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Heart, Lung and Circulation Case Reports 1592009;18:133–162

Value of Multislice CT Scan in Redo CardiacSurgery with Previous Lita Graft

Pankaj Saxena, MCh, DNB a,∗, Lisa Friedrich, MBBS a andRohan Vanden Driesen, FRANZCR b

Mark A.J. Newman, FRACS a

a Department of Cardiothoracic Surgery, Sir Charles Gairdner Hospital, Hospital Avenue, Nedlands, WA 6009, Australiab Department of Radiology, Sir Charles Gairdner Hospital, Nedlands, WA, Australia

Redo cardiac surgery is commonly performed in the current era. We describe a clinical scenario in a patient witha patent left internal thoracic artery to left anterior descending artery graft, requiring replacement of ascending aorticaneurysm with previous coronary artery bypass operation complicated by mediastinits. A pre-operative 64 slice computedtomographic scan helped us plan and perform replacement of ascending aorta safely.

(Heart, Lung and Circulation 2009;18:133–162)© 2008 Australasian Society of Cardiac and Thoracic Surgeons and the Cardiac Society of Australia and

New Zealand. Published by Elsevier Inc. All rights reserved.

Keywords. Redo cardiac surgery; LITA; Multi-slice CT scan; Coronary artery bypass surgery

A63-year-old grossly obese man with body mass index(BMI) of 36.3 was referred for surgical management

of an asymptomatic ascending aortic aneurysm measur-

Discussion

The reported incidence of injury to a patent LITA graft atthe time of reoperation is 5.3% even in experienced centres

ing 66 mm in diameter with an anatomically normal aortic

valve. He had previous coronary artery bypass surgery(CABG) with composite left internal thoracic artery (LITA)and radial artery graft anastomosed in an end to end fash-ion and used as sequential grafts to posterior descending(PDA) and obtuse marginal artery (OM) 3 years ago. Thisoperation was complicated by post-operative mediastini-tis requiring surgical debridement. A helical multi-slicecomputed tomographic (CT) coronary angiogram and aor-togram were performed as a part of pre-operative work up.This outlined the anatomical relationship in retrosternalarea and the exact location of LITA graft (Figs. 1 and 2).All the grafts as well as native coronary arteries werepatent.

Redo sternotomy was performed safely and cardiopul-monary bypass was used with femoral arterial and rightatrial cannulation. Systemic cooling was performed to25 ◦C. Aortic cross clamp was applied. Myocardium wasperfused with the patent LITA to avoid injury to the graft.This was supplemented with continuous perfusion of coldblood administered through retrograde route using a can-nula placed in coronary sinus. Replacement of ascendingaorta was performed with a woven Dacron graft. The

and is associated with 50% mortality.1 After resternotomyand initial dissection of heart, we found that the adhe-sions around the LITA graft were too dense to allow us toperform safe dissection and snaring of ITA graft.

Byrne et al.2 have described their approach to patientsundergoing mitral valve surgery in the setting of previ-ous CABG with patent LITA to LAD graft. They foundthat right thoracotomy with systemic hypothermia (20 ◦C)and fibrillatory arrest with an open LITA graft has acomparable outcome in terms of operative mortality andincidence of peri-operative myocardial infarction as com-pared to the conventional approach with redo-sternotomyand aortic cross clamping. We cooled our patient to25 ◦C and maintained perfusion via antegrade and ret-rograde route throughout the procedure. Post-operativelyour patient did not have any evidence of myocardial infarc-tion (MI).

As LITA graft was not located close to posterior tableof sternum and was lateral to retrosternal area, we knewthat it was safe to perform median sternotomy and do theinitial dissection of the heart safely. Moreover we knewbeforehand that there was a plane of dissection between

patient made an uneventful recovery and was discharged the sternum and the ascending aortic aneurysm.Gasparovic et al. in their experience with 33 patients

onsrig

home on post-operative day 6.

Received 20 October 2006; received in revised form 13 April2007; accepted 13 April 2007; available online 12 July 2007

∗ Corresponding author. Tel.: +61 8 93463333; fax: +61 8 93462344.E-mail address: drpankajsaxena@hotmail.com (P. Saxena).

© 2008 Australasian Society of Cardiac and Thoracic SurgeAustralia and New Zealand. Published by Elsevier Inc. All

found that the anatomical relations of sternum to retroster-nal mediastinal structures assessed with pre-operativechest X-ray and conventional angiography were incon-sistent in 85% patients in comparison to the informationobtained from 3-D volume rendered CT scan. Based onthis information, they modified their operative strategy in

and the Cardiac Society ofhts reserved.

1443-9506/04/$30.00doi:10.1016/j.hlc.2007.04.015

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160 Case Reports Heart, Lung and Circulation2009;18:133–162

Figure 1. CT scan demonstrates the location of LITA-radial arterycomposite graft.

Figure 2. Reconstructed CT image demonstrates anatomicalrelationships in the retrosternal area.

21% patients. There was no injury to patent LITA graft oraorta in this series.3

In another study,4 alteration in the technique of mediansternotomy, modification of cannulation site and myocar-dial protection strategies were performed in 40% of agroup of 15 patients undergoing various re-operative car-diac surgical procedures. In 2 of their patients, based onthe additional information, the operations were deferred,as the risk of surgical procedures was deemed too high.

In this patient, CT scanning was performed to delin-eate the aneurysm as well as to assess the spatial relationof coronary grafts, in order to perform a safe repeat ster-notomy in a high-risk situation. With a previous history ofmediastinitis, the aim was to define the anatomic relation-ship of the aneurysm and right ventricle to the sternum.The CT angiogram delineated the patency of all the graftsas well as the native coronary circulation. Hence this scanprovides additional information as compared to conven-tional angiography. We would recommend a multisliceCT scan in the pre-operative evaluation of a majority ofpatients undergoing repeat sternotomy. Additional infor-mation that can be obtained is the presence of calcificatheromatous disease in adult patients and this can havesignificant implications in altering the operative strat-egy.

The use of 64-slice CT scanning helped us in the plan-ning of this high-risk operation with a large ascending

aortic aneurysm with a patent LITA graft and denseintrapericardial adhesions due to previous cardiac surgerycomplicated by mediastinitis.

References

1. Gillinov M, Casselman FP, Lytle BW, Blackstone EH, ParsonsEM, Loop FD, Cosgrove DM. Injury to a patent left internalthoracic artery graft at coronary reoperation. Ann Thorac Surg1999;67(2):382–6.

2. Byrne JG, Karavas AN, Adams DH, Aklog L, Aranki SF, FilsoufiF, Cohn LH. The preferred approach for mitral valve surgeryafter CABG: right thoracotomy, hypothermia and avoidance ofLIMA-LAD graft. J Heart Valve Dis 2001;10(5):584–90.

3. Gasparovic H, Rybicki FJ, Millstine J, Unic D, Byrne JG, YucelK, Mihaljevic T. Three dimensional computed tomographicimaging in planning the surgical approach for redo cardiacsurgery after coronary revascularization. Eur J Cardiothorac Surg2005;28(2):244–9.

4. Aviram G, Sharony R, Kramer A, Nesher N, Loberman D,Ben-Gal Y, Graif M, Uretzky G, Mohr R. Modification ofsurgical planning based on cardiac multidetector computedtomography in reoperative heart surgery. Ann Thorac Surg2005;79:589–95.