The often-cited Latin aphorism "Ubi pus, ibi evacua" suggests that clinicians should open infected cavities. We showed that the combination of traditional OWT with the new intrathoracic VAC therapy fulfilled the criteria of this old knowledge, especially in debilitated patients with complicated empyema.
In regards to VAC therapy for open wound management, this new technique is often discussed as a reserve treatment when there are no other options. In one VAC group reported by Palmen and colleagues , the OWT was delayed 58 ± 119 days after the diagnosis of the empyema. Once treatment commenced, the total duration of OWT with VAC therapy was 31 ± 19 days. In the present study, for comparison, patients with delayed OWT and VAC therapy left our hospital after 31 ± 14 days and one patient died. In patients with initial fenestration, however, the hospital stay was only 11.5 ± 3.5 days. This finding was consistent with Massera and colleagues , who concluded that immediate creation of OWT is a significant predictor of successful thoracostomy closure. We subscribed to this opinion and extended early OWT installation to combined VAC therapy. In our opinion, the alternative treatment of OWT and VAC therapy should be discussed as soon as possible, especially for postoperative or chronic pleural empyema and in patients with increased risk for impaired wound healing (e.g., diabetes, obesity, steroids).
The presence of BPF or remaining lung tissue is not a contraindication for VAC therapy. Groetzner and colleagues , as well as Palmen and colleagues , defined patients with BPF as not qualified for VAC therapy. This recommendation led to Aru and colleagues . closing all of the BPFs before application of the VAC system. The closure of a BPF is the best precondition of empyema treatment, but sometimes the second closure is not possible. We treated two BPF patients with VAC and in all the installation of vacuum was possible. In one patient with a one mm fistula, the BPF was sufficiently closed after VAC therapy. The other BPF, with a diameter of eight millimetres, could not be closed by VAC, which was not a problem in the VAC treatment. Future studies should investigate the diameter of BPF that can be closed by negative pressure in VAC therapy.
VAC therapy seems to have a beneficial effect on the re-expansion of the remaining lung in patients (Figure 2.). For example, two patients with respiratory insufficiency were quickly removed from their respirators after VAC therapy.
Similar to other reports [5, 8, 10, 11], we applied a maximum suction of -125 mmHg directly to the pulmonary tissue using the V.A.C. GranuFoams. Starting with a lower suction (-75 mmHg) was useful in patients with prior pneumonectomy. In addition, membranes for tissue protection were not necessary and no major complications related to vacuum-assisted management were observed.
The frequency and the location of intrathoracic VAC varies, as this part of the surgical treatment is not defined. For example, Palmen and colleagues . changed the system in the surgical ward without anaesthesia every 3rd to 5th day, or more depending on purulent secretion or increased infection. However, Aru and colleagues . performed all sponge changes under general anaesthesia. For comparison, our patients underwent two debridements and VAC changes in the operation room, and additional changes were performed every 3rd to 5th day in the ward.
In most cases, VAC therapy resulted in the rapid eradication of local infection. We therefore withdrew antibiotics when there were no signs of sepsis and the thoracic cavity became sterile (mean time of 16.3 days). However, the role of simultaneous antibiotics flushing (e.g., V.A.C. Instill) has not yet been investigated.
After treatment of sepsis and local control of the empyema, often with reduction of the pleural cavity, patients could be discharged to an outpatient service with initial daily wound care by specialized nurse technicians. It was occasionally useful to continue the VAC therapy in this ambulant sector with the aim of further reduction of the pleural cavity (in the present study, N = 3). Thoracic surgeons should perform this outpatient treatment weekly.
In follow-up visits, the indication for closure of the OWT should be periodically evaluated. We closed our OWT after a mean time of three months, but two patients rejected this procedure. For comparison, Matzi and colleagues . performed closure of the thoracic cavity after VAC therapy in all cases between the 9th and 48th day (mean of 22 days). Additionally, Groetzner and colleagues . used the VAC system as a bridge to reconstructive surgery and removed it after a mean period of 64 +/- 45 days (range of 7 to 134 days) in all patients. These patients underwent direct surgical wound closure, and complete healing without recurrence was achieved in 11/13 (85%) patients.
Data from the literature show that the interval between installation and closure of the OWT is considerable longer in patients without additional VAC therapy [8, 13]. The average duration of OWT without VAC therapy at the Maastricht University Medical Centre was 933 ± 1422 days . Maruyama and colleagues reported an OWT interval from 128 +/- 32, 1 to 365, 8 +/- 201 days, depending on indication . In our patients with VAC therapy the chest wall was closed after a mean time of three months (97.5 ± 66.5 days). In the non-VAC group of Palmen and colleagues . six of the eight patients could be discharged home. In only two of them the OWT was closed by muscular flap. Four patients died during follow-up because of OWT-related complications (massive bleeding n = 1, recurrent infections of the thoracic cavity n = 3).
The rate of successful empyema treatment and closure of OWT by reconstructive surgery is in our study as well as in other studies with VAC therapy [10, 12]. substantial higher in correlation to groups with only OWT treatment.
In our opinion, the closure of the OWT depends on the patient's individual situation (e.g., general condition of the patient, planned rehabilitation). As a final step, the closure of the chest guarantees full mobilisation and a good quality of life, with only a very low risk of recurrent infections.
4.1. Study Limitations
We were only able to recruit eight patients who had required an OWT and only five patients who had residual pulmonary parenchyma in the past year. Because of these small numbers of patients, this study is a series of case studies and not a randomised trial.