Use of extended radial artery conduit for complete arterial revascularization
H. Ibrahim zdemir
Mohamed A. Soliman Hamad
Joost F. ter Woorst
Albert H.M. van Straten
Department of Cardiothoracic Surgery, Catharina Hospital
We have developed a new technique to elongate the radial artery (RA) with the distal segment of the left internal thoracic artery (LITA). The left anterior descending (LAD) artery is examined to define the site of the LITA-LAD anastomosis and the length of LITA required to perform the anastomosis. The distal segment of the LITA beyond this length is divided in order to elongate the RA. This extended conduit is long enough to perform complete arterial revascularization and to reach the ascending aorta for the proximal anastomosis. Between January 1998 and December 2010, 113 patients were operated on using this technique. There was no early mortality among the whole group. Two patients (1.8%) had perioperative myocardial infarction. Three patients (3.5%) had re-interventions. We conclude that this technique makes the optimal use of both arterial conduits and could be a valuable alternative option for patients who are selected for complete arterial revascularization.
In the last two decades, the radial artery (RA) has emerged as a
major alternative arterial conduit in preference to saphenous
vein grafts or when traditional grafts are unsuitable or
unavailable in coronary artery bypass grafting (CABG) [1, 2]. However, to
optimize the use of RA as a coronary bypass conduit, several
technical considerations have been emphasized . In an earlier
report , we showed that the best hospital outcome, using the
RA, is obtained when this conduit is proximally anastomosed to
the aorta. However, when both the right coronary artery and the
circumflex artery must be grafted, the RA is too short to reach
the aorta for the proximal anastomosis. In an attempt to offer
complete arterial revascularization, we have developed a
technique that makes the optimal use of both the left internal
thoracic artery (LITA) and the RA.
Radial artery extension technique
The LITA may be used as a pedicled graft with its adjacent veins
and pleura attached, or it may be skeletonized. The LITA should
be fully mobilized up to the left subclavian artery and down to
the epigastric bifurcation. The pleura is opened to allow the LITA
to lie anterior to the hilum of the left lung. The LITA is passed
through a window in the pericardium anterior to the phrenic
nerve. To gain the maximum length, the LITA may be
skeletonized by dividing the branches in the anterior intercostal space
close to the LITA. This technique preserves the collateral supply
to the sternum and may reduce the incidence of wound
complications . The LITA is preserved in a gauze soaked in arterial
vasodilation solution as reported earlier .
We performed a preoperative duplex sonographic
examination before harvesting the RA to confirm a functioning palmar
collateral circulation. Recently, we have been depending solely
on the preoperative clinical assessment of the ulnar collateral
blood supply using a modified Allens test . Harvesting the RA
has been described earlier. The side branches are then isolated
and either clipped or ligated with the harmonic scalpel.
We place a small cannula in the proximal end of the graft and
gently flush the entire graft with papaverine, being careful not to
over-distend the vessel. The entire RA pedicle graft is then
wrapped in papaverine-soaked gauze .
Before initiating the cardiopulmonary bypass, the left anterior
descending (LAD) artery is examined to define the site of the
LITALAD anastomosis and the length of LITA required to
perform the anastomosis. The distal segment of the LITA beyond
this length is divided in order to elongate the RA. This segment
could be as long as 810 cm if the LITA is optimally harvested.
This segment is anastomosed in an end-to-end fashion with the
RA, using a small-needled 7-0 polypropylene suture (Prolene,
Ethicon, Inc., Somerville, NJ, USA) (Fig. 1). In our experience, the
use of a Silber vasovasostomy clamp and a Portex Epidural
Catheter (Smiths Medical, Kent, UK) (Fig. 1) is helpful in
performing this anastomosis. This extended RALITA conduit is long
enough to supply all target vessels beyond the LAD (Fig. 2).
Finally, the extended conduit is anastomosed proximally to the
ascending aorta using 6-0 Prolene suture.
The Author 2012. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.
From January 1998 until December 2010, 113 patients were
operated on using this technique. Table 1 shows the baseline
characteristics of the patient population. The mean age was 55.1
0.5 years and the majority of the patients (90.3%) were male.
Fourteen patients (12.3%) had peripheral vascular disease and six
patients (5.3%) had a previous cerebro-vascular accident. The
mean number of distal anastomoses per patient was 3.2 0.8.
Table 2 shows the main early postoperative complications.
There was no early mortality among the whole group. Two
patients (1.8%) had perioperative myocardial infarction. Graft
occlusion was angiographically detected in four patients (3.5%);
two patients were treated with percutaneous coronary
intervention and two patients underwent redo CABG. No other
readmissions or recurrent angina have been registered.
The presented technique is an additional option to the existing
methods to offer a complete arterial revascularization. This
Data are expressed as numbers (%) or mean SD.
COPD: chronic obstructive pulmonary disease; CVA: cerebral vascular
accident; LVEF: left ventricular ejection fraction; Periop MI:
perioperative myocardial infarction; PVD: peripheral vascular disease.
Periop MI: perioperative MI; PCI: percutaneous coronary intervention;
CABG: coronary artery bypass grafting.
technique makes use of the entire LITA and entire RA without
operative mortality and with acceptable morbidity. The extended
conduit is long enough to reach the ascending aorta for the
proximal anastomosis. It has been shown that aortaRA grafting is
followed by less perioperative cardiac events than after ITARA
grafting . This is explained by possible initial higher flow rates in
grafts originating directly from the ascending aorta than in grafts
originating more peripherally . Composite grafts are relatively
technically difficult compared with conventional aorto-coronary RA
grafts. Another disadvantage of composite grafts is the reliance on
single inflow ( proximal left ITA) to supply all grafted territories .
Inspecting the coronary anatomy is important before deciding
to use the present technique. In the case of poor quality of the
distal coronary arteries or moderate proximal stenosis, the use of
RA is discarded to avoid spasm and competitive flow,
respectively. In addition, both the LITA and RA should be carefully
examined before planning to use either the extended RA conduit or
rather a composite Y-graft.
No technical problems have been posed by this technique as
the RALITA end-to-end anastomosis is less demanding than the
LITARA Y anastomosis. Another distinct advantage is that the
LITALAD anastomosis is made in the area where both arteries
have their maximal diameter. The ideal elastic and physiological
properties of the mid segment of the LITA are optimally used .
In a certain subset of patients, such as diabetic and obese
patients, the proposed technique may avoid the use of bilateral
internal thoracic arteries and its inherent risk of impaired sternal
healing [10, 11].
Conflict of interest: none declared.