Application of pedicle combined muscle flaps in treatment of chronic empyema with huge irregular abscess cavity after pulmonary surgery: a case report and literature review

Abstract

Background

Chronic empyema is usually considered to be very challenging in clinical management and has a high mortality rate. On this basis, if combined with bronchopleural fistula (BPF) and huge irregular abscess cavity, there are not many treatment options available, and some patients may even develop cachexia due to long-term chronic consumption. The application of pedicled combined muscle flaps to repair and reconstruct according to the region of abscess cavity may improve the quality of life for such complex cases.

Case presentation

A 59-year-old male patient underwent surgical treatment for lung squamous cell carcinoma 2 years ago. Due to the low differentiation of malignant tumor, empyema complicated with BPF occurred after the fourth cycle of chemotherapy. His past medical history was free of other illnesses. The patient was admitted to our hospital for further treatment because of long-term chest tube drainage and obvious respiratory irritation symptoms such as cough during body position change. Chest computed tomography (CT) scan revealed a left-sided hydropneumothorax. Bronchoscopy revealed BPF. Considering that the volume of the abscess cavity did not shrink significantly after long-term drainage, we chose first-stage surgery to complete the debridement of empyema and the closure of the fistula. In the second-stage surgery, the combined pedicled muscle flaps were used to complete the filling in different areas of the huge irregular residual cavity. This surgical mode of staging and sub-regional treatment of abscess cavity has achieved satisfactory clinical results.

Conclusions

Utilizing the pedicled combined muscle flaps to address chronic empyema accompanied by a huge irregular abscess cavity shows promise as a treatment method for eliminating residual cavity in various regions.

Introduction

Chronic empyema with BPF caused by anatomical lobectomy or segmentectomy are not common complications to some extent. Once it occurs, it always appears in the form of difficult and complicated symptoms, and the treatment methods and standards always present multiple patterns based on the characteristics of different cases [1,2,3]. For some complicated cases of empyema associated with huge abscess cavity after pneumonectomy, it is often difficult to achieve success only by closed thoracic drainage or thoracoplasty. With the continuous progress of surgical technology, the improvement of medical equipment and the scientific rationality of perioperative period, the overall incidence of empyema with BPF is about 1% [4,5,6]. If some patients with refractory empyema have both huge irregular residual cavity and BPF, achieving clinical cure often requires complete filling of the residual cavity and closure of the fistula. If the residual cavity remains, it may cause secondary infection and lead to the recurrence of empyema [7].

We chose first-stage surgery to complete empyema debridement and use a endobronchial one-way valve (EBV) to complete fistula closure, and further reduce the volume of residual cavity and control infection by open-window thoracostomy (OWT). In the second-stage surgery, the pedicled combined muscle flaps were selected to complete the filling of abscess cavity in different regions. The treatment of this patient with complex empyema was completed through this staged surgical model. Postoperative follow-up showed no recurrence of empyema, which achieved the effect of clinical cure.

Case presentation

A 59-year-old male patient underwent left lower lobectomy and left upper lingual segment resection due to lung malignancy 2 years ago. The chest incisions were made at the 7th intercostal near the midaxillary line and the 5th intercostal near the anterior axillary line, with sizes of approximately 1.5 cm and 4.0 cm, respectively. Pathology showed moderate to poorly differentiated squamous cell carcinoma without metastasis to mediastinal lymph nodes (pT3N0M0). Before undergoing the 5th postoperative adjuvant chemotherapy, he experienced irritating cough, low fever, and chest tightness. A chest CT scan from an external medical facility revealed a significant accumulation of pneumothorax and effusion in the left thoracic cavity, along with pleural thickening and calcification. Due to the compression of the remaining lung, the abscess cavity was huge and irregular, essentially encompassing the entire left thoracic cavity. After the implementation of closed chest drainage, there was notable air leakage observed in the drainage bottle [(Fig. 1(A-D)]. The patient experienced a lack of improvement in their condition as a result of prolonged chest tube drainage. Upon admission to our hospital, bronchoscopy revealed that the lumen of upper lobe of left lung was unobstructed, with a smooth mucosa. However, there was a significant amount of secretion present in the apicoposterior segment of the left upper lung. A fistula measuring approximately 4 mm was observed in the left upper lobe’s lingual segment, with surgical sutures partially visible. A guide wire was employed to investigate the suture of the bronchial stump in the lower lobe of the left lung, and no obvious fistula was identified [(Fig. 2(A-C)]. According to the patient’s medical history, clinical symptoms and manifestations, we preliminarily diagnosed chronic empyema with BPF after lung cancer surgery. The patient, with a height of 182 cm, weight of 65 kg, and a body mass index (BMI) of 19.6 kg/m², required an individualized treatment plan due to a huge and irregular abscess cavity. The first stage of surgery involved OWT and closure of BPF. In the second-stage surgery, pedicled combined muscle flaps were transferred to various areas to fill the abscess cavity. Post-surgery, sensitive antibiotic treatment was administered following metagenomic next-generation sequencing (mNGS) detection of pus.

Fig. 1

Preoperative imaging data. A-D. The patient’s chest CT coronal scan showed that the abscess cavity at different levels of the left thorax was huge and irregular, and the remaining lung showed compressive change

Fig. 2

Images of the abscess cavity after OWT. A-B. The patient’s chest CT coronal scan revealed that the abscess cavity was distributed across multiple regions from top to bottom following OWT, with a reduced volume compared to the initial scan. (Red arrow)

Surgical strategy

First-stage surgery (empyema debridement + fistula closure)

Following successful double-lumen intubation under general anesthesia with balloon occlusion of the left main bronchus, the patient was positioned in a 90° lateral decubitus on the right side. The skin and subcutaneous tissue were carefully cut, with attention paid to protecting the latissimus dorsi (LD). Using rib scissors, the 3rd and 4th ribs were resected to access the residual cavity. Part of the thickened pleura and necrotic tissue were excised to expose the cavity, followed by thorough scraping of the pleural parietal pus using a curette. The mass was removed until the fresh tissue layer was exposed on the surface of the abscess cavity. The double-lumen endotracheal intubation was converted to single-lumen mode, followed by the use of a methylene blue test under bronchoscopy to locate the fistula. The fistula diameter was measured to be approximately 4 mm. A EBV was inserted through the bronchoscope’s working channel to close the fistula. Subsequently, the abscess cavity was washed with 3000 ml of warm saline, 150 ml of hydrogen peroxide, and 200 ml of diluted iodophor water. The volume of abscess cavity was estimated to be around 400 ml. The total duration of the first-stage surgery was approximately 2.1 h, with an intraoperative blood loss of about 80 ml. To reduce the abscess cavity and control infection in the short term, OWT was conducted following the initial surgery. The wound measured approximately 8 cm x 6 cm in diameter[Fig. 3(A, B)]. Based on the mNGS test results of the pus, Staphylococcus hemolyticus was identified as the pathogenic bacteria, and a one-week course of sensitive antibiotic was administered postoperatively (Piperacillin Sodium and Tazobactam Sodium 4.5 g + 0.9% 0.9% sodium chloride injection 50 ml Q8H) .

Fig. 3

Preoperative images of bronchoscopy. A. The lumen of the upper lobe of the left lung was unobstructed and the mucosa was smooth. B. A fistula of approximately 4 mm was visible in the lingual segment of the left upper lung, and surgical sutures were partially visible. C. A guide wire was used to explore the suture of the bronchial stump in the lower lobe of the left lung, and no obvious fistula was found

The dressing change continued for six months (Sterile gauze containing 5% povidone iodine solution was used to wipe the surface of the abscess cavity, and finally several dry and clean sterile gauze were used to fill part of the abscess cavity. The abscess cavity was treated by applying sterile gauze soaked in a dressing containing a 5% povidone-iodine solution, followed by filling part of the abscess cavity with clean, sterile gauze. Dressing changes were typically performed 1 to 2 times daily, depending on the level of wound exudation. Initially, twelve pieces of 8 cm x 10 cm sterile gauze were applied to the abscess cavity during each dressing change. However, as the abscess cavity shrank, the number of sterile gauze pieces of the same specification was adjusted to six), during which the pus culture remained negative, indicating that the abscess infection was initially controlled. Additionally, the patient’s nutritional status showed significant improvement, evidenced by a weight gain of 12% and a BMI of 21.98 kg/m². Subsequently, he prepared for the second-stage surgery.

Second-stage surgery (thoracomyoplasty)

To optimize the utilization of the autologous tissue flap, the broken ends of the 3rd and 4th remaining ribs were resected once more, and the 5th, 6th, 7th, and 8th ribs were further trimmed. The volume of the abscess cavity was re-evaluated, and its size was reduced to approximately 200 ml. Then the abscess cavity was debrided again. An incision was carefully made following the anatomical structures of the upper and outer edges of the pectoralis major (PM), as well as the outer edge of the LD (Starting two centimeters below the clavicle, the incision extended towards the posterior midline, reaching the level of the 11th rib in the lower back) (Fig. 4A). During the process of harvesting the muscle flaps, it is essential to protect the dominant blood vessels of the pectoralis major muscle, as well as the thoracodorsal arteries and veins. Subsequently, a combined muscle flap comprising the PM and LD (with serratus anterior) were meticulously created. The PM muscle flap measured approximately 15 cm x 10 cm, while the LD (with serratus anterior) muscle flap measured around 26 cm x 10 cm. Given the multi-regional and irregular nature of the abscess cavity, we initially cut and separated the pedicled LD muscle flap in a manner that created a bifurcated appearance. This allowed for a rich secondary muscle flap tissue volume without altering the total pedicle (Fig. 4B). The harvested combined muscle flaps were then divided into upper, middle, and lower regions to sequentially fill the abscess cavity. These muscle flaps were sutured and secured to the surrounding soft tissue to prevent displacement. Drainage tubes were subsequently placed in both the abscess cavity and subcutaneously for proper drainage (Fig. 4C). The total duration of the second-stage surgery was approximately 2.6 h, with intraoperative blood loss estimated at around 180 ml (Table 1). Post-surgery, anti-infection measures and adjuvant treatment were continued for one week. All drainage tubes were removed and the patient was discharged from hospital on the 7th day after surgery (Fig. 4D). Histopathological examination following surgery revealed no malignant tumor tissue. Follow-up continued for 18 months postoperatively, with no recurrence of empyema detected[Fig. 5(A-D)].An informed consent was obtained prior to this case report.

Fig. 4

Clinical data during surgery. A. The incision was designed according to the anatomic direction of pectoralis major and latissimus dorsi. B. The appearance of the chest wall incision after surgery. C. Sufficient volume of pedicled pectoralis major and latissimus dorsi muscle flap were fully dissociated, and the latissimus dorsi muscle flap was secondary dissection to form a bifurcation shape. (Black arrow). D. Appearance of the patient’s chest wall incision after 18 months of follow-up

Table 1 Patient characteristics

Fig. 5

Postoperative imaging data. A-D. The patient’s chest CT coronal scan revealed abscess cavity distributed in multiple regions of the left chest that were completely filled with pedicled combined muscle flaps, with no recurrence of empyema observed. (Green arrow)

Discussion and conclusion

Chronic empyema associated with BPF is a highly severe complication following pulmonary resection. The effectiveness of treatment typically hinges on proper drainage of pus, closure of fistula, and eradication of remaining cavity [8, 9]. Early surgical intervention may prevent the deterioration of the condition, but some patients may show obvious weakness when they experience infectious symptoms, losing the opportunity to repair the fistula early and eventually developing chronic empyema [10]. The common characteristics observed in these patients include prolonged drainage with a chest tube, chronic consumption by the body, and irregular changes in the huge abscess cavity in some patients with a larger body size. These factors can pose challenges in clinical management.

The optimal management strategy for treating chronic empyema associated with BPF remains a topic of debate in the medical field, especially in patients undergoing pulmonary surgery. While surgical treatment is often recommended as the primary approach, there are still numerous uncertainties that thoracic surgeons face post-treatment, despite advancements in medical technology [9, 11, 12]. Hippocrates documented chest drainage techniques over 2000 years ago, which are still utilized in modern medicine [13]. Historically, the treatment of chronic empyema has involved classic methods such as Heller’s thoracomyoplasty. The primary surgical approach consists of intraperiosteal resection of the ribs and thickened fibrous tissue, which may also necessitate the resection of a portion of the transverse process. This technique aims to preserve the periosteum and intercostal muscles, while also taking care to avoid damage to blood vessels and nerves. However, this method results in complete collapse of the thorax and is associated with significant surgical trauma. Ongoing research and advancements in treating empyema have established the removal of abscess cavities and closure of fistulas as essential components of clinical cure. The process of eliminating dead space in the body involves two main approaches: reducing the volume of the chest cavity and filling the remaining space [7, 14, 15]. The reduction of chest cavity volume typically requires the removal of a significant portion of the ribs to reshape the thorax. On the other hand, filling the remaining space involves using autologous tissue flap with a rich blood supply to effectively fill the abscess cavity, ultimately controlling infection and preventing its recurrence.

In cases of chronic empyema with a huge abscess cavity distributed across multiple regions, there have been reports of utilizing microsurgical techniques to transfer free myocutaneous flap for treatment. However, the use of pedicled tissue flap for treatment is uncommon [16,17,18]. The primary challenge lies in the insufficient volume of the tissue flap obtained, which may not adequately fill the residual cavity, potentially leading to empyema recurrence or healing failure due to migration. This particular patient has a tall and slender physique. Unfortunately, post-lung surgery complications have resulted in wide range of abscess cavity and complicated with BPF. Generally speaking, in order to achieve clinical cure, we often ensure that the infection in the abscess cavity is well controlled, the BPF is completely closed, and the volume of abscess cavity is reduced and controlled within ideal range. Based on the preoperative bronchoscopy and chest CT examination results, we showed that the shape of abscess cavity was complex and changeable, the abscess cavity was huge. In addition, it was also accompanied by BPF. How to finally complete the filling of the complex abscess cavity on the basis of controlling infection and closing fistula is the key to subsequent treatment, especially the repair and reconstruction of the abscess cavity under ideal conditions.

In recent years, there has been an increasing prevalence of autologous tissue flap transplantation in the management of chest wall infections and chronic empyema [19, 20]. Commonly utilized flaps include the PM, LD, and greater omentum. The PM muscle flap is superficial in location and has dual blood supply. As a pedicled muscle flap, it offers a large and thick area for harvesting, capable of covering the entire superficial chest wall space. The LD muscle flap, with its rich blood supply and minimal anatomical variations, provides advantages such as large volume, extensive range of motion, and high safety. It can be transferred to the entire ipsilateral chest, midline, and contralateral axillary folds [21, 22]. In this case, we made improvements on the basis of Heller’s thoracomyoplasty, primarily utilizing a muscle flap thoracoplasty approach combined with partial rib segment resection. Additionally, this method adheres to the concept of staged surgery, incorporating a transitional treatment involving window opening and dressing changes between the first and second stages of the procedure. This approach facilitated the spontaneous collapse of the chest and contributed to the reduction of the abscess cavity. Following the principle of adjacent repair, the abscess cavity was filled regionally, dividing it into three areas: upper, middle, and lower. The upper area was primarily addressed with PM muscle flap, whereas the middle and lower areas were predominantly treated with LD muscle flap and greater omentum flap. The LD is well-known as the largest and most dependable muscle flap, taking on a V-shaped form. The proximal end of the muscle can be pedicled by either the thoracodorsal blood vessels or the serratus branch [21, 23]. Considering that the abscess cavity of this patient was narrow and long, multi-spatial distribution and irregular, and the application of a single pedicled muscle flap could not meet the filling requirements, we used OWT to control infection based on the completion of empyema debridement and fistula closure in the first-stage surgery, which changes the volume of the abscess cavity or further promotes the expansion of the remaining lung, so as to create conditions for the second-stage surgery [24]. The practice of packing sterile gauze into the abscess cavity via an open wound primarily relied on the principle of siphon action, utilizing the pressure gradient between the inside and outside of the wound to facilitate the gradual drainage of pus along the gauze. This approach accelerated the outflow of pus, particularly in deeper cavities where pus tends to accumulate. The use of sterile gauze proved advantageous in ensuring unobstructed drainage, effectively preventing pus accumulation, controlling infections, and fostering the development of new granulation tissue [25]. When the residual cavity was reduced to the ideal range, the pedicled combined muscle flaps transfer were applied according to the abscess cavity area division to complete the repair and reconstruction. The case involved ongoing dressing changes for a duration of six months. The volume of the abscess cavity was reduced by nearly 50% compared to its original size, and the patient’s BMI showed significant improvement from baseline. However, managing the residual cavity remained a considerable challenge. Given the patient’s psychological trauma and strong desire for surgical intervention, we formulated an individualized treatment plan for him. In consideration of the unique circumstances surrounding the patient’s abscess cavity, we attempted to use a portion of the LD divided into bifurcations for the first time. Despite the utilization of the pedicle PM for closure, a residual defect in the region above the abscess cavity persisted. The primary focus of these procedures was to ensure adequate blood supply to the dominant vessels, emphasizing the necessity for the bifurcated secondary muscle flap to possess substantial tissue rather than a fragile composition. It is crucial to maintain the tissue integrity of the pedicle of the muscle flap to prevent potential muscle necrosis resulting from inadequate blood flow. By eliminating dead space and minimizing postoperative effusion and blood accumulation, the likelihood of empyema infection recurrence is significantly reduced.

In cases of chronic empyema with huge irregular residual cavities, our use of the pedicle combined muscle flaps sub-regional treatment method shows promise in clinical practice. However, it is essential to be prepared with multiple alternatives should the pedicled muscle flap approach fail. For instance, treatment models utilizing free myocutaneous flap or greater omentum to fill the abscess cavity exist, although the former necessitates microsurgery and carries higher surgical risks. The latter option involves additional abdominal trauma, and the volume of the omentum cannot be reliably assessed preoperatively. Regardless of treatment strategy, it is essential to fully control infection and close BPF in order to create optimal conditions for the second-stage surgery and improve the chances of curing empyema. Therefore, utilizing combined pedicled muscle flaps to address chronic empyema with BPF is a viable and effective surgical approach. These muscle flaps offer flexibility in design, ease of acquisition, and demonstrate positive clinical outcomes.