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Page 6 of 10 Idhrees et al. Vessel Plus 2020;4:23 I http://dx.doi.org/10.20517/2574-1209.2020.15

at least a period of one year. Leflunomide (20 mg/day), tacrolimus and cyclosporine A have been tried with
favourable outcome [33-36] . Vascular interventional procedures are better to be done during the inactive phase
[34]
of the disease with perioperative continuation of immunosuppression for desired results . Preoperative
[36]
course of steroids might reduce the vasculitic activity .
In has been suggested by some authors that in active TA, endoluminal stenting and rotational atherectomy
[37]
can be used to postpone surgery . Though long-term results do not favour percutaneous coronary
intervention (PCI) for TA, PCI can be performed in an emergency situation, patients who refuse CABG or
in high-risk individuals. With regard to MACE, CABG is superior to PCI despite medical therapy in TA
patients with CAD.

A meta-analysis revealed that restenosis occurred more often with PCI than with open surgical intervention
[38]
for coronary artery involvement . On a cohort of 75 patients who underwent revascularisation, a
recurrent restenosis was demonstrated in more than three-fourths (78%) of angioplasties and 36% of
[16]
surgical procedures . Very little exists in the literature with regard to PCI for CAD in TA patients, barring
a few anecdotal case reports and small case series. Vasculitis, accelerated atherosclerosis and blood flow
alteration due to structural changes in vessel wall lead to acute ischemic events in TA. TXB2 (thromboxane
B2) level and platelet aggregation is increased in patients with TA. Low doses of aspirin are safe and
useful in preventing acute events of ischemia in TA. Antiplatelet therapy in pre- and post-endovascular
procedures reduce restenosis occurrence in TA [33,39] .

Surgery in CAD
In contrast to atherosclerotic disease, the use of the internal mammary artery raises concerns even though
the TA patients are young. A study of 321 TA patients in Japan showed that the most common involved
[40]
artery was the left subclavian followed by the carotid artery and right subclavian . Thus, the long-term
benefit of using the internal mammary artery as a conduit rings a bell, while on the other hand, the use
[41]
of saphenous vein graft has been recommended . In a review by Amano and Suzuki, saphenous vein
[31]
grafts were used in 80% of patients . As TA is a progressive disease, there is intimal proliferation which
can cause stenosis of the proximal anastomosis of the vein graft on the ascending aorta. Few authors have
suggested replacing a segment of ascending aorta with a Dacron patch, to which the proximal anastomosis
[41]
of the vein graft can be performed instead of the native aorta . Though long-term results are unknown,
few authors have suggested the use of the free internal mammary artery and radial artery [42,43] . Late
[6]
coronary artery bypass grafting was insufficient in 10% of patients undergoing surgery .

Other options for coronary interventions are surgical angioplasty of the left main coronary artery and
[44]
transaortic coronary ostial endarterectomy . Surgical angioplasty can be performed using a piece of
autologous pericardium, glutaraldehyde-treated pericardium, saphenous vein graft or a patch from the
internal mammary artery. Transaortic coronary ostial endarterectomy was indicated in patients with
localized lesions at the coronary ostium. The stenotic portion of the coronary artery is held with a piece of
thread and resected piecemeal with a scalpel and later punched out with a 4-mm Aorta-Punch. Care has to
be taken, as excessive resection may lead to perforation, bleeding, or hematoma at the junction of the aorta
and the ostium of the coronary artery.

MYOCARDIUM IN TA
Myocardial failure in TA can be due to systemic arterial involvement, hypertension, acute or chronic AR,
[45]
and pulmonary vascular involvement in patients with TA . It was demonstrated that the natural killer
cells and T lymphocyte-mediated autoimmune cell injury can happen by releasing the cytotoxic factor and
[47]
[46]
perforin in the vessel wall . Takeda et al. postulated a similar mechanism of myocardial involvement
in certain patients with TA. An immunohistochemical study of the cardiac myocytes was also positive for