Percutaneous pericardial access for electrophysiological studies in patients with prior cardiac surgery: approach and understanding the risks

The anti-adhesive effect of anti-VEGF agents in experimental models: A systematic review

Adhesions constitute a major problem in abdominal-pelvic and thoracic surgery with significant impact in the postoperative quality of life and healthcare services utilization. Adhesiogenesis is the result of increased fibrin formation, impaired fibrinolysis, angiogenesis, and fibrosis. Despite the recent advancements, the ideal anti-adhesive agent remains to be determined. To this end, we performed a comprehensive literature search in PubMed, EMBASE, and Scopus databases to identify studies investigating the antiadhesive role of anti-VEGF agents in peritoneal, pleural, and pericardial experimental adhesion models. Fifteen studies were eligible for inclusion with a total population of 602 animals (334 rats, 180 rabbits, and 88 mice). The majority of included studies (11/15) used bevacizumab, while three studies used other anti-VEGF antibodies and one study used an anti-VEGFR-antibody. A rat model was used in nine studies, while rabbit (n = 3) or mouse (n = 3) models were used less frequently. Eleven studies used peritoneal models, three studies used pleural models, and one study used a pericardial model. The scales (n = 12) and interval (Range: 1-42 days) used for the evaluation of adhesions varied between the studies. All studies demonstrated a significant decrease in adhesion scores between the anti-VEGF and control groups up to 42 days postprocedure. VEGF blockade resulted in decreased fibrosis in four out of five studies that used peritoneal models, while the effect on pleural models depended on the pleurodesis agent and was significant between 7 and 28 days. The effect of anti-VEGF agents on anastomosis integrity depends on the dose and the model that is used (inconclusive results).Current data support the anti-adhesive role of Anti-VEGF agents in all three serosal surfaces up to 6 weeks postprocedure. Further studies are needed to confirm the anti-adhesive role of anti-VEGF agents in pleural and pericardial adhesion experimental models and investigate any effect on anastomosis integrity in peritoneal models.

Hybrid Catheter-Based and Surgical Techniques for Ablation of Ventricular Arrhythmias

Catheter ablation is a rapidly expanding and evolving field. The advent of interventional techniques and advances in technology have allowed catheter ablation to supplant antiarrhythmic surgery for ventricular arrhythmia treatment. However, issues related to access and energy delivery limit the use of catheter ablation in some cases. Hybrid catheter-based and surgical techniques represent a novel approach to overcome these limitations. The hybrid technique combines the strengths and minimises the limitations of either catheter or surgical ablation alone. There is a growing body of evidence in the literature supporting the safety and efficacy of the hybrid surgical technique. This review aims to provide an overview of hybrid surgical-catheter ablation for ventricular arrhythmia.

The Future of Percutaneous Epicardial Interventions

The pericardial space provides a unique vantage point to access different cardiac structures for diagnosis and treatment of arrhythmias and other nonelectrophysiologic conditions, such as heart failure. There have been notable innovations to improve safety of percutaneous pericardial access and its use for various procedures. Percutaneous pericardial device therapies for pacing and defibrillation have been in development, success of which will be a significant advance in treatment of bradyarrhythmias, cardiac resynchronization therapy, and prevention of arrhythmic deaths. There is need for continued efforts in development and expansion of this technique and a systematic approach to monitor efficacy and safety outcomes.

Epicardial access for VT ablation: analysis of two different puncture techniques, incidence of adhesions and complication management

Introduction

Pericardial access for ablation of ventricular arrhythmias (VA) can be gained either by an anterior-oriented or inferior-oriented epicardial puncture under fluoroscopical guidance. We retrospectively sought to assess the safety of these two puncture techniques and the incidence of epicardial adhesions and introduce our algorithm for management of pericardial tamponade.

Methods and results

In 211 patients (61.4 ± 15.6 years, 179 males; 84.8%) 271 epicardial ablation procedures of VA were performed using either an anterior- or inferior-oriented approach for epicardial access. Puncture-related complications were systematically analyzed. Furthermore, the incidence of adhesions was evaluated during first and repeated procedures.

A total of 34/271 (12.5%) major complications occurred and 23/271 (8.5%) were directly related to epicardial puncture. The incidence of puncture-related major complications in the anterior and inferior group was 4/82 (4.9%) and 19/189 (10.1%), respectively. Pericardial tamponade was the most common major complication (15/271; 5.5%). Collateral damages of adjacent structures such as liver, colon, gastric vessels and coronary arteries occurred in 6/189 (3.2%) patients and only within the inferior epicardial access group. Adhesions were documented in 19/211 (9%) patients during the first procedure and in 47.1% if patients had 2 or more procedures involving epicardial access.

Conclusion

Anterior-oriented epicardial puncture shows an observed association to a reduced incidence of pericardial tamponades and overall puncture-related complications in epicardial ablation of VA. In cases of repeated epicardial access adhesions increase significantly and may lead to ablation failure.

Confirming pericardial access by using impedance measurements from a micropuncture needle

BACKGROUND

Pericardial access is complicated by two difficulties: confirming when the needle tip is in the pericardial space, and avoiding complications during access, such as inadvertently puncturing other organs. Conventional imaging tools are inadequate for addressing these difficulties, as they lack soft-tissue markers that could be used as guidance during access. A system that can both confirm access and avoid inadvertent organ injury is needed.

METHODS

A 21G micropuncture needle was modified to include two small electrodes at the needle tip. With continuous bioimpedance monitoring from the electrodes, the needle was used to access the pericardium in porcine models (n  =  4). The needle was also visualized in vivo by using an electroanatomical map (n  =  2). Bioimpedance data from different tissues were analyzed retrospectively.

RESULTS

Bioimpedance data collected from the subcutaneous space (992.8 ± 13.1 Ω), anterior mediastinum (972.2 ± 14.2 Ω), pericardial space (323.2 ± 17.1 Ω), mid-myocardium (349.7 ± 87.6 Ω), right ventricular cavity (235.0 ± 9.7 Ω), lung (1142.0 ± 172.0 Ω), liver (575.0 ± 52.6 Ω), and blood (177.5 ± 1.9 Ω) differed significantly by tissue type (P < .01). Phase data in the frequency domain correlated well with the needle being in the pericardial space. A simple threshold analysis effectively separated lung (threshold  =  1120.0 Ω) and blood (threshold  =  305.9 Ω) tissues from the other tissue types.

CONCLUSIONS

Continuous bioimpedance monitoring from a modified micropuncture needle during pericardial access can be used to clearly differentiate tissues. Combined with traditional imaging modalities, this system allows for confirming access to the pericardial space while avoiding inadvertent puncture of other organs, creating a safer and more efficient needle-access procedure.