J Thorac Cardiovasc Surg 1995;109:594-595
© 1995 Mosby, Inc.
Right ventricular rupture after mediastinitis
Raymond Cartier, MD
Montreal Heart Institute,
Montreal, Quebec, Canada
Reply to the Editor:
Dr. Yellin's excellent report about his experience with postoperative mediastinitis management is interesting and contributes to our search for the best way to deal with this worrisome complication. In our report about the "open treatment" of postoperative mediastinitis, we reported a 15% incidence of right ventricular (RV) rupture that we attributed to overstretching of the RV adherent to a mobile sternum during patient coughing. Obviously, Yellin and his group did not encounter this problem, because they managed 124 cases of mediastinitis with no spontaneous rupture. They have to be congratulated for these excellent results. However, we believe their patient population was significantly different from ours.
Most of our patients who have postoperative mediastinitis are treated with mediastinal exploration, povidone-iodine "lavage," and direct surgical closure with a tubing system for continuous povidone-iodine irrigation. This irrigation is normally continued for 3 to 5 days. The open chest treatment is normally reserved for long-lasting infection, whereas the infectious status of the mediastinum does not allow primary closure. The decision is based on surgeon preference during surgical exploration. The time delay between the operation and the mediastinal reexploration is then longer in these particular cases. This may explain the higher risk of adherence between the RV and the sternum. Dr. Yellin, in his report, did not mention the delay between the initial operation and the mediastinal débridement, but it is possible that this delay was shorter than ours. In our patient population that had spontaneous RV rupture, the average delay was 24 days between the operation and the debridement. Another important point is the period of mechanical ventilation. If the patient is kept under mechanical ventilation up until the final chest reconstruction, the risk of spontaneous RV rupture is virtually eliminated. In our cases of RV rupture, the first debridement was always kept to a minimum. In one case, at least, the rupture happened 24 hours after wire removal, with no mediastinal debridement at all, right after the patient's extubation and the first cough effort. In this particular case, the mediastinitis was clinically diagnosed 3
weeks after the operation.
We believe, along with Dr Yellin, that the key to the treatment of this complication is to recognize, as soon as possible, the mediastinitis itself so that the appropriate treatment can be initiated. The idea of proceeding, as a bedside procedure, to the "dewirering" of the patients in the intensive care unit is attractive because it shortens the delay. However, one has to bear in mind that the following period is crucial. In cases of early infection when the delay between the operation and the infection is less than 10 days, early extubation is plausibly appropriate. However, for a longer delay, we believe that the patient should be kept intubated, sedated, and mechanically ventilated until the final reconstruction is carried out, generally 4 to 6 days later. Lately, this is how we have managed our mediastinal infections and we have not encountered any new cases of spontaneous RV rupture.
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