Backup support of the mother-child technique: technical considerations for the size of the mother guiding catheter.

BACKGROUND: We previously proposed a technique called the "mother-child technique" to facilitate stent delivery for complex coronary lesions. This technique is applicable when the backup support of the guiding catheter is insufficient. In this study, we used an in vitro coronary artery tree model to determine the impact of the size of the mother guiding catheter on the backup support of the mother-child guiding system. METHODS: The backup support was measured for the 4-in-5, 4-in-6, 4-in-7, and 4-in-8 systems as well as for the 5-in-6, 5-in-7, and 5-in-8 systems. RESULTS: Advancement of the child catheter into the coronary artery tree model improved the backup support of the mother-child system. When a 4-Fr child catheter was advanced by 9 cm, the relative increase in the backup support was 174% in the 4-in-5 system; it was 203% in the 4-in-6, and 135% in the 4-in-7 system (P < 0.05 vs. the mother catheter alone). The relative increase with the 5-Fr child catheter was 289% in the 5-in-6 system, and 152% in the 5-in-7 system (P < 0.0001 vs. the mother catheter alone). However, the improvement in the backup support with 9-cm child catheter advancement did not reach statistical significance for either the 4-in-8 (115%) or the 5-in-8 (112%) system (P = NS). CONCLUSIONS: The relative increase in the backup support of the mother-child system was inversely related to the size of the mother guiding catheter. Thus, the mother-child technique may be most useful for PCIs in which a small guiding catheter is used, such as transradial coronary interventions.

Percutaneous coronary intervention using a novel 4-French coronary accessor.

BACKGROUND: Percutaneous coronary intervention (PCI) using a guiding catheter with small diameters may have a favorable impact on vascular access complications and patient morbidity. Here, we report the initial results of PCI using a 4-Fr coronary accessor. METHODS: A total of 31 patients underwent 4-Fr PCI. Exclusion criteria for 4-Fr PCI were (1) lesions associated with large side branches requiring wire protection or kissing balloon technique and (2) planned use of angioplasty devices which were not compatible with 4-Fr catheter. RESULTS: A total of 36 lesions, including 4 chronic total occlusions (CTO), were treated. Access sites included radial artery in 19 patients (61%), brachial artery in 8 (26%), and femoral artery in 4 (13%). Four-Fr PCI was successful in 34 of 36 lesions (94%) in 29 of 31 patients (94%). One of the two unsuccessful patients was a case of CTO, and the other a case of tortuous right coronary artery. In both, crossover to a 6-Fr PCI was necessary. Among successfully treated 34 lesions of the 29 patients, coronary stents were deployed in 30 lesions (88%). There were no stent dislodgements or inadequate contrast opacification. No access-site related complications including radial artery occlusion were observed. CONCLUSIONS: PCI with a 4-Fr coronary accessor is a viable alternative to the use of larger guide catheters. The advent of 4-Fr stent delivery system may afford a less invasive approach for the treatment of patients with coronary artery disease.