Open chest after cardiac surgery; revisited

Abstract

We read with interest the article entitled ‘Outcomesof delayed sternal closure after complex aortic surgery’[1].We congratulate the authors for their excellent results.However, they only mentioned the mediastinitis and graftinfections as the outcomes although we expected someneurological, renal, gastrointestinal complications, septi-caemia and/or multiorgan failures.This is a retrospective study including a small number ofopen chest cases with the weaknesses of retrospectivestudies. In their study, Table 2 shows exploration in allsurvived patients {11} at least once, although the authorsmentioned exploration in 5 patients only.Mean left atrial and central venous pressures can reflect anew milieu after cardiac surgery produced by the factorsaffecting cardiac compression. Accordingly, it is wise to relyon mean left atrial or central venous pressure rather thanpatient profiles or operation-related factors such as cardi-opulmonary bypass time as predictors of open chestrequirement [2].Delayed sternal closure (DSC) is leaving the chest openedfor some time by delaying the closure of the sternum. Thereare two types of DSC.1. Primary delayed sternal closure (PDSC) is delaying thesternal closure either as a principal method or afterfailure of one or several trials of closure at the end of theoperation.2. Secondary delayed sternal closure (SDSC) is the closureof the sternum that was primarily closed at the end ofthe operation and was reopened during the early post-operative period [3].Didtheauthorshaveprimaryorsecondarydelayedsternalclosures and if so, did they find any differences betweenboth?To make it more simple and practical, a rise of centralvenous pressure of more than 2—5 mmHg is a predictor fordelayed sternal closure especially in higher risk cases such asCABG with ascending aortic surgery, CABG with valve surgeryand carotid endarterectomy, redo and emergent cases withlong cardiopulmonary bypass time, deep hypothermiccirculatory arrest, TAPVD, IAA, TGA, tetralogy of Fallot withabsent pulmonary valve, anomalous coronary anatomy, DKSand Norwood procedures [2—4].PDSC is to be decided even without performing a trial ofclosure in cases of (a) presence of important bleeding ofnonsurgicalcause;(b)massiveincreaseofthecardiacvolumedue to myocardial edema or dilatation or after theimplantation ofa homograft;and (c)needofhighventilatorypressures to maintain acceptable oxygen saturation.The predictors of failure of primary sternal closure areeither:1. Adropintheheartrate,arterialbloodoxygensaturation,central venous saturation and/or systemic arterialpressure.2. An increase in the heart rate, left atrial pressure, centralvenous pressure, pulmonary artery pressure and/orairway pressure.3. The appearance of arterial blood acidosis [3].Good sternal wound closure and sternal approximationare the most important factors that decrease the incidenceof mediastinitis. So the method of sternotomy closure,material and size of sutures can affect the incidence ofmediastinitis.According to Losanoff and colleagues, peristernal singlewires followed by alternative peristernal transsternalsingle wires are the best methods for the mechanicalstability of all the sternotomies. Peristernal figure of eight,Robicsek, multiple transsternal wires are less effectivemethods and pericostal figure of eight wires are the leasteffective [5].Although we believe that open chest management doesnot appear to increase the risk of infection (mediastinitis orgraft infections) during complex proximal aortic replace-ment, administration of vancomycin and ceftazidime for 5days post chest closure may be a good idea.