Minimally invasive vacuum-assisted closure therapy in the management of complex pleural empyema

Abstract

OBJECTIVES

The pool of potential candidates for pleural empyema is expanding. In a previous technical report, we tested the feasibility of the minimally invasive insertion of a vacuum-assisted closure (Mini-VAC) system without the insertion of an open-window thoracostomy (OWT). In this study, we describe a consecutive case series of complex pleural empyemas that were managed by this Mini-VAC therapy.

METHODS

In this retrospective study, we investigated 6 patients with multimorbidity (Karnofsky index ≤50%) who were consecutively treated with Mini-VAC for a primary, postoperative or recurrent pleural empyema between January 2011 and February 2012.

RESULTS

Local control of the infection and control of sepsis were satisfactory in all 6 of the patients treated by Mini-VAC therapy. The suction used did not create any air leaks or bleeding from the lung or mediastinal structures. Mini-VAC therapy allowed a reduction of the empyema cavity and improved the re-expansion of the residual lung. Mini-VAC therapy resulted in a rapid eradication of the empyema. The chest wall was closed in all patients during the first hospital stay. All patients left the hospital in good health (Karnofsky index >70%) and with a non-infected pleural cavity at a mean of 22 ± 11 days after Mini-VAC installation. Pleural empyema was not detected in any of the 6 patients at the 3-month follow-up appointment.

CONCLUSIONS

The Mini-VAC procedure with the abdication of an OWT offers a rapid treatment for complex pleural empyema with minimal surgical effort and the opportunity for a primary closure of the empyema cavity.

INTRODUCTION

Paradoxically, the pool of potential candidates for pleural empyema is expanding as a result of increased life expectancy, increased numbers of therapy-resistant cases due to antibiotic abuse, improved survival of patients with malignant disease and extended operability criteria within and outside the scope of thoracic surgery [1]. The management of empyema requires control of the infection and sepsis by antibiotic therapy, evacuation of the pus from the pleural space and obliteration of the empyema cavity. Open thoracotomy and decortication are performed for organized empyema with lung entrapment (≥Stage III disease). However, decortication may be associated with considerable operative morbidity (e.g. blood loss, persistent air leak, transient worsening sepsis) and even mortality. If the patient is medically unstable with sepsis, the evacuation of pus and debridement can be managed by Eloesser or Clagett OWT [2, 3].

Since the introduction of vacuum-assisted closure (VAC) therapy for the treatment of acute or chronic severe wound infections, other indications have been introduced. The first reports of intrapleural VAC therapy were published in 2006 [4]. To date, some reports [5, 6] have demonstrated the advantages of VAC therapy in patients with complex empyema. In a previous technical report, we tested the feasibility of the minimally invasive insertion of the VAC system without the insertion of an OWT [7]. Here, we describe a consecutive case series of complex pleural empyema that were managed by Mini-VAC therapy without classical OWT.

PATIENTS AND METHODS

Study sample

In this retrospective study, we investigated 6 consecutive patients with multimorbidity (Karnofsky index ≤50%) who were treated for a primary, postoperative or recurrent pleural empyema between January 2011 and February 2012. The Ethics Commission at the Krankenhaus der Barmherzigen Brüder Regensburg approved the study.

Patient demographics

Six patients were managed without ♂classical OWT by the adjunct of an intrathoracic VAC dressing for severe pleural empyema. One patient presented with an early/acute pleural empyema (≤30 days), and two presented with very late/chronic postoperative pleural empyema (328 and 602 days) after primary thoracotomy. One patient underwent chemotherapy for Stage IV non-small-cell lung cancer (necrotizing) and developed a primary empyema. One empyema was caused by aortic rupture and consecutive haematothorax from heart surgery, and one patient developed empyema caused by Boerhaave syndrome. The patient series consisted of 5 men and 1 woman with a mean age of 54.3 (range 41–72 years). The patient demographics and lung pathologies are summarized in Table 1. Except for 1 patient (Patient no. 6), who first underwent conventional treatment consisting of a chest tube thoracostomy, we initially used Mini-VAC therapy for the treatment of the detected empyema. Independent of the time of empyema (acute or chronic), Staphylococcus, Streptococcus and anaerobic species were the most frequently isolated organisms. Additionally, Aspergillus fumigatus was found in 3 patients.

Table 1:

Demographics of patients

Patient number	P1	P2	P3	P4	P5	P6
Age/sex	43♂	72♂	38♀	41♂	68♂	64♂
Karnofsky index <50%	Yes	Yes	Yes	Yes	Yes	Yes
Comorbidity	Yes	Yes	Yes	Yes	Yes	Yes
Immunosuppression	No	Yes	Yes	No	No	Yes
Primary diagnosis	Aortic rupture-haematothorax	NSCLC Stage IV	Rheumatic disease	Boerhaave syndrome	NSCLC Stage IA	SCLC Stage IV
Initial surgery	Sternotomy	Lobectomy	Thoracoscopic wedge resection	Decortication	Thoracoscopic lobectomy	Chest tube drainage

P: patient: (N)SCLC: (non)-small-cell lung cancer.

Minimally invasive vacuum-assisted closure therapy

Because of the poor general condition of our patients and our desire not to perform an extensive surgical procedure such as complete decortication, we pursued the use of Mini-VAC therapy, as first described by Hofmann et al. [7]. After mini-thoracotomy (a 5- to 6-cm incision for the thoracotomy without a rib spreader), the ALEXIS^® (Applied Medical, Rancho Santa Margarita, CA, USA) retractor was positioned. After debridement, local decortication and flushing of the pleural space, the VAC sponges (black GranuFoam Standard Dressings [KCI Medical, Wiesbaden, Germany], 400–600 µm) were inserted through the Alexis^® retractor to fill the entire pleural cavity (Fig. 1). The level of suction was set to −75 mmHg from the start.

Figure 1:

Position of the ALEXIS^® retractor and the VAC sponge.

Dressing changes were performed under anaesthesia in the operating theatre, with a median of 2 changes and a range of 1 to 4 changes.

All patients were treated with broad-spectrum antibiotics. The spectrum was modified in some cases based on the microbiological results. Antibiotic therapy was stopped when a wound swab showed no further pathogenic bacteria colonization (mean antibiotic therapy duration: 10.1 days).

RESULTS

Indications and time of Mini-VAC therapy

The indication for Mini-VAC installation was acute sepsis in patients with a poor general condition, failed primary conservative intervention (tube insertion) or complications of primary surgery (Table 2). No patient had a detectable bronchopleural fistula (BPF). The median time between the initial surgery and Mini-VAC-Therapy was 26.5 (range 4–602 days).

Table 2:

VAC and outcomes

Patient	P1	P2	P3	P4	P5	P6
Indication of Mini-VAC	Postoperative empyema	Sepsis empyema	Sepsis empyema	Postoperative empyema	Postoperative empyema	Primary empyema
Onset	Acute	Very late	Very late	Acute	Acute	Chronic
Intervention	Local decortication	Debridement	Local decortication	Debridement	Debridement	Debridement
P.o. ventilation (h)	No	Yes (12 h)	Yes (12 h)	No	No	No
VAC changes in operating room (n)	1	2	4	2	2	3
Maximum suction (mmHg)	−75	−125	−125	−125	−100	−100
VAC duration (days)	4	12	18	9	11	9
Microbiological infection	Streptococcus	Staphylococcus	Staphylococcus	Staphylococcus and Pseudomonas	Streptococcus	Enterobacteria and Aspergillus
Antibiotic therapy (days)	10	12	7	6	7	19
Chest wall closed	Yes	Yes	Yes	Yes	Yes	Yes
Muscle flap	No	No	Musculus latissimus dorsi	No	Musculus latissimus dorsi	No
Hospitalization for VAC (days)	22	33	29	11	24	12
Outcome	Healed	Healed	Healed	Healed	Healed	Healed

Course of Mini-VAC therapy

Local control of the infection and control of sepsis were satisfactory in all 6 patients treated by Mini-VAC therapy. The patients tolerated a suction of 75–125 mmHg and did not react with arrhythmia or haemodynamic complications due to the traction on the mediastinum during increases in suction. Membranes were not necessary for the protection of the lung parenchyma. Furthermore, the suction used did not create any air leaks or bleeding from the lung or the mediastinal structures. At the time of VAC installation, 2 patients were in a severe clinical condition with acute respiratory insufficiency and mechanical ventilation. The 2 ventilated patients were weaned from ventilatory support 12 h after implementing Mini-VAC therapy. In these patients, Mini-VAC therapy allowed an improved re-expansion of the residual lung. In all cases, Mini-VAC therapy resulted in the rapid eradication of local infection. The patients underwent 2.5 ± 1.5 debridements and Mini-VAC changes (every third to fifth day) in the operation theatre under general anaesthesia. The ALEXIS^® retractor was also changed at this time. In most of the cases, only a small amount of debridement was required at the Mini-VAC changes. After these procedures, the pleural cavity was visually and microbiologically determined to be clean. We therefore withdrew antibiotics when there were no signs of sepsis and the thoracic cavity had become sterile (mean time: 10.1 days).

Outcome of Mini-VAC therapy

All patients were successfully treated by Mini-VAC intrapleural therapy (Table 2). After Mini-VAC treatment only 1 patient underwent a small wound infection with secondary intention. In most of the cases, the dimension of the pleural cavity was also decreased by Mini-VAC therapy. We had only 2 patients with cavities that required a muscle flap closure. These 2 patients underwent a thoracomyoplasty by transposition of the the lattissimus dorsi muscle. The chest wall was closed during the same hospital stay for all patients.

All patients left the hospital in good health (Karnofsky index >70%) and with a non-infected pleural cavity. The mean hospital stay after VAC installation was 22 ± 11 days. The patients were discharged from our department with only oral non-steroidal anti-inflammatory drugs. No pleural empyema had recurred in any of the 6 patients at the 3-month follow-up. All patients reported a very good quality of life in an outpatient interview. The short-term aesthetic results of Mini-VAC therapy are very good (Fig. 2).

Figure 2:

Short-term aesthetic result after Mini-VAC therapy.

COMMENT

Following up on our first description of the feasibility of a new technique—Mini-VAC—in the treatment of pleural empyema, we now report our excellent experiences in the use of this Mini-VAC technique in daily clinical routine.

Some reports [5, 8–10] showed that patients with complex empyema can be successfully treated with intrapleural VAC therapy. The most important advantages of the VAC therapy are the rapid treatment of sepsis and local control of the pleural cavity. Suction therapy can also improve pulmonary function (re-expansion). The presence of bronchialpleural fistulas or residual lung tissue is not a contraindication to the VAC procedure, since small bronchialpleural fistulas can spontaneously close. Pleural VAC therapy can potentially alleviate morbidity and shorten the length of hospitalization. Outpatient treatment with VAC therapy is also possible. However, classical pleural VAC therapy requires an OWT, with rib resection [2, 3].

All of the advantages of the VAC treatment with OWT are also offered by the Mini-VAC procedure. Furthermore, the rate of success in empyema treatment and wound closure after Mini-VAC therapy in our study is substantially higher than that in groups with OWT and VAC treatment (Table 3). The basic component of the Mini-VAC therapy is a plastic wound retractor that allows access to the pleural space without the need for a mechanical retractor. These retractors are routinely used in thoracic surgery for video-assisted thoracoscopic anatomical lung resections.

Table 3:

Overview Mini-VAC vs classical VAC with open-window thoracostomy (OWT)

	Mini-VAC	VAC with OWT
	This study	Groetzner et al. [8]	Palmen et al. [10]	Saadi et al. [9]	Sziklavari et al. [5]
Number of patients	6	13	11	27	8
VAC changes in OR (n)	2.5 ± 1.5	–	0	6 (2–14)	2.1 (0–5)
Duration of VAC therapy (days)	11 ± 7	64 ± 45	31 ± 19	22 (5–66)	26 ± 18a
VAC-related adverse event (%)	0	0	0	3.7	0
Chest wall closure (%)	100	100	100	100	71.4
Hospital stay (days)	22 ± 11	44 ± 34	60 ± 41	44 (20–114)	22 ± 1
Recurrence (%)	0	15	9	3.5	0
Hospital mortality (%)	0	0	0	19	12.5

^aIncluding outpatient VAC therapy.

The first instillation of the Mini-VAC system must be performed under general anaesthesia, because the first operation also includes pus evacuation, debridement and flushing of the pleural cavity. The decision to perform only local decortication seems not to be disadvantageous; similar lung re-expansion was achieved by debridement alone without decortication in patients presenting with empyema [11].

Our patients underwent sponge changes in the operating theatre under general anaesthesia every second to third day, at which point the ALEXIS^® retractor was also changed. The frequency and the location of intrathoracic VAC changes in patients with OWT vary, as this part of the surgical treatment is not defined. Palmen et al. [10] changed the system in the surgical ward without anaesthesia every third to fifth day, or more often in cases of purulent secretion or increased infection. The number of Mini-VAC changes in our group seems to be somewhat smaller and, therefore, the Mini-VAC treatment time and hospital stays of these patients are clearly shorter (Table 3).

The decided advantage of the Mini-VAC technique is the lack of a need for OWT with the classical rib resection. OWT is associated with more postoperative pain and a lower rate of permanent chest wall closure.

A persistent stoma with minimal drainage may remain, which increases the likelihood of secondary colonization by microorganisms [12]. Therefore, the best way to treat a postempyema pleural space is by, e.g. muscle flap closure. However, the closure of the OWT depends on the patient's individual situation. The numbers and time periods of the closure strongly differ in the literature, especially for patients without VAC therapy. In our former study, we closed the VAC-induced OWT after a mean time of 3 months, but 2 patients rejected this procedure [5]. Groetzner et al. [8] performed direct surgical wound closure in all patients, but they used the VAC system for a mean period of 64 ± 45 (range 7–134 days). In the present study, we closed all of the chest walls of our Mini-VAC patients after a mean time of 11 ± 7 days during the same hospital stay, and no further hospitalization was necessary. This very early closure was possible due to the fast local control of the empyema and the abdication of rib resection.

An additional advantage of plastic wound retractors use is that they act also as a barrier that protects the soft tissue and wound from bacterial translocation. This could also be an underlying reason for the rapid and successful treatment and for the very early closure.

The majority of the patients had no major complications related to the Mini-VAC therapy. All patients left the hospital in good health (Karnofsky index >70%). Saadi et al. [9] reported an 82% survival rate; 5 of 27 patients died during or after OWT and VAC therapy, and there was one VAC-related complication.

Open questions for the Mini-VAC treatment are whether this new technique is applicable in patients with bronchopleural fistula, and whether simultaneous antibiotic flushing during VAC therapy is possible (VAC Instill^®). However, our further experiences with VAC and OWT [5] support the implementation of this technique in patients with bronchopleural fistula. The role of VAC Instill^® has not yet been investigated.

Perhaps 1 or 2 patients in our group could be treated by classical surgery (e.g. thoracotomy/decortication). However, in these cases, we foresaw the risk of a (later) OWT. Our results suggest that, in all patients, the use of Mini-VAC therapy for the treatment of complex pleural empyema is very safe, rapid and successful. The greatest advantage of Mini-VAC is the ability to avoid OWT, which enables a short treatment with subsequent early chest wall closure.

Conflict of interest: none declared.