2288 CORRESPONDENCE Ann Thorac Surg2013;96:2283–90

MISCELLANEOUS

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Reduction of Sternal Infection in Off-pump CABGby Modified Pedicle HarvestingTo the Editor:

We read with interest the systematic review and meta-analysisby Deo and colleagues [1] on bilateral internal thoracic artery(BITA) harvest and its effects on the incidence of deep sternalwound infections (DSWIs) in patients with diabetes [1]. This re-view addressed the important clinical questions of whether BITAharvest increases the risk of DSWI in diabetics and whether therisk of DSWI is minimized by skeletonized approach. The au-thors have concluded that the excess risk of DSWI with BITA isattributable to the use of pedicled approach.

We have published the incidence of DSWI in our retrospectivecohort study of 3072 patients undergoing off-pump coronaryartery bypass grafting and receiving single and bilateral ITAs.There were 1211 diabetic patients (181 patients received BITAgrafts [group1] and 1030 received single ITA grafts [group 2]) and1861 non diabetic patients (161 patients received BITA grafts[group3] and 1700 patients received single ITA grafts [group 4]).There was no significant difference in the incidence of DSWIamong the groups: 0.55%, 0.48%, 0.62%, 0.82%, respectively(p ¼ 0.835). We used a modification of the pedicle BITA harvesttechnique with sparing of the communicating bifurcation of ITAto the chest wall and preservation of pericardiacophrenic arteryand sternal intercostal trunks [2]. The incidence of DSWI indiabetic patients who received BITA grafts was reduced from4% to 0.55% and was comparable to that of diabetic patientsreceiving single ITAs and nondiabetics receiving either BITA orsingle ITAs when the above modification of pedicle ITA harvesttechnique was used. This modified pedicle technique possiblypromotes the collateral circulation to the sternum and presternaltissues following BITA harvest and thereby reduces the incidenceof sternal wound infection. Although we have not prospectivelycompared the incidence of DSWI between the skeletonized ITAharvest group and the modified pedicle BITA harvest group, theincidence of DSWI in our BITA group is comparable to theincidence of DSWI reported by other investigators using

� 2013 by The Society of Thoracic SurgeonsPublished by Elsevier Inc

skeletonized harvest technique [3]. Moreover, the pedicle ITAharvest is associated with less frequent injury to the conduit andless duration for BITA harvest compared with skeletonized BITAharvest.

Lokeswara R Sajja, MD, FACSGopichand Mannam, FRCS (CT)

Division of Cardiothoracic Surgery, STAR HospitalsRoad no.10, Banjara HillsHyderabad, Indiae-mail: sajjalr@yahoo.com

References

1. Deo SV, Shah IK, Dunlay SM, et al. Bilateral internal thoracicartery harvest and deep sternal wound infection in diabeticpatients. Ann Thorac Surg 2013;95:862–9.

2. Sajja LR, Mannam G, Dandu SBR, Sompalli S. Reduction ofsternal wound infection in diabetic patients undergoing off-pump coronary artery bypass surgery and using modifiedpedicle bilateral internal thoracic artery harvest technique.J Thorac Cardiovasc Surg 2012;144:480–5.

3. Peterson MD, Borger MA, Rao V, et al. Skeletonization ofbilateral internal thoracic artery grafts lower the risk of sternalinfection in patients with diabetes. J Thorac Cardiovasc Surg2003;126:1314–9.

ReplyTo the Editor:

We thank Drs Sajja and Mannam [1] for their critical review andappreciation of our efforts [2]. Our metaanalysis essentiallycompared the incidence of deep sternal wound infection (DSWI)in diabetic patients undergoing single left internal thoracicartery and bilateral internal thoracic artery (BITA) harvest with asubgroup analysis focused on BITA harvest as a pedicled orskeletonized technique.Although a metaanalysis allows us to apply inverse variance

weighting to obtain statistically significant results from indeter-minate studies with small individual events rates, it limits us withthe availability of study-level data. The internal thoracic artery isharvested using two standard methods: either as a pedicle con-taining periarterial tissue and its vena comitantes or in a skele-tonized fashion with preservation of collateral branches and thevein attached to the chest wall. We chose to combine andcompare these two methods in our systematic review. Minorvariations in harvest technique are inevitable when combiningdata from multiple institutions or even from multiple surgeonswithin a single center. However, our results clearly demonstratethat, compared with the skeletonized technique, pedicled harvestis associated with a significantly higher incidence of DSWI. Webelieve that our results are more significant given recently pub-lished data underlining the advantage of BITA use for long-termsurvival [3]. Unfortunately, a recent multiinstitutional surveyfrom Canada demonstrated that BITA use is still low amongmany surgeons [4].We congratulate Dr. Sajja and colleagues for implementing

BITA use in 15% of their diabetic patients, and we appreciatetheir modified pedicled technique. Berdajs and colleagues [5]have demonstrated that the lower aspect of the sternum isundersupplied and potentially more vulnerable to infection.Hence, the preservation of the lower communicating bifurcationwould greatly improve sternal blood flow. Although the learningcurve and time taken for the skeletonized harvesting techniquemay be longer than for the pedicled technique, we believe that

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