost of a higher systemic HRP application. To deliver 174 μg HRP per gram of vessel wall with the perforated balloon, 6.5 ± 1.5 mg HRP were lost into the arterial blood (delivery efficiency range = 0.2%–0.3%). With 0.047 mg HRP loaded into the coating of the hydrogel balloon, 7.4 μg HRP could be applied to 1 g of vessel wall (delivery efficiency 1.7%), and with 1.88 mg HRP loaded into the coating of the hydrogel balloon, 69.5 μg HRP could be applied per gram of vessel wall (delivery efficiency 0.6%).     

Asymptomatic pulmonary vein stenosis after cryoballoon catheter ablation of paroxysmal atrial fibrillation

Pulmonary vein (PV) isolation is an effective treatment option for symptomatic atrial fibrillation. PV stenosis is a well-recognized complication of radiofrequency energy application but has not been observed following cryoballoon ablation. Here, we report a case of asymptomatic PV stenosis associated with cryoballoon PV isolation, illustrating a risk that should be considered when applying this technique.     

Salutogenesis, globalization, and communication

Achieving successful communication in transcultural contexts means integrating emotional communication patterns into a global context. Professional, rational communication is characteristic of the cultural dimension, and emotions are characteristic of the direct, interpersonal dimension of human existence. Humans strive to achieve coherence in all dimensions of their lives; this goal is in the end the most essential aspect of psychophysical self-regulation. A major role in integrating emotional needs and cultural features in global coherence is played by the attractor 'global affinity'. The transitions from emotional coherence to cultural coherence, and likewise from cultural coherence to global coherence, can cause considerable insecurity as well as psychological problems, which previously went by the name 'adjustment disorders'. However, instead of pathologizing these processes, we should understand them in a salutogenic sense as challenges important for both individual and collective development. The development of more coherence is regulated by the neuropsychological approach and avoidance system. This system can be consciously fostered by directing our attention to the commonalities of all human beings. Such a global salutogenic orientation furthers both communication and creativity in teamwork. This article introduces a consequent salutogenic and evolutionary systemic view of transcultural communication and demonstrates its effectiveness in a number of case examples.     

Editor’s Recognition Award for Distinction in Reviewing 2010

Editorial

Editor’s Recognition Award for Distinction in Reviewing 2010     

Long-term results of surgery for urethral stricture: a statistical analysis

PURPOSE: We assessed the long-term results of surgery for urethral stricture by statistical methods using guidelines for survival analysis. MATERIALS AND METHODS: Of the 267 patients who underwent surgery for urethral strictures between March 1993 and December 1999, 238 (89%) were followed prospectively. The primary end point was success rate of urethroplasty. Secondary end points were variables that might influence success rates. Survival data were analyzed by the Kaplan-Meier method and Cox regression using guidelines for survival analysis. RESULTS: The success rate of all urethroplasties was 82% (95% CI 66 to 89) at 7.5 years. A 6.5-year success rate of 86% (95% CI 70 to 95) was achieved by flap, of 86% (95% CI 66 to 100) by anastomotic, of 79% (95% CI 64 to 94) by mesh graft and of 56% (95% CI 20 to 100) by graft urethroplasty. No significant difference was found among the surgical procedures using the log rank (p = 0.269) or Gehan-Wilcoxon (p = 0.259) test. Multivariate analysis showed an increased risk of failed urethroplasty in patients previously treated with urethral stents (HR 3.69, 95% CI 1.27 to 10.8) and by 2 or more urethrotomies (HR 2.25, 95% CI 1.05 to 4.8). CONCLUSIONS: Using standardized success criteria and statistical methods that applied guidelines for survival analysis conclusions were drawn. Excellent results are achievable by all forms of urethroplasty, justifying a more liberal indication for urethral reconstruction.