Empyema is typically unilateral, while bilateral empyema is an uncommon, life-threatening condition that can result from pneumonia, septic emboli, or mediastinitis . According to previous reports [2,3,4, 6], the characteristics of adult patients with bilateral empyema have much in common with those who have alcohol addiction, diabetes mellitus, a history of heavy smoking, poor nutritional status, and significant tooth decay. The conventional procedures for treatment of empyema with fistulae are direct suturing, superimposition of the pedicled muscle flap on the fistula, and plugging of the responsible bronchi with materials such as an endbronchial Watanabe spigot.
In the current case, consistent with previous reports, the patient had many complications and health problems such as uncontrolled diabetes mellitus, decayed teeth, poor nutritional status and could not walk at the time of admission. His poor general physical condition necessitated a less invasive initial surgery. At the first operation, the right S10 fistula was in a difficult location for suturing under thoracoscopy and relatively large for directly suturing. In addition, direct suturing would possibly have caused further air leakage because the lung tissue around the fistula appeared to be fragile. We considered using pedicled intercostal muscle flaps to close the right S10 fistula, however, the patient’s poor general condition precluded the use of excessive surgical interventions. Thus, we planned a 2-stage surgery in which the fistula would be addressed after his general condition had improved. By the time of the second operation, the right S10 fistula had actually decreased in size since the time of the first operation and lung tissue around the fistula showed some reduction of fragility, presumably owing to control of the infectious source and the patient’s improved general condition. This improvement in condition allowed for the successful closure of the S10 fistula using pedicled intercostal muscle flaps. The left S10 fistula was crater-shaped and deeply cavitied. Direct suturing would have been a less invasive approach but it is not suitable for closure of deep fistula while remaining airtight. Harvesting the free intercostal muscle flap did not require additional skin incision and the flap was quickly created with minimal invasiveness. In addition, it is easily deformable material in response to a fistula shape. To strengthen lung tissue around the fistula and to control the infectious source, we thought plugging the fistula with the free intercostal muscle flap may be effective. We had also considered the use of a pedicled intercostal muscle flap at a later stage in case the free intercostal muscle flap failed to close the left S10 fistula. However, we were able to successfully close the fistula using the free intercostal muscle flap, which plugged the fistula in an airtight manner and resulted in complete stoppage of the air leakage. For unwell and undernourished patients, this method has advantages in terms of its simplicity and being less invasive than open-window thoracostomy or pedicled omentum flap interposition. Furthermore, our 2-stage operation strategy, in which more invasive procedures were planed after the patient’s general condition had improved, succeeded in complete control of the air leakage. In our case, open-window thoracostomy would have been one of the potentially effective surgical strategies. Had open-window thoracostomy been selected in the right pleural cavity at the time of first operation, the time taken to control the infectious source in the right side would likely have been reduced. However, at the time of the first operation on the right side, the condition of the left pleural cavity was uncertain, as such there was a possibility that the left pleural cavity may also have required open-window thoracostomy and bilateral open-window thoracostomy carries an increased risk of respiratory failure. In our case of bilateral fistulae, successful closure of the right fistula was achieved in the second operation 14 days after the first operation without open-window thoracostomy. Therefore, free intercostal muscle flap can be a useful approach for initial surgery for bilateral empyema with fistula.
Although free muscle flap does not have a blood supply, several reports have suggested that the use of a free graft patch, such as pericardial fat, periosteum, or costal cartilage, could be effective for closing bronchopleural fistulae and stopping alveolar air leakage [7,8,9,10]. This is the first report of empyema-associated fistula resulting from ruptured lung abscess to be successfully treated with free intercostal muscle flap. Although the long-term viability of free intercostal muscle flaps has not yet been verified and the extrapolation of this strategy using free intercostal muscle flap needs more accumulation of cases, we found that covering the fistula with a free intercostal muscle flap in an airtight manner was effective.