In Vitro and Human Studies of a 4F Double-Coaxial Technique (“Mother-Child” Configuration) to Facilitate Stent Implantation in Resistant Coronary Vessels

Guide extension proximal locking method: standardization of maximum backup force in percutaneous coronary intervention

We developed the smallest diameter guide-extension catheter (GUIDE PLUS® 5Fr) to enable a new technique, the guide-extension proximal locking method (GP-Lock), and assessed its efficacy in the present experimental and clinical study. Sufficient guide catheter backup is sometimes crucial for PCI. We developed the KIWAMI-Lock direct anchoring method to obtain the strongest backup force by locking a Kiwami® 4Fr child catheter (Terumo Corp. Tokyo, Japan) directly to the coronary artery by ballooning from outside the child catheter. However, this method is complicated due to the requirement for a child catheter. We compared the backup power of the GP-Lock method and other conventional methods in an experimental study and compared the procedural outcomes of 17 cases treated using the initial GP-Lock method with 17 cases using the recent KIWAMI-Lock method before GP-Lock. The GP-Lock method had the highest backup force among the methods examined (GP-Lock: 293.7 ± 10.2 g force (gf), KIWAMI-Lock: 270.4 ± 12.9 gf, side branch balloon anchoring technique: 182.7 ± 8.1 gf, respectively, P < 0.0001). The preparation time was significantly shorter for the GP-Lock group than the KIWAMI-Lock group (5.0 [4.0, 5.0] min vs. 11.0 [8.0, 13.0] min, respectively, P < 0.001). The GP-Lock method makes it possible to easily obtain the strongest backup force, which can overcome situations where devices cannot pass through, especially in complex PCI procedures.

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.

Efficacy and safety of a mother-child technique for recanalization of chronic central venous occlusive disease in hemodialysis patients

OBJECTIVE

There is no optimal treatment for central vein occlusive disease that remains a major contributor to vascular access impairment. This study aimed to review the outcomes of percutaneous treatment with a mother-child technique in the treatment of symptomatic central venous stenosis (CVS) and central venous occlusion (CVO) in patients on hemodialysis.

METHODS

Data were collected retrospectively and included all consecutive patients with CVS or CVO who were treated with percutaneous angioplasty and stenting. The occlusive lesions were crossed using the mother-child technique with an angiographic catheter-in-guiding catheter system.

RESULTS

A total of 36 patients with symptomatic CVS and 45 patients with total CVO were included. The average age and gender composition were similar between the two groups. Patients with CVO had higher prevalence of diabetic nephropathy than CVS (24.4% vs 5.6%; P < .05). Lesion success, device success, and procedural success were achieved in 36 (100%), 1 (100%), and 36 (100%) patients in the CVS group and in 43 (95.6%), 11 (100%), and 43 (95.6%) patients in the CVO group, respectively. There were no severe complications or procedure-related deaths in either group. During follow-up (median, 6 months), the primary patency rates were 89.7% (CVS) and 81.0% (CVO) at 6 months and were 54.2% (CVS) and 47.1% (CVO) at 12 months. The assisted primary patency rates were 100% (CVS) and 91.2% (CVO) at 6 and 12 months.

CONCLUSIONS

With extra backup support of the mother-child technique, percutaneous treatment provides an effective and safe method for recanalization of chronic venous occlusion in patients on hemodialysis.

Techniques to Overcome Difficulty in Device Deliverability to Lesion in Complex PCI

Percutaneous Coronary Intervention (PCI) has revolutionized the management of Coronary Artery Disease and has become the preferred modality of revascularization in a majority of cases. Nevertheless, situations are encountered frequently where device deliverability to coronary lesions entails technical difficulties due to varied anatomies and lesional complexities like tortuosity, calcifications, length of lesions and vessel morphology. While continuous technological refinements are occurring in PCI hardware armamentarium and stent designs, a number of techniques and their modifications and variations have evolved to increase the applicability of PCI to difficult lesions. The present article envisages a thorough review of all aspects of improving successful device deliverability in complex PCI with prominent emphasis on increasing the backup support of Guide Catheters which is the primary factor of success in difficult coronary lesions.

Guide catheter extension lock enables the strongest backup force during the antegrade approach in percutaneous coronary intervention

Sufficient guide catheter backup is crucial for successful percutaneous coronary intervention (PCI). We have developed a new technique for locking a small child catheter to the vessel wall by balloon dilatation outside the child catheter at the proximal site of the main branch. We call this the "guide catheter extension lock" ("Kiwami^® lock", Kiwami^® child catheter, Terumo Corp. Tokyo, Japan). The guide catheter extension lock backup force was evaluated in an experimental model, and we report a case of chronic total occlusion treated with PCI using this technique. The guide catheter backup force was measured using an artificial cardiac vessel model with a right coronary artery and side branch. We evaluated the backup forces of the guide catheter extension lock and other techniques using an 8Fr Judkins right guide catheter (child catheter: 45.0 ± 4.6 g force [gf]; a 7Fr delivery catheter (Guide-Liner^®, Vascular Solutions, Minneapolis MN, USA): 67.4 ± 14.4 gf; an anchoring balloon technique at the side branch: 98.3 ± 11.9 gf; and the guide catheter extension lock: 112.1 ± 13.0 gf). The guide catheter extension lock technique provided the strongest backup force. Our clinical experience shows that this technique is effective during PCI.

Diagnostic and Guide Catheter Selection and Manipulation for Radial Approach

Transradial catheterization and percutaneous coronary interventions have multiple advantages, including reduced bleeding risk, reduced length of stay and costs, and increased patient comfort. Transradial catheterization and interventions requires the acquisition of various additional skill sets including radial arterial puncture, the ability to navigate the upper extremity vasculature, and understanding catheter selection and coronary engagement technique. Although standard femoral catheter shapes perform adequately from the left or right radial approach for coronary angiography, for percutaneous coronary intervention guide catheter support is critical. This article summarizes some practical learning points pertaining to navigating the upper extremity vasculature, and understanding catheter selection and coronary engagement technique.

The novel 4.5F CoKatte catheter for stent delivery facilitation in complex coronary artery lesions

BACKGROUND

The mother and child technique with a deep-seated 4F Kiwami catheter has been reported to be effective for delivering stents to complex lesions.

OBJECTIVES

To assess the feasibility and efficacy of a novel 4.5F child catheter for deep insertion and stent deployment into the distal coronary artery for the treatment of complex lesions.

METHOD

We retrospectively evaluated 51 consecutive patients, who underwent percutaneous coronary intervention between January 2011 and December 2013, using a 4.5F CoKatte catheter after stent delivery failure using the conventional procedures. We evaluated the procedure success, need for an additional anchor balloon technique, and complications related to the deep insertion.

RESULTS

Stent delivery to the intended lesion was successful in all cases. For advancement and subsequent deep intubation of the catheter, 42 lesions required the additional anchor balloon technique. No complications, including proximal dissection, air embolism, and severe ischemia, were observed in relation to the deep insertion of the catheter.

CONCLUSION

Percutaneous coronary intervention with the novel 4.5F catheter is a safe and effective method, which can facilitate stent delivery to a complex coronary lesion.

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.

Comparison of frequency of radial artery occlusion after 4Fr versus 6Fr transradial coronary intervention (from the Novel Angioplasty USIng Coronary Accessor Trial)

The frequency of radial artery occlusion was compared between patients receiving 4Fr versus 6Fr transradial coronary interventions (TRIs) in an open-label randomized trial (ClinicalTrials.gov identifier: NCT00815997). The primary outcome measure was radial artery occlusion on the day after TRI. The secondary outcome measures were the procedural success, major advanced cardiac events, access site-related complications, procedural times, fluoroscopy times, and contrast dye usage. A total of 160 patients were included. The procedure was successful in 79 of 80 patients (99%) in both groups. Whereas the 4Fr group showed no access site-related complications, the 6Fr developed 5 (6%), including 3 radial artery occlusions and 2 bleedings (1 radial artery perforation and 1 massive hematoma; p = 0.02). Although the radial artery occlusion rate was lower in the 4Fr versus the 6Fr groups, the difference was not significant (0% vs 4%, p = 0.08). The mean hemostasis time was significantly shorter in the 4Fr than in the 6Fr groups (237 ± 105 vs 320 ± 238 minutes, p = 0.007). In conclusion, these findings suggest that 4Fr TRI may become a less invasive alternative to 6Fr TRI in treating coronary artery diseases.

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.

Deep seating of 5 Fr. guiding catheter across the stenosis with 5 in 7 method was effective for severely calcified lesion

A 57-year-old male with end stage renal disease underwent coronary angiography (CAG). The CAG revealed two vessel disease with severe calcification. A week after the percutaneous coronary intervention (PCI) to the left anterior descending coronary artery (LAD), we performed PCI to the right coronary artery (RCA). Because of the calcification, no devices could be crossed. We then performed 5 in 7 method using Heartrail ST01, and inserted it across the stenosis, with dilatation balloon at the distal RCA as anchoring. Finally we managed to implant two stents. We report that 5 in 7 method and deep seating of 5 Fr. guiding catheter were effective for the severely calcified lesion.

A case of intervention for gastroepiploic artery bypass graft anastomosis stenosis with using a 4 Fr guiding catheter

Since it was first used and reported in 1987, the gastropepiploic artery (GEA) has emerged as an effective third or isolated arterial conduit for complete bypass grafting or for use in cases of limited graft numbers or poor quality vein grafts. Percutaneous intervention on the GEA graft can pose technical challenges by virtue of its anatomy and the more common occurrence of the stenosis distally at their anastomosis with the coronary artery. Here we describe the clinical utility of a 4 Fr straight guiding catheter for treatment of stenosis in a GEA coronary bypass graft.

Percutaneous coronary intervention by retrograde approach for chronic total occlusion of the proximal left anterior descending artery via a gastroepiploic artery graft

Coronary arteries connecting to septal branch are often occluded in post-coronary artery bypass graft cases. A 70-year-old male had undergone CABG; radial artery graft to the LCX, and gastroepiploic artery (GEA) graft to the RCA. Coronary angiography revealed total occlusion in proximal LAD, while both graft vessels had good flow. Retrograde percutaneous coronary intervention (PCI) procedure from the septal channel via GEA graft to the RCA was performed for total occlusion of LAD. Despite the tortuous GEA, deep engagement with a 4-french guiding catheter ensured powerful back-up force. After retrograde wire crossing, two drug-eluting stents were implanted, successfully.

Circulation: Cardiovascular Interventions Editors' Picks

The following are highlights from the new series, Circulation: Cardiovascular Interventions Topic Review. This series will summarize the most important manuscripts, as selected by the editors, that have published in the Circulation portfolio. The objective of this new series is to provide a concise review of significant papers that are relevant to interventional cardiology. The studies included in this article represent the most noteworthy research in the area of coronary stent placement.