A novel mother and child technique with a 4F inner catheter based on proper alignment of both catheters

A novel tapered guide extension catheter facilitated successful completion of complex percutaneous coronary intervention

BACKGROUND

Guide extension catheters (GEC) are widely applied to cope with insufficient backup support in complex percutaneous coronary intervention (PCI). In the study, we aim to evaluate the feasibility and safety with a novel 5-4F tapered GEC used in complex lesion.

METHODS

The single-center retrospective study enrolled a total of 615 patients, in whom the 5F or 5-4F Expressman GEC was used to facilitate PCI procedure. Demographic and procedural data were collected.

RESULTS

5F GEC was used in 295 patients and 5-4F tapered GEC in 320 patients. The average age was 63.6 ± 11.0 years and 81.6% of the patients were male. Severe calcification and chronic total occlusion (CTO) were the commonest indication for the GEC use. The 5-4F tapered GEC was frequently used in active greeting technique (AGT) during CTO intervention procedure than 5F GEC (6.1% vs. 13.1%, p < 0.001). The average depth of intubation was 41.5 ± 19.6 mm for the 5-4F tapered GEC and 24.4 ± 15.1 mm for 5F GEC (p < 0.001). The rate of successful device delivery with 5-4F GEC was higher than 5F GEC (95.6% vs. 98.4%, p = 0.037). Pressure damping with 5F GEC occurred frequently than 5-4F GEC (7.4% vs. 2.5%, p < 0.05). Similarly, the incidence of intraoperative hypotension was higher in 5F GEC than 5-4F GEC (4.7% vs.1.9%, p < 0.05).

CONCLUSIONS

The novel 5-4F tapered GEC was superior to the 5F GEC in facilitating successful completion of PCI in the majority of patients with complex lesions via transradial approach.

Finite element analysis for mechanics of guiding catheters in transfemoral intervention

BACKGROUND

During the percutaneous coronary intervention (PCI), the strong backup support of a guiding catheters is essential in reaching a target coronary lesion successfully. Nevertheless, it is difficult to explore the mechanics of a guiding catheter by analytical and experimental methods due to its complex deformation and interactions among guiding catheter, guide wire, and artery. In this study, the finite element method was used to analyze the backup support of a guiding catheter in transfemoral intervention (TFI).

METHODS

A finite element model was established in the light of geometric, mechanical properties of the guiding catheter and boundary con ditions. To validate the finite element model, an arterial tree model was constructed to measure the backup force of the guiding catheters in TFI. Then, the process of the guiding catheter disengaged from the ostium was analyzed.

RESULTS

The influencing rules of the geometric parameters of the guiding catheter on its backup support in TFI were obtained with the help of the finite element model. The result shows that the larger the outer diameter and wall thickness, the greater the backup support, 2.0 to 2.3 mm of the outer diameter was suggested. When designing a guiding catheter, it is wise to avoid α, the angle between the line and wall of the artery, being within 60° and 75° and it is a better choice if the contact length is between 5 and 12 mm.

CONCLUSIONS

This study sought to investigate the influencing rules of the geometric parameters of the guiding catheter on its backup support in transfemoral intervention. A finite element model for analyzing the backup support of a guiding catheter was validated by experiments. It indicated that the finite element method can analyze the varied laws of the guiding catheter with different geometric parameters.

"Combo" technique for the use of 7F guide catheter system during transradial approach

Even a regular lumen of radial artery may create difficulty in smooth negotiation and propagation of a 7F guide catheter while performing intervention through transradial approach. We describe successive five cases of a simple and innovative "Combo" technique, which helps relatively atraumatic tracking of a 7F guide catheter through the course of arm and chest vasculature for successful completion of procedure without significant damage and local pain.

Mother-child technique using a novel 4 Fr inner catheter

AIMS

The aim of this study was to assess the efficacy of the mother and child technique using a 4 Fr inner catheter in coronary angioplasty following the failure of conventional techniques.

METHODS AND RESULTS

We identified cases in which a 4 Fr inner catheter had been used to facilitate stent delivery following the failure of conventional techniques. Stent delivery using a 4 Fr inner catheter was performed in 30 cases and was successful in 29 cases. Nineteen cases for RCA, six cases for LAD and five cases for LCx were examined. Direct engagement of a 4 Fr inner catheter was accomplished in eight cases. In the remaining patients, deep engagement of a 4 Fr inner catheter was accomplished with the anchor technique and/or distal balloon deflation technique. Proximal stent delivery followed by distal stent deployment was performed in seven cases by using the distal balloon deflation technique in multiple stent deployment. There were no complications related to deep intubation of a 4 Fr inner catheter.

CONCLUSIONS

The use of a 4 Fr inner catheter is safe and highly effective for aiding stent delivery. The anchor technique and/or distal balloon deflation technique could be required for deep engagement of a 4 Fr inner catheter.

Efficacy of mother-child-grandchild technique: 4F and 5F inner catheters through mother guide catheter

Stent delivery failure to the distal lesion was still encountered even after the introduction of mother-child technique using a 5F or 4F child catheter. A 5F inner catheter with a length of 112cm, and a 4F inner catheter with a length of 122cm enabled a novel mother-child-grandchild technique. In in vitro experiments, not only was backup support increased, but superior trackability could also be obtained with the mother-child-grandchild technique, over the mother-child technique. We describe the clinical data using this novel mother-child-grandchild technique to deliver a stent to the severely bended and/or calcified distal lesion.